U.S. patent application number 12/172760 was filed with the patent office on 2009-02-12 for injection system and method.
This patent application is currently assigned to PARTICLE DRILLING TECHNOLOGIES, INC.. Invention is credited to Joseph Estes, Greg Galloway, Jim Terry, Gordon Tibbitts, Jason Tichenor, Darrell Traylor, Adrian Vuyk, JR., Donald Woods.
Application Number | 20090038856 12/172760 |
Document ID | / |
Family ID | 40345408 |
Filed Date | 2009-02-12 |
United States Patent
Application |
20090038856 |
Kind Code |
A1 |
Vuyk, JR.; Adrian ; et
al. |
February 12, 2009 |
Injection System And Method
Abstract
An injection system and method is described. In several
exemplary embodiments, the injection system and method may be a
part of, and/or used with, a system and method for excavating a
subterranean formation.
Inventors: |
Vuyk, JR.; Adrian; (Houston,
TX) ; Terry; Jim; (Houston, TX) ; Tibbitts;
Gordon; (Murray, UT) ; Galloway; Greg;
(Conroe, TX) ; Estes; Joseph; (Moody, TX) ;
Tichenor; Jason; (Spring, TX) ; Traylor; Darrell;
(Missouri City, TX) ; Woods; Donald; (San Antonio,
TX) |
Correspondence
Address: |
BRACEWELL & GIULIANI LLP
P.O. BOX 61389
HOUSTON
TX
77208-1389
US
|
Assignee: |
PARTICLE DRILLING TECHNOLOGIES,
INC.
HOUSTON
TX
|
Family ID: |
40345408 |
Appl. No.: |
12/172760 |
Filed: |
July 14, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11773355 |
Jul 3, 2007 |
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12172760 |
|
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60959207 |
Jul 12, 2007 |
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Current U.S.
Class: |
175/65 ;
175/217 |
Current CPC
Class: |
E21B 7/18 20130101 |
Class at
Publication: |
175/65 ;
175/217 |
International
Class: |
E21B 7/18 20060101
E21B007/18 |
Claims
1. A method of injecting an impactor and fluid slurry into a high
pressure drilling fluid stream, the method comprising: pressurizing
the impactor and fluid slurry in a concrete pump to a set pressure
value, wherein the set pressure value is approximately the drilling
fluid stream pressure value and wherein the set pressure exceeds
ambient pressure; discharging the pressurized impactor and fluid
slurry from the concrete pump to a slurry discharge line;
maintaining the pressure in the slurry discharge line substantially
at the set pressure; and injecting the pressurized impactor and
fluid slurry into the slurry discharge line to the high pressure
drilling fluid stream to thereby form a drilling fluid stream
having impactors.
2. The method of claim 1, the concrete pump having a first and a
second cylinder each having an inlet, a first and second piston
reciprocatingly disposed in the first and second cylinder
respectively, a mixing feed chamber in selective communication with
each inlet, the mixing feed chamber at substantially ambient
pressure, wherein each inlet is selectively in fluid communication
with the slurry discharge line.
3. The method of claim 2, wherein the concrete pump further
comprises a first transfer tube in selective communication between
the first inlet and the first cylinder inlet and the discharge
circuit and a second transfer tube in selective communication
between the second inlet and the second cylinder inlet and the
slurry discharge line, the method further comprising synchronizing
the communication between the inlet on the first cylinder and the
first transfer tube when the first piston is in a discharge stroke,
thereby isolating the slurry discharge line from the mixing feed
chamber.
4. The method of claim 3 further comprising synchronizing the
communication between the inlet on the second cylinder and the
second transfer tube when the second piston is in a discharge
stroke, thereby isolating the slurry discharge line from the mixing
feed chamber.
5. The method of claim 2, wherein the concrete pump further
comprises a transfer tube having an entrance selectively disposed
in communication between the inlet on the first cylinder and the
slurry discharge line when the first piston is in a discharge
stroke and in communication between the inlet on the second
cylinder and the discharge line when the second piston is in a
discharge stroke, the transfer tube further having a shroud
circumscribing the transfer tube entrance, the shroud blocking each
respective inlet from the mixing feed chamber as the transfer tube
is disposed into communication with the respective inlet thereby
isolating the slurry discharge line from the mixing feed
chamber.
6. The method of claim 1 further comprising allowing flow in the
slurry discharge line in a single direction from the concrete pump
discharge to the high pressure drilling fluid stream.
7. The method of claim 6, wherein the method of allowing flow in a
single direction comprises inserting a one way valve in the slurry
discharge line.
8. The method of claim 1 further comprising directing the drilling
fluid stream having impactors to a drilling string, discharging the
drilling fluid stream having impactors from the drilling string,
and boring through the earth.
9. The method of claim 1, wherein the slurry discharge line
pressure is maintained from about 1500 pounds per square inch to
about 2500 pounds per square inch.
10. The method of claim 1, wherein the slurry discharge pressure
line is maintained from about 2500 pounds per square inch to about
6000 pounds per square inch.
11. A fluid system for subterranean excavating comprising: a
pressurized drilling fluid line having high pressure drilling fluid
therein; a slurry discharge line having a first end and a second
end, the slurry discharge line connected on its first end to the
drilling fluid line; a concrete pump comprising a cylinder having
an opening, a piston reciprocatingly disposed in the cylinder, a
mixing feed chamber having a fluid and impactor slurry therein, the
mixing feed chamber in selective fluid communication with the
cylinder through the opening as the piston is reciprocating away
from the opening, a transfer tube moveable into selective
registration between the cylinder opening and the slurry discharge
line second end as the piston is reciprocating towards the opening,
and a pressure isolation member sealingly disposed between the
mixing feed chamber and the opening as the transfer tube is moving
into selective registration with the opening, thereby isolating the
slurry discharge line from the mixing feed chamber.
12. The fluid system of claim 11, wherein the concrete pump further
comprises a second cylinder having an opening and a second piston
reciprocatingly disposed therein, wherein the transfer tube is
selectively registerable between the second cylinder opening and
the slurry discharge line as the second piston reciprocatingly
moves towards the opening.
13. The fluid system of claim 11, wherein the concrete pump further
comprises a second cylinder having an opening and a second piston
reciprocatingly disposed therein and a second transfer tube,
wherein the second transfer tube is selectively registerable
between the second cylinder opening and the slurry discharge line
as the second piston reciprocatingly moves towards the opening.
14. The fluid system of claim 13, wherein the transfer tube
laterally moves in and out of registration with the opening along a
first line, and the second transfer tube laterally moves in and out
of registration with the second opening along a second line.
15. The fluid system of claim 13, wherein the transfer tube
laterally moves in and out of registration with the opening along a
first orbital path, and the second transfer tube laterally moves in
and out of registration with the second opening along a second
orbital path.
16. The fluid system of claim 11, wherein the slurry discharge line
is maintained at a set pressure suitable to inject the impactor and
fluid slurry into the high pressure drilling fluid stream.
17. The fluid system of claim 11, wherein the slurry discharge line
is maintained at a pressure of about 1500 pounds per square inch to
about 2500 pounds per square inch.
18. The fluid system of claim 11, wherein the slurry discharge line
is maintained at a pressure of about 2500 pounds per square inch to
about 6000 pounds per square inch.
19. The fluid system of claim 11, further comprising a seal
provided on an end of the transfer tube, the seal comprising, a
seal body, a bevel radially extending from the seal body past
transfer tube outer periphery, and a resilient member between the
seal body and the transfer tube.
20. The fluid system of claim 11, further comprising a seal
provided on an end of the transfer tube, the seal comprising, a
seal body, and a lubricant injection line communicating through the
seal body.
21. The fluid system of claim 11, further comprising a chamfered
profile extending coaxially away from a portion of the piston outer
periphery and on the end of the piston proximate to the
opening.
22. A method of earth boring comprising: pressurizing an impactor
and fluid slurry in a concrete pump to a set pressure that exceeds
ambient pressure; discharging the pressurized impactor and fluid
slurry from the concrete pump to a discharge circuit; maintaining
the pressure in the discharge circuit at substantially the set
pressure; directing the pressurized impactor and fluid slurry from
the discharge circuit to a drill string; and discharging the
impactor and fluid slurry from the drill string and boring through
the earth.
23. The method of claim 22, the concrete pump having a first and a
second cylinder each having an inlet, a first and second piston
reciprocatingly disposed in the first and second cylinder
respectively, a mixing feed chamber communicatable with each inlet,
the mixing feed chamber at substantially ambient pressure, wherein
each inlet is selectively in fluid communication with the discharge
circuit.
24. The method of claim 23, wherein the concrete pump further
comprises a first transfer tube in selective communication between
the first inlet and the first cylinder inlet and the discharge
circuit and a second transfer tube in selective communication
between the second inlet and the second cylinder inlet and the
discharge circuit, the method further comprising synchronizing the
communication between the inlet on the first cylinder and the first
transfer tube when the first piston is in a discharge stroke,
thereby isolating the discharge circuit from the mixing feed
chamber.
25. The method of claim 24 further comprising synchronizing the
communication between the inlet on the second cylinder and the
second transfer tube when the second piston is in a discharge
stroke, thereby isolating the discharge circuit from the mixing
feed chamber.
26. The method of claim 22, wherein the concrete pump further
comprises a transfer tube having an entrance selectively disposed
in communication between the inlet on the first cylinder and the
discharge circuit when the first piston is in a discharge stroke
and in communication between the inlet on the second cylinder and
the discharge circuit when the second piston is in a discharge
stroke, the transfer tube further having a shroud circumscribing
the entrance, the shroud blocking each inlet from the mixing feed
chamber as the transfer tube is disposed into communication with
the inlet thereby isolating the discharge circuit from the mixing
feed chamber.
27. The method of claim 22, wherein the discharge circuit comprises
a line having fluid pressurized by a second pressure source and a
slurry line communicating the pressurized impactor and fluid slurry
to the line, the method further comprising allowing flow in the
slurry line in a single direction from the first pressure source
discharge to the line.
28. The method of claim 27, wherein the method of allowing flow in
a single direction comprises inserting a one way valve in the
slurry line.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to and the benefit of
co-pending U.S. Provisional Application Ser. No. 60/959,207, filed
Jul. 12, 2007, the full disclosure of which is hereby incorporated
by reference herein. This application is a continuation in part of
U.S. utility patent application Ser. No. 11/773,355, attorney
docket number 13978.105084US, filed on Jul. 3, 2007, PCT patent
application serial number PCT/US07/72794, attorney docket number
13978.105084WO, filed on Jul. 3, 2007, U.S. provisional patent
application No. 60/899,135, filed on Feb. 2, 2007 (attorney docket
number 37163.00061); U.S. provisional patent application Ser. No.
60/818,480, filed on Jul. 3, 2006 (attorney docket no.
37163.00059); and pending application Ser. No. 10/897,196, filed on
Jul. 22, 2004 (attorney docket no. 13978.105012 formerly
37163.00012), the disclosures of which are incorporated herein by
reference.
[0002] This application is related to U.S. provisional patent
application Ser. No. 60/463,903, filed on Apr. 16, 2003 (attorney
docket no. 13978.105035 formerly 37163.00017); U.S. Pat. No.
6,386,300, issued on May 14, 2002, which was filed as application
Ser. No. 09/665,586 on Sep. 19, 2000 (attorney docket no.
13978.105037 formerly 37163.00023); U.S. Pat. No. 6,581,700, issued
on Jun. 24, 2003, which was filed as application Ser. No.
10/097,038 on Mar. 12, 2002 (attorney docket no. 13978.105034
formerly 37163.00024); U.S. Pat. No. 7,398,838, issued on Jul. 15,
2008, which was filed as application Ser. No. 11/204,981, filed on
Aug. 16, 2005 (attorney docket no. 37163.00006); U.S. Pat. No.
7,343,987, issued on Mar. 18, 2008, which was filed as application
Ser. No. 11/204,436, filed on Aug. 16, 2005 (attorney docket no.
13978.105041 formerly 37163.00007); pending application Ser. No.
11/204,862, filed on Aug. 16, 2005 (attorney docket no.
13978.105042 formerly 37163.00008); pending application Ser. No.
11/205,006, filed on Aug. 16, 2005 (attorney docket no.
13978.105038 formerly 37163.00009); pending application Ser. No.
11/204,722, filed on Aug. 16, 2005 (attorney docket no.
13978.105053 formerly 37163.00010); U.S. Pat. No. 7,398,839, issued
on Jul. 15, 2008, which was filed as application Ser. No.
11/204,442, filed on Aug. 16, 2005 (attorney docket no.
13978.105018 formerly 37163.00011); U.S. Pat. No. 7,258,176, issued
Aug. 21, 2007, which was filed as application Ser. No. 10/825,338,
filed on Apr. 15, 2004 (attorney docket no. 13978.105060 formerly
37163.00018); pending application Ser. No. 10/558,181, filed on May
27, 2004 (attorney docket no. 13978.105032 formerly 37163.00045);
pending application Ser. No. 11/344,805, filed on Feb. 1, 2006
(attorney docket no. 13978.105059 formerly 37163.00047); pending
application No. 60/746,855, filed on May 9, 2006 (attorney docket
no. 13978.105071 formerly 37163.00057); the disclosures of which
are incorporated herein by reference.
BACKGROUND
[0003] This disclosure generally relates to a system and method for
injecting particles into a flow region in connection with, for
example, excavating a formation. The formation may be excavated in
order to, for example, form a wellbore for the purpose of oil and
gas recovery, construct a tunnel, or form other excavations in
which the formation is cut, milled, pulverized, scraped, sheared,
indented, and/or fractured, hereinafter referred to collectively as
cutting.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] FIG. 1 is an isometric view of an excavation system
according to an embodiment.
[0005] FIG. 2 illustrates an impactor impacted with a
formation.
[0006] FIG. 3 illustrates an impactor embedded into the formation
at an angle to a normalized surface plane of the target
formation.
[0007] FIG. 4 illustrates an impactor impacting a formation with a
plurality of fractures induced by the impact.
[0008] FIG. 5 is an elevational view of a drilling system utilizing
a first embodiment of a drill bit.
[0009] FIG. 6 is a top plan view of the bottom surface of a well
bore formed by the drill bit of FIG. 5.
[0010] FIG. 7 is a sectional view of a sequencing valve for use
with one or more of the embodiments of the present disclosure.
[0011] FIG. 8A is a sectional view of an alternate embodiment of a
sequencing valve for use with one or more of the embodiments of the
present disclosure.
[0012] FIG. 8B is a sectional view of an alternate embodiment of a
sequencing valve for use with one or more of the embodiments of the
present disclosure.
[0013] FIG. 9 is a schematic view of an injection system according
to another embodiment.
[0014] FIG. 10 is an elevational view of an injection system
according to another embodiment.
[0015] FIG. 11 is a perspective partially exploded view of an
embodiment of a concrete pump.
[0016] FIG. 12a is a perspective view of an embodiment of a
selector valve assembly.
[0017] FIG. 12b is an overhead view of the selector valve assembly
of FIG. 12a.
[0018] FIG. 12c is a frontal view of the selector valve assembly of
FIG. 12a.
[0019] FIGS. 13a-13h depict, in frontal and perspective views, an
operational sequence of an embodiment of a selector valve
assembly.
[0020] FIG. 14 is a perspective view of an embodiment of a selector
valve assembly.
[0021] FIG. 15 is a frontal view of an embodiment for a valve
seal.
[0022] FIG. 16 is a sectional view of a portion of the valve seal
of FIG. 15.
[0023] FIG. 17 is a perspective view of an embodiment of a seal
with a transfer tube.
[0024] FIG. 18 is a cross sectional view of the seal of FIG.
17.
DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS
[0025] In the drawings and description that follows, like parts are
marked throughout the specification and drawings with the same
reference numerals, respectively. The drawings are not necessarily
to scale. Certain features of the disclosure may be shown
exaggerated in scale or in somewhat schematic form and some details
of conventional elements may not be shown in the interest of
clarity and conciseness. The present disclosure is susceptible to
embodiments of different forms. Specific embodiments are described
in detail and are shown in the drawings, with the understanding
that the present disclosure is to be considered an exemplification
of the principles of the disclosure, and is not intended to limit
the disclosure to that illustrated and described herein. It is to
be fully recognized that the different teachings of the embodiments
discussed below may be employed separately or in any suitable
combination to produce desired results. The various characteristics
mentioned above, as well as other features and characteristics
described in more detail below, will be readily apparent to those
skilled in the art upon reading the following detailed description
of the embodiments, and by referring to the accompanying drawings.
This application claims priority to and the benefit of co-pending
U.S. Provisional Application Ser. No. 60/959,207, filed Jul. 12,
2007, the full disclosure of which is hereby incorporated by
reference herein.
[0026] FIGS. 1 and 2 illustrate an embodiment of an excavation
system 1 comprising the use of solid material particles, or
impactors, 100 to engage and excavate a subterranean formation 52
to create a wellbore 70. The excavation system 1 may comprise a
pipe string 55 comprised of collars 58, pipe 56, and a kelly 50. An
upper end of the kelly 50 may interconnect with a lower end of a
swivel quill 26. An upper end of the swivel quill 26 may be
rotatably interconnected with a swivel 28. The swivel 28 may
include a top drive assembly (not shown) to rotate the pipe string
55. Alternatively, the excavation system 1 may further comprise a
body member such as, for example, a drill bit 60 to cut the
formation 52 in cooperation with the solid material impactors 100.
The drill bit 60 may be attached to the lower end 55B of the pipe
string 55 and may engage a bottom surface 66 of the wellbore 70.
The drill bit 60 may be a roller cone bit, a fixed cutter bit, an
impact bit, a spade bit, a mill, an impregnated bit, a natural
diamond bit, or other suitable implement for cutting rock or
earthen formation. Referring to FIG. 1, the pipe string 55 may
include a feed, or upper, end 55A located substantially near the
excavation rig 5 and a lower end 55B including a nozzle 64
supported thereon. The lower end 55B of the string 55 may include
the drill bit 60 supported thereon. The excavation system 1 is not
limited to excavating a wellbore 70. The excavation system and
method may also be applicable to excavating a tunnel, a pipe chase,
a mining operation, or other excavation operation wherein earthen
material or formation may be removed.
[0027] In another exemplary embodiment, the present system may be
used to inject any solid particulate material into a wellbore.
Exemplary particles may be magnetic or non-magnetic solid
particles. Exemplary uses of the of the present system include, but
are not limited to, casing exits, preventing seepage loss, and
fracturing a formation.
[0028] To excavate the wellbore 70, the swivel 28, the swivel quill
26, the kelly 50, the pipe string 55, and a portion of the drill
bit 60, if used, may each include an interior passage that allows
circulation fluid to circulate through each of the aforementioned
components. The circulation fluid may be withdrawn from a tank 6,
pumped by a pump 2, through a through medium pressure capacity line
8, through a medium pressure capacity flexible hose 42, through a
gooseneck 36, through the swivel 28, through the swivel quill 26,
through the kelly 50, through the pipe string 55, and through the
bit 60.
[0029] The excavation system 1 further comprises at least one
nozzle 64 on the lower 55B of the pipe string 55 for accelerating
at least one solid material impactor 100 as they exit the pipe
string 100. The nozzle 64 is designed to accommodate the impactors
100, such as an especially hardened nozzle, a shaped nozzle, or an
"impactor" nozzle, which may be particularly adapted to a
particular application. The nozzle 64 may be a type that is known
and commonly available. The nozzle 64 may further be selected to
accommodate the impactors 100 in a selected size range or of a
selected material composition. Nozzle size, type, material, and
quantity may be a function of the formation being cut, fluid
properties, impactor properties, and/or desired hydraulic energy
expenditure at the nozzle 64. If a drill bit 60 is used, the nozzle
or nozzles 64 may be located in the drill bit 60.
[0030] The nozzle 64 may alternatively be a conventional
dual-discharge nozzle. Such dual discharge nozzles may generate:
(1) a radially outer circulation fluid jet substantially encircling
a jet axis, and/or (2) an axial circulation fluid jet substantially
aligned with and coaxial with the jet axis, with the dual discharge
nozzle directing a majority by weight of the plurality of solid
material impactors into the axial circulation fluid jet. A dual
discharge nozzle 64 may separate a first portion of the circulation
fluid flowing through the nozzle 64 into a first circulation fluid
stream having a first circulation fluid exit nozzle velocity, and a
second portion of the circulation fluid flowing through the nozzle
64 into a second circulation fluid stream having a second
circulation fluid exit nozzle velocity lower than the first
circulation fluid exit nozzle velocity. The plurality of solid
material impactors 100 may be directed into the first circulation
fluid stream such that a velocity of the plurality of solid
material impactors 100 while exiting the nozzle 64 is substantially
greater than a velocity of the circulation fluid while passing
through a nominal diameter flow path in the lower end 55B of the
pipe string 55, to accelerate the solid material impactors 100.
[0031] Each of the individual impactors 100 is structurally
independent from the other impactors. For brevity, the plurality of
solid material impactors 100 may be interchangeably referred to as
simply the impactors 100. The plurality of solid material impactors
100 may be substantially rounded and have either a substantially
non-uniform outer diameter or a substantially uniform outer
diameter. The solid material impactors 100 may be substantially
spherically shaped, non-hollow, formed of rigid metallic material,
and having high compressive strength and crush resistance, such as
steel shot, ceramics, depleted uranium, and multiple component
materials. Although the solid material impactors 100 may be
substantially a non-hollow sphere, alternative embodiments may
provide for other types of solid material impactors, which may
include impactors 100 with a hollow interior. The impactors may be
magnetic or non-magnetic. The impactors may be substantially rigid
and may possess relatively high compressive strength and resistance
to crushing or deformation as compared to physical properties or
rock properties of a particular formation or group of formations
being penetrated by the wellbore 70.
[0032] The impactors may be of a substantially uniform mass,
grading, or size. The solid material impactors 100 may have any
suitable density for use in the excavation system 1. For example,
the solid material impactors 100 may have an average density of at
least 470 pounds per cubic foot.
[0033] Alternatively, the solid material impactors 100 may include
other metallic materials, including tungsten carbide, copper, iron,
or various combinations or alloys of these and other metallic
compounds. The impactors 100 may also be composed of non-metallic
materials, such as ceramics, or other man-made or substantially
naturally occurring non-metallic materials. Also, the impactors 100
may be crystalline shaped, angular shaped, sub-angular shaped,
selectively shaped, such as like a torpedo, dart, rectangular, or
otherwise generally non-spherically shaped.
[0034] The impactors 100 may be selectively introduced into a fluid
circulation system, such as illustrated in FIG. 1, near an
excavation rig 5, circulated with the circulation fluid (or "mud"),
and accelerated through at least one nozzle 64. "At the excavation
rig" or "near an excavation rig" may also include substantially
remote separation, such as a separation process that may be at
least partially carried out on the sea floor.
[0035] Introducing the impactors 100 into the circulation fluid may
be accomplished by any of several known techniques. For example,
the impactors 100 may be provided in an impactor storage tank 94
near the rig 5 or in a storage bin 82. A screw elevator 14 may then
transfer a portion of the impactors at a selected rate from the
storage tank 94, into a slurrification tank 98. A pump 10, such as
a progressive cavity pump may transfer a selected portion of the
circulation fluid from a mud tank 6, into the slurrification tank
98 to be mixed with the impactors 100 in the tank 98 to form an
impactor concentrated slurry. An impactor introducer 96 may be
included to pump or introduce a plurality of solid material
impactors 100 into the circulation fluid before circulating a
plurality of impactors 100 and the circulation fluid to the nozzle
64. The impactor introducer 96 may be a progressive cavity pump
capable of pumping the impactor concentrated slurry at a selected
rate and pressure through a slurry line 88, through a slurry hose
38, through an impactor slurry injector head 34, and through an
injector port 30 located on the gooseneck 36, which may be located
atop the swivel 28. The swivel 36, including the through bore for
conducting circulation fluid therein, may be substantially
supported on the feed, or upper, end of the pipe string 55 for
conducting circulation fluid from the gooseneck 36 into the latter
end 55a. The upper end 55A of the pipe string 55 may also include
the kelly 50 to connect the pipe 56 with the swivel quill 26 and/or
the swivel 28. The circulation fluid may also be provided with
rheological properties sufficient to adequately transport and/or
suspend the plurality of solid material impactors 100 within the
circulation fluid.
[0036] The solid material impactors 100 may also be introduced into
the circulation fluid by withdrawing the plurality of solid
material impactors 100 from a low pressure impactor source 98 into
a high velocity stream of circulation fluid, such as by venturi
effect. For example, when introducing impactors 100 into the
circulation fluid, the rate of circulation fluid pumped by the mud
pump 2 may be reduced to a rate lower than the mud pump 2 is
capable of efficiently pumping. In such event, a lower volume mud
pump 4 may pump the circulation fluid through a medium pressure
capacity line 24 and through the medium pressure capacity flexible
hose 40.
[0037] The circulation fluid may be circulated from the fluid pump
2 and/or 4, such as a positive displacement type fluid pump,
through one or more fluid conduits 8, 24, 40, 42, into the pipe
string 55. The circulation fluid may then be circulated through the
pipe string 55 and through the nozzle 64. The circulation fluid may
be pumped at a selected circulation rate and/or a selected pump
pressure to achieve a desired impactor and/or fluid energy at the
nozzle 64.
[0038] The pump 4 may also serve as a supply pump to drive the
introduction of the impactors 100 entrained within an impactor
slurry, into the high pressure circulation fluid stream pumped by
mud pumps 2 and 4. Pump 4 may pump a percentage of the total rate
of fluid being pumped by both pumps 2 and 4, such that the
circulation fluid pumped by pump 4 may create a venturi effect
and/or vortex within the injector head 34 that inducts the impactor
slurry being conducted through the line 42, through the injector
head 34, and then into the high pressure circulation fluid
stream.
[0039] From the swivel 28, the slurry of circulation fluid and
impactors may circulate through the interior passage in the pipe
string 55 and through the nozzle 64. As described above, the nozzle
64 may alternatively be at least partially located in the drill bit
60. Each nozzle 64 may include a reduced inner diameter as compared
to an inner diameter of the interior passage in the pipe string 55
immediately above the nozzle 64. Thereby, each nozzle 64 may
accelerate the velocity of the slurry as the slurry passes through
the nozzle 64. The nozzle 64 may also direct the slurry into
engagement with a selected portion of the bottom surface 66 of
wellbore 70. The nozzle 64 may also be rotated relative to the
formation 52 depending on the excavation parameters. To rotate the
nozzle 64, the entire pipe string 55 may be rotated or only the
nozzle 64 on the end of the pipe string 55 may be rotated while the
pipe string 55 is not rotated. Rotating the nozzle 64 may also
include oscillating the nozzle 64 rotationally back and forth as
well as vertically, and may further include rotating the nozzle 64
in discrete increments. The nozzle 64 may also be maintained
rotationally substantially stationary.
[0040] The circulation fluid may be substantially continuously
circulated during excavation operations to circulate at least some
of the plurality of solid material impactors 100 and the formation
cuttings away from the nozzle 64. The impactors 100 and fluid
circulated away from the nozzle 64 may be circulated substantially
back to the excavation rig 5, or circulated to a substantially
intermediate position between the excavation rig 5 and the nozzle
64.
[0041] If the drill bit 60 is used, the drill bit 60 may be rotated
relative to the formation 52 and engaged therewith by an axial
force (WOB) acting at least partially along the wellbore axis 75
near the drill bit 60. The bit 60 may also comprise a plurality of
bit cones 62, which also may rotate relative to the bit 60 to cause
bit teeth secured to a respective cone to engage the formation 52,
which may generate formation cuttings substantially by crushing,
cutting, or pulverizing a portion of the formation 52. The bit 60
may also be comprised of a fixed cutting structure that may be
substantially continuously engaged with the formation 52 and create
cuttings primarily by shearing and/or axial force concentration to
fail the formation, or create cuttings from the formation 52. To
rotate the bit 60, the entire pipe string 55 may be rotated or only
the bit 60 on the end of the pipe string 55 may be rotated while
the pipe string 55 is not rotated. Rotating the drill bit 60 may
also include oscillating the drill bit 60 rotationally back and
forth as well as vertically, and may further include rotating the
drill bit 60 in discrete increments.
[0042] Also alternatively, the excavation system 1 may comprise a
pump, such as a centrifugal pump, having a resilient lining that is
compatible for pumping a solid-material laden slurry. The pump may
pressurize the slurry to a pressure greater than the selected mud
pump pressure to pump the plurality of solid material impactors 100
into the circulation fluid. The impactors 100 may be introduced
through an impactor injection port, such as port 30. Other
alternative embodiments for the system 1 may include an impactor
injector for introducing the plurality of solid material impactors
100 into the circulation fluid.
[0043] As the slurry is pumped through the pipe string 55 and out
the nozzles 64, the impactors 100 may engage the formation with
sufficient energy to enhance the rate of formation removal or
penetration (ROP). The removed portions of the formation may be
circulated from within the wellbore 70 near the nozzle 64, and
carried suspended in the fluid with at least a portion of the
impactors 100, through a wellbore annulus between the OD of the
pipe string 55 and the ID of the wellbore 70.
[0044] At the excavation ring 5, the returning slurry of
circulation fluid, formation fluids (if any), cuttings, and
impactors 100 may be diverted at a nipple 76, which may be
positioned on a BOP stack 74. The returning slurry may flow from
the nipple 76, into a return flow line 15, which maybe comprised of
tubes 48, 45, 16, 12 and flanges 46, 47. The return line 15 may
include an impactor reclamation tube assembly 44, as illustrated in
FIG. 1, which may preliminarily separate a majority of the
returning impactors 100 from the remaining components of the
returning slurry to salvage the circulation fluid for recirculation
into the present wellbore 70 or another wellbore. At least a
portion of the impactors 100 may be separated from a portion of the
cuttings by a series of screening devices, such as the vibrating
classifiers 84, to salvage a reusable portion of the impactors 100
for reuse to re-engage the formation 52. A majority of the cuttings
and a majority of non-reusable impactors 100 may also be
discarded.
[0045] The reclamation tube assembly 44 may operate by rotating
tube 45 relative to tube 16. An electric motor assembly 22 may
rotate tube 44. The reclamation tube assembly 44 comprises an
enlarged tubular 45 section to reduce the return flow slurry
velocity and allow the slurry to drop below a terminal velocity of
the impactors 100, such that the impactors 100 can no longer be
suspended in the circulation fluid and may gravitate to a bottom
portion of the tube 45. This separation function may be enhanced by
placement of magnets near and along a lower side of the tube 45.
The impactors 100 and some of the larger or heavier cuttings may be
discharged through discharge port 20. The separated and discharged
impactors 100 and solids discharged through discharge port 20 may
be gravitationally diverted into a vibrating classifier 84 or may
be pumped into the classifier 84. A pump (not shown) capable of
handling impactors and solids, such as a progressive cavity pump
may be situated in communication with the flow line discharge port
20 to conduct the separated impactors 100 selectively into the
vibrating separator 84 or elsewhere in the circulation fluid
circulation system.
[0046] The excavation system 1 creates a mass-velocity relationship
in a plurality of the solid material impactors 100, such that an
impactor 100 may have sufficient energy to structurally alter the
formation 52 in a zone of a point of impact. The mass-velocity
relationship may be satisfied as sufficient when a substantial
portion by weight of the solid material impactors 100 may by virtue
of their mass and velocity at the exit of the nozzle 64, create a
structural alteration as claimed or disclosed herein. Impactor
velocity to achieve a desired effect upon a given formation may
vary as a function of formation compressive strength, hardness, or
other rock properties, and as a function of impactor size and
circulation fluid rheological properties. A substantial portion
means at least five percent by weight of the plurality of solid
material impactors that are introduced into the circulation
fluid.
[0047] The impactors 100 for a given velocity and mass of a
substantial portion by weight of the impactors 100 are subject to
the following mass-velocity relationship. The resulting kinetic
energy of at least one impactor 100 exiting a nozzle 64 is at least
0.075 Ft.Lbs or has a minimum momentum of 0.0003 Lbf.Sec.
[0048] Kinetic energy is quantified by the relationship of an
object's mass and its velocity. The quantity of kinetic energy
associated with an object is calculated by multiplying its mass
times its velocity squared. To reach a minimum value of kinetic
energy in the mass-velocity relationship as defined, small
particles such as those found in abrasives and grits, must have a
significantly high velocity due to the small mass of the particle.
A large particle, however, needs only moderate velocity to reach an
equivalent kinetic energy of the small particle because its mass
may be several orders of magnitude larger.
[0049] The velocity of a substantial portion by weight of the
plurality of solid material impactors 100 immediately exiting a
nozzle 64 may be as slow as 100 feet per second and as fast as 1000
feet per second, immediately upon exiting the nozzle 64.
[0050] The velocity of a majority by weight of the impactors 100
may be substantially the same, or only slightly reduced, at the
point of impact of an impactor 100 at the formation surface 66 as
compared to when leaving the nozzle 64. Thus, it may be appreciated
by those skilled in the art that due to the close proximity of a
nozzle 64 to the formation being impacted, the velocity of a
majority of impactors 100 exiting a nozzle 64 may be substantially
the same as a velocity of an impactor 100 at a point of impact with
the formation 52. Therefore, in many practical applications, the
above velocity values may be determined or measured at
substantially any point along the path between near an exit end of
a nozzle 64 and the point of impact, without material deviation
from the scope of this disclosure.
[0051] In addition to the impactors 100 satisfying the
mass-velocity relationship described above, a substantial portion
by weight of the solid material impactors 100 have an average mean
diameter of between approximately 0.050 to 0.500 of an inch,
including increments of 0.01 inches in this range
[0052] To excavate a formation 52, the excavation implement, such
as a drill bit 60 or impactor 100, must overcome minimum, in-situ
stress levels or toughness of the formation 52. These minimum
stress levels are known to typically range from a few thousand
pounds per square inch, to in excess of 65,000 pounds per square
inch. To fracture cut, or plastically deform a portion of formation
52, force exerted on that portion of the formation 52 typically
should exceed the minimum, in-situ stress threshold of the
formation 52. When an impactor 100 first initiates contact with a
formation, the unit stress exerted upon the initial contact point
may be much higher than 10,000 pounds per square inch, and may be
well in excess of one million pounds per square inch. The stress
applied to the formation 52 during contact is governed by the force
the impactor 100 contacts the formation with and the area of
contact of the impactor with the formation. The stress is the force
divided by the area of contact. The force is governed by Impulse
Momentum theory whereby the time at which the contact occurs
determines the magnitude of the force applied to the area of
contact. In cases where the particle is contacting a relatively
hard surface at an elevated velocity, the force of the particle
when in contact with the surface is not constant, but is better
described as a spike. However, the force need not be limited to any
specific amplitude or duration. The magnitude of the spike load can
be very large and occur in just a small fraction of the total
impact time. If the area of contact is small the unit stress can
reach values many times in excess of the in situ failure stress of
the rock, thus guaranteeing fracture initiation and propagation and
structurally altering the formation 52.
[0053] A substantial portion by weight of the solid material
impactors 100 may apply at least 5000 pounds per square inch of
unit stress to a formation 52 to create the structurally altered
zone Z in the formation. The structurally altered zone Z is not
limited to any specific shape or size, including depth or width.
Further, a substantial portion by weight of the impactors 100 may
apply in excess of 20,000 pounds per square inch of unit stress to
the formation 52 to create the structurally altered zone Z in the
formation. The mass-velocity relationship of a substantial portion
by weight of the plurality of solid material impactors 100 may also
provide at least 30,000 pounds per square inch of unit stress.
[0054] A substantial portion by weight of the solid material
impactors 100 may have any appropriate velocity to satisfy the
mass-velocity relationship. For example, a substantial portion by
weight of the solid material impactors may have a velocity of at
least 100 feet per second when exiting the nozzle 64. A substantial
portion by weight of the solid material impactors 100 may also have
a velocity of at least 100 feet per second and as great as 1200
feet per second when exiting the nozzle 64. A substantial portion
by weight of the solid material impactors 100 may also have a
velocity of at least 100 feet per second and as great as 750 feet
per second when exiting the nozzle 64. A substantial portion by
weight of the solid material impactors 100 may also have a velocity
of at least 350 feet per second and as great as 500 feet per second
when exiting the nozzle 64.
[0055] Impactors 100 may be selected based upon physical factors
such as size, projected velocity, impactor strength, formation 52
properties and desired impactor concentration in the circulation
fluid. Such factors may also include; (a) an expenditure of a
selected range of hydraulic horsepower across the one or more
nozzles, (b) a selected range of circulation fluid velocities
exiting the one or more nozzles or impacting the formation, and (c)
a selected range of solid material impactor velocities exiting the
one or more nozzles or impacting the formation, (d) one or more
rock properties of the formation being excavated, or (e), any
combination thereof.
[0056] Referring to FIGS. 1-4, a substantial portion by weight of
the impactors 100 may engage the formation 52 with sufficient
energy to enhance creation of a wellbore 70 through the formation
52 by any or a combination of different impact mechanisms. First,
an impactor 100 may directly remove a larger portion of the
formation 52 than may be removed by abrasive-type particles. In
another mechanism, an impactor 100 may penetrate into the formation
52 without removing formation material from the formation 52. A
plurality of such formation penetrations, such as near and along an
outer perimeter of the wellbore 70 may relieve a portion of the
stresses on a portion of formation being excavated, which may
thereby enhance the excavation action of other impactors 100 or the
drill bit 60. Third, an impactor 100 may alter one or more physical
properties of the formation 52. Such physical alterations may
include creation of micro-fractures and increased brittleness in a
portion of the formation 52, which may thereby enhance
effectiveness the impactors 100 in excavating the formation 52. The
constant scouring of the bottom of the borehole also prevents the
build up of dynamic filtercake, which can significantly increase
the apparent toughness of the formation 52.
[0057] FIG. 2 illustrates an impactor 100 that has been impaled
into a formation 52, such as a lower surface 66 in a wellbore 70.
For illustration purposes, the surface 66 is illustrated as
substantially planar and transverse to the direction of impactor
travel 100a. The impactors 100 circulated through a nozzle 64 may
engage the formation 52 with sufficient energy to effect one or
more properties of the formation 52.
[0058] A portion of the formation 52 ahead of the impactor 100
substantially in the direction of impactor travel T may be altered
such as by micro-fracturing and/or thermal alteration due to the
impact energy. In such occurrence, the structurally altered zone Z
may include an altered zone depth D. An example of a structurally
altered zone Z is a compressive zone Z1, which may be a zone in the
formation 52 compressed by the impactor 100. The compressive zone
Z1 may have a length L1, but is not limited to any specific shape
or size. The compressive zone Z1 may be thermally, altered due to
impact energy.
[0059] An additional example of a structurally altered zone 102
near a point of impaction may be a zone of micro-fractures Z2. The
structurally altered zone Z may be broken or otherwise altered due
to the impactor 100 and/or a drill bit 60, such as by crushing,
fracturing, or micro-fracturing.
[0060] FIG. 2 also illustrates an impactor 100 implanted into a
formation 52 and having created an excavation E wherein material
has been ejected from or crushed beneath the impactor 100. Thereby
the excavation E may be created, which as illustrated in FIG. 3 may
generally conform to the shape of the impactor 100.
[0061] FIGS. 3 and 4 illustrate excavations E where the size of the
excavation may be larger than the size of the impactor 100. In FIG.
2, the impactor 100 is shown as impacted into the formation 52
yielding an excavation depth D.
[0062] An additional theory for impaction mechanics in cutting a
formation 52 may postulate that certain formations 52 may be highly
fractured or broken up by impactor energy. FIG. 4 illustrates an
interaction between an impactor 100 and a formation 52. A plurality
of fractures F and micro-fractures MF may be created in the
formation 52 by impact energy.
[0063] An impactor 100 may penetrate a small distance into the
formation 52 and cause the displaced or structurally altered
formation 52 to "splay out" or be reduced to small enough particles
for the particles to be removed or washed away by hydraulic action.
Hydraulic particle removal may depend at least partially upon
available hydraulic horsepower and at least partially upon particle
wet-ability and viscosity. Such formation deformation may be a
basis for fatigue failure of a portion of the formation by
"impactor contact," as the plurality of solid material impactors
100 may displace formation material back and forth.
[0064] Each nozzle 64 may be selected to provide a desired
circulation fluid circulation rate, hydraulic horsepower
substantially at the nozzle 64, and/or impactor energy or velocity
when exiting the nozzle 64. Each nozzle 64 may be selected as a
function of at least one of (a) an expenditure of a selected range
of hydraulic horsepower across the one or more nozzles 64, (b) a
selected range of circulation fluid velocities exiting the one or
more nozzles 64, and (c) a selected range of solid material
impactor 100 velocities exiting the one or more nozzles 64.
[0065] One or more controllable variables or parameters may be
altered, including at least one of: (a) rate of impactor 100
introduction into the circulation fluid, (b) impactor 100 size, (c)
impactor 100 velocity, (d) drill bit nozzle 64 selection, (e) the
selected circulation rate of the circulation fluid, (f) the
selected pump pressure, and (g) any of the monitored excavation
parameters.
[0066] To alter the rate of impactors 100 engaging the formation
52, the rate of impactor 100 introduction into the circulation
fluid may be altered. The circulation fluid circulation rate may
also be altered independent from the rate of impactor 100
introduction. Thereby, the concentration of impactors 100 in the
circulation fluid may be adjusted separate from the fluid
circulation rate. Introducing a plurality of solid material
impactors 100 into the circulation fluid may be a function of
impactor 100 size, circulation fluid rate, nozzle rotational speed,
wellbore 70 size, and a selected impactor 100 engagement rate with
the formation 52. The impactors 100 may also be introduced into the
circulation fluid intermittently during the excavation operation.
The rate of impactor 100 introduction relative to the rate of
circulation fluid circulation may also be adjusted or interrupted
as desired.
[0067] The plurality of solid material impactors 100 may be
introduced into the circulation fluid at a selected introduction
rate and/or concentration to circulate the plurality of solid
material impactors 100 with the circulation fluid through the
nozzle 64. The selected circulation rate and/or pump pressure, and
nozzle selection may be sufficient to expend a desired portion of
energy or hydraulic horsepower in each of the circulation fluid and
the impactors 100.
[0068] An example of an operative excavation system 1 may comprise
a bit 60 with an 81/2 inch bit diameter. The solid material
impactors 100 may be introduced into the circulation fluid at a
rate of 12 gallons per minute. The circulation fluid containing the
solid material impactors may be circulated through the bit 60 at a
rate of 462 gallons per minute. In one embodiment, substantial
portion by weight of the solid material impactors may have an
average mean diameter of between about 0.05'' to about 0.15, in
another embodiment impactor average diameter is about 0.075'' to
about 0.125'', in another embodiment impactor average diameter is
about 0.078'' in another embodiment impactor average diameter is
about 0.100''. The following parameters will result in
approximately a 27 feet per hour penetration rate into Sierra White
Granite. In this example, the excavation system may produce 1413
solid material impactors 100 per cubic inch with approximately 3.9
million impacts per minute against the formation 52. On average,
0.00007822 cubic inches of the formation 52 are removed per
impactor 100 impact. The resulting exit velocity of a substantial
portion of the impactors 100 from each of the nozzles 64 would
average 495.5 feet per second. The kinetic energy of a substantial
portion by weight of the solid material impacts 100 would be
approximately 1.14 Ft Lbs., thus satisfying the mass-velocity
relationship described above.
[0069] Another example of an operative excavation system 1 may
comprise a bit 60 with an 81/2 inch bit diameter. The solid
material impactors 100 may be introduced into the circulation fluid
at a rate of 12 gallons per minute. The circulation fluid
containing the solid material impactors may be circulated through
the nozzle 64 at a rate of 462 gallons per minute. A substantial
portion by weight of the solid material impactors may have an
average mean diameter of 0.075''. The following parameters will
result in approximately a 35 feet per hour penetration rate into
Sierra White Granite. In this example, the excavation system 1 may
produce 3350 solid material impactors 100 per cubic inch with
approximately 9.3 million impacts per minute against the formation
52. On average, 0.0000428 cubic inches of the formation 52 are
removed per impactor 100 impact. The resulting exit velocity of a
substantial portion of the impactors 100 from each of the nozzles
64 would average 495.5 feet per second. The kinetic energy of a
substantial portion by weight of the solid material impacts 100
would be approximately 0.240 Ft Lbs., thus satisfying the
mass-velocity relationship described above.
[0070] In addition to impacting the formation with the impactors
100, the bit 60 may be rotated while circulating the circulation
fluid and engaging the plurality of solid material impactors 100
substantially continuously or selectively intermittently. The
nozzle 64 may also be oriented to cause the solid material
impactors 100 to engage the formation 52 with a radially outer
portion of the bottom hole surface 66. Thereby, as the drill bit 60
is rotated, the impactors 100, in the bottom hole surface 66 ahead
of the bit 60, may create one or more circumferential kerfs. The
drill bit 60 may thereby generate formation cuttings more
efficiently due to reduced stress in the surface 66 being
excavated, due to the one or more substantially circumferential
kerfs in the surface 66.
[0071] The excavation system 1 may also include inputting pulses of
energy in the fluid system sufficient to impart a portion of the
input energy in an impactor 100. The impactor 100 may thereby
engage the formation 52 with sufficient energy to achieve a
structurally altered zone Z. Pulsing of the pressure of the
circulation fluid in the pipe string 55, near the nozzle 64 also
may enhance the ability of the circulation fluid to generate
cuttings subsequent to impactor 100 engagement with the formation
52.
[0072] Each combination of formation type, bore hole size, bore
hole depth, available weight on bit, bit rotational speed, pump
rate, hydrostatic balance, circulation fluid rheology, bit type,
and tooth/cutter dimensions may create many combinations of optimum
impactor presence or concentration, and impactor energy
requirements. The methods and systems of this disclosure facilitate
adjusting impactor size, mass, introduction rate, circulation fluid
rate and/or pump pressure, and other adjustable or controllable
variables to determine and maintain an optimum combination of
variables. The methods and systems of this disclosure also may be
coupled with select bit nozzles, downhole tools, and fluid
circulating and processing equipment to effect many variations in
which to optimize rate of penetration.
[0073] FIG. 5 shows an alternate embodiment of the drill bit 60
(FIG. 1) and is referred to, in general, by the reference numeral
110 and which is located at the bottom of a well bore 120 and
attached to a drill string 130. The drill bit 110 acts upon a
bottom surface 122 of the well bore 120. The drill string 130 has a
central passage 132 that supplies drilling fluids to the drill bit
110 as shown by the arrow A.sub.1. The drill bit 110 uses the
drilling fluids and solid material impactors 100 when acting upon
the bottom surface 122 of the well bore 120. The drilling fluids
then exit the well bore 120 through a well bore annulus 124 between
the drill string 130 and the inner wall 126 of the well bore 120.
Particles of the bottom surface 122 removed by the drill bit 110
exit the well bore 120 with the drilling fluid through the well
bore annulus 124 as shown by the arrow A.sub.2. The drill bit 110
creates a rock ring 142 at the bottom surface 122 of the well bore
120.
[0074] Referring now to FIG. 6, a top view of the rock ring 124
formed by the drill bit 110 is illustrated. An excavated interior
cavity 144 is worn away by an interior portion of the drill bit 110
and the exterior cavity 146 and inner wall 126 of the well bore 120
are worn away by an exterior portion of the drill bit 110. The rock
ring 142 possesses hoop strength, which holds the rock ring 142
together and resists breakage. The hoop strength of the rock ring
142 is typically much less than the strength of the bottom surface
122 or the inner wall 126 of the well bore 120, thereby making the
drilling of the bottom surface 122 less demanding on the drill bit
110. By applying a compressive load and a side load, shown with
arrows 141, on the rock ring 142, the drill bit 110 causes the rock
ring 142 to fracture. The drilling fluid 140 then washes the
residual pieces of the rock ring 142 back up to the surface through
the well bore annulus 124.
[0075] FIG. 10 schematically represents an example of a drilling
system 320 employing a concrete pump 322 as described herein. The
concrete pump 322 pressurizes a slurry of fluid and impactors that
is then discharged to a slurry discharge line 324. The slurry
discharge line 324 terminates with a pressurized drilling fluid
line 330 at an injection point 325. Drilling fluid pressurized by a
pressure source 328 flows from the pressure source 328 through the
pressurized drilling fluid line 330 and to the injection point 325,
where the impactor and fluid slurry is injected therein. The
concrete pump 322 pressurizes the slurry to a set pressure of
sufficient magnitude ensure the impactor fluid slurry is injectable
into the pressurized drilling fluid line 330. The set pressure may
be at a value where injecting the impactor fluid slurry into the
pressurized drilling fluid line 330 is by pressure differential and
without an eductor. As will be discussed in more detail below, the
impactor and fluid slurry pressure is maintained at a relatively
constant value in the slurry discharge line 324 thereby preventing
pressurized drilling fluid ingress from the pressurized drilling
fluid line 330 into the slurry discharge line 324. An optional one
way valve 326 is illustrated in the slurry discharge line 324 and
represents one manner of preventing such ingress. Examples of one
way valves 326 include check valves, float valves, and motor
operated valves.
[0076] A combined stream of impactor and fluid slurry and
pressurized drilling fluid flows in a drilling system fluid feed
line 327 collected downstream of the injection point 325. The
combined stream is fed to a drill string 334 driven by one of a
swivel 332 or a top drive disposed over a wellbore 338. The drill
string 334 is used to create the wellbore 338 through a
subterranean formation 340. As previously described, the combined
flow of impactor fluid slurry and drilling fluid is injected into
the drill string 334 where it is directed to a drill bit 336
attached to the lower terminal end of the drill string 334. The
fluid exits the drill bit 336 through nozzles (not shown), an
upward stream 342 of fluid, impactors, and formation cuttings flows
from the bit 336 and through an annulus 335 formed between the
drill string 334 and wellbore 338 walls. The upward flow 342 is
collected at surface where the impactors can be reclaimed for
future use.
[0077] The system described herein is not limited to injecting a
slurry of impactors and fluid into a drilling fluid line, but can
also be used to inject other fluids or solids into a stream being
directed within a wellbore. In one example of use, a pump as
described herein pressurizes a stream having a proppant that is
directed downhole. The downhole operation involving the proppant
may include a facing process that fractures subterranean formations
for enhancing hydrocarbon production from within the formation.
Other fluids considered for use with the pumping system include
acidizing fluids, brines, alcohols, and other wellbore treating
substances.
[0078] In an exemplary embodiment, as illustrated in FIG. 7, a
valve system 800 is illustrated which is adapted to maintain a
constant pressure during cycling between the intake and discharge
steps of the first and second pump cylinders of a concrete pump.
Valve system 800 is adapted to alternate between two feed sources,
cylinders 802 and 804 respectively. As illustrated in FIG. 7, the
first cylinder 802 is shown as the discharge cylinder and second
cylinder 804 is shown as the filling cylinder. The valve body 820
includes an inlet 810 which can be rotated between the first and
second cylinder outlets, 805 and 807 respectively. In a first
position, the valve inlet 810 is aligned with the outlet 805 of the
first pump cylinder 802 and the corresponding port 806. The
concrete, slurry, or other material is pumped out of cylinder 802,
though the first cylinder outlet 805, and into port 806 in the
sequencing valve. The flow paths through which the material enters
through inlet 810 and exits the valve body 820 are not required to
be in the same plane to function properly and may take multiple
forms by one skilled in the art of material flow. The material is
pumped into the valve, and exits through the outlet 814. As the
material is pumped out of the first cylinder 802, material is
simultaneously introduced into the second cylinder 804. Upon
completion of the pumping of the contents of the first cylinder
802, the valve inlet 810 rotates to facilitate the discharge of the
material from the second cylinder 804 that was being loaded while
the first cylinder 802 was discharging. After the contents of the
second cylinder 804 have been pumped through the valve system 800,
the valve inlet 810 rotates to again align with the first cylinder
802 and the process is repeated.
[0079] In an exemplary embodiment, the pump is a Schwing BP8800
concrete pump having which includes Rock Valve, a Big Rock Valve,
or a similar functioning valve. In certain exemplary embodiments,
the concrete pump may be modified so that the output pressure of
the cylinder is approximately the same as the piston pressure. Such
modifications may include, but are not limited to, decreasing the
area of the cylinder, increasing the operating pressure, and/or
increasing the piston size. In certain embodiments, the output
horsepower of the engine associated with the concrete pump may be
increased. In certain other embodiments, the rock valve may be
modified to include wings or shoulder (as described herein) to
maintain a more constant output pressure and reduce a decrease in
pressure between intake and discharge steps during pumping with the
concrete pump. In certain embodiments, a check valve may also be
employed with the rock valve and the wings/shoulders employed at
the inlet of the valve. In certain other embodiments, a pressure
compensation device may be employed with the pump.
[0080] In an exemplary embodiment, the slurry feed of solid
material impactors and drilling fluid to the pump contains from
50-90% by volume of solid material impactors and from 10-50% by
volume of drilling fluids. In another exemplary embodiment, the
slurry feed to the pump contains from 55-75% by volume of solid
material impactors and from 25-45% by volume of drilling fluids. In
another exemplary embodiment, the slurry feed to the pump contains
from 58-65% by volume of solid material impactors and from 35-42%
by volume of drilling fluids. In another exemplary embodiment, the
slurry feed to the pump contains approximately 62% by volume of
weight solid material impactors and approximately 38% by volume of
drilling fluids.
[0081] In an exemplary embodiment, the feed rate of impactors to
the cement pump is at least about 2 gal/min. In another exemplary
embodiment, the feed rate of impactors to the cement pump is at
least about 10 gal/min. In yet another exemplary embodiment, the
feed rate of impactors to the cement pump is at least about 15
gal/min. In yet another exemplary embodiment, the feed rate of
impactors to the cement pump is at least about 20 gal/min. In yet
another exemplary embodiment, the feed rate of impactors to the
cement pump is at least about 30 gal/min. In yet another exemplary
embodiment, the feed rate of impactors to the cement pump is at
least about 40 gal/min. In yet another exemplary embodiment, the
feed rate of impactors to the cement pump is at least about 50
gal/min. Optionally, the concrete pump cylinder angle with respect
to horizontal may be adjusted to control the impactor feed
rated.
[0082] In an exemplary experimental embodiment, a test was
conducted using a Schwing BP8800 concrete pump for injection of a
slurry of solid material impactors. The concrete pump was operated
at 2,100 RPM, a piston pressure of 4,900 psi, a high cylinder
pressure of 3,900 psi and a low cylinder pressure of 1,700 psi. The
concrete pump was able to inject the slurry of solid material
impactors at a rate of up to 17.0 gpm at a standpipe pressure of
greater than 3,000 psi.
[0083] The pressure on port 814 shown in FIG. 7 remains relatively
constant because the port 814 is fluidically coupled with a closed
system. This closed system generally consists of cylinder 802
during its discharge cycle, cylinder 804 during its discharge
stroke or the valve body during orbit between cylinders. It is
understood that the pressure can be maintained with more or fewer
components or by incorporating any number of pressure regulating
devices or manipulating the cycle timing.
[0084] In an exemplary embodiment, a valve is described for use
with a concrete pump having a single material cylinder. The valve
can be adapted to maintain pressure in the cylinder between intake
and discharge cycles. In an exemplary embodiment, the valve
includes a wing or shoulder, similar to the wings or shoulders 908a
and 908b shown in FIGS. 5a and 8b, positioned on either side of the
inlet which is adapted to cover the cylinder and prevent a loss of
pressure, thereby achieving constant pressure on the discharge
outlet of the valve. This improvement may be incorporated to any
conventional concrete pump, such as for example, the concrete pumps
produced by, but not limited to, Schwing Bioset, Schwing, and
Putzmeister. The following are incorporated herein by reference:
Schwing America Inc, Electrical Schematic #10200527, BP 8800,
serial number 108242; Schwing Operating Instructions BP 880 Article
No. 10202001; Schwing America Inc, Parts List BP 880 CE Trailer
Pump 108242; Schwing America Inc, Hydraulic Fittings High Pressure
Hoses, Document # 699000, Rev. May 17, 2002; and Schwing America
Inc., Service Repair Instructions for The "Rock" Valve, Document
#799000, Rev. May 18, 2002. Selected pages of one or more of the
above documents are attached herewith as Appendix A. The entire
contents of the attached Appendix A is incorporated by reference
herein.
[0085] In an exemplary embodiment, as illustrated in FIGS. 8A and
8B, another valve 900 is illustrated which is similarly adapted to
maintain a constant pressure during cycling between the intake and
discharge steps of a first and second cylinder. FIG. 5A is a
sectional view of the inlet of the valve 900. The valve consists of
a body 902 connected to a shaft 904, on which the body swings
between the first and second cylinder outlets (shown with dashed
lines as 910 and 912). The inlet 906 to the valve 900 is adapted to
cycle between the outlet 910 of the first cylinder and the outlet
912 of the second cylinder. The valve may include a shoulder
portion (shown with the dashed line as 908a and 908b) which extends
outward from the portion of the valve body 900 surrounding the
valve inlet 906. The shoulder portions 908a and 908b may be
fashioned in different shapes and sizes to achieve the result of
preventing a loss of pressure during cycling of the valve.
[0086] FIG. 8B is a sectional view of the outlet of the valve 900.
The outlet 914 can be a variety of different shapes, as shown here
the outlet has a kidney shape, allowing for simplified alignment
with the outlet 916. As can been seen by the in the two figures,
the cylinder outlets 910 and 912 not collinear with the valve
outlet 916.
[0087] In an exemplary embodiment, as illustrated in FIG. 9, the
injection system 670 may include a concrete pump 566 which includes
sequencing valve (not shown) selected from either a Rock Valve or a
Big Rock Valve, produced by Schwing America, Inc., or a like valve.
The injection system 670 may further include a diversion valve 672
connected to the pump 566 by pipe 570. The diversion valve 672
serves to delay the injection of the impactors 100 until the system
is prepared to go "on-line." Diversion valve 672 diverts the steam
of impactors via line 674 to the hopper 506, where the impactors
may be resupplied to pump 566 via line 568. Optionally, line 674
may supply a stream of impactors to a particle processing step.
Thus, in one exemplary embodiment, the injection system is operated
and a continuous stream of the impactors is held in a continuous
loop, wherein the impactors are supplied to the pump, discharge
from the pump and are diverted to the hopper or processing step,
and resupplied to the pump. Once the operator is ready to bring the
injection system 670 "on-line", the diversion valve may be operated
to supply impactors to the standpipe 504. In an exemplary
embodiment, a check valve is employed between the pump and the
standpipe to maintain a steady pressure in the standpipe. The
injection system 670, by allowing the recirculation of impactors
while "off line," will allow the concrete pump 566, or other pump,
to be run independently of the drilling rig and be brought on line
quickly. Another benefit of the injection system 670 is that the
impactors, which will settle to the bottom of pipe 570 are
constantly moving to prevent the impactors from settling and
plugging wetted components.
[0088] In an exemplary embodiment, the pump 566 includes one or
more pumps such as for example, one or more solids pumps, cavity
pumps, positive displacement pumps, progressive cavity pumps, auger
pumps, Moineau pumps and/or any combination thereof. In several
exemplary embodiments, one or more of the pumps that comprise the
pump 566 are configured to pump dry or almost-dry solid material
impactors. In several exemplary embodiments, one or more of the
pumps that comprise the pump 566 are similar to pumps used to pump
concrete, and/or to pump slurries. Examples of these types of pumps
are manufactured by a variety of manufacturers, including but not
limited to, Schwing Bioset, Schwing, and Putzmeister.
[0089] In an exemplary embodiment, impactors may be supplied to the
concrete pump via means of a volumetric feeder. In another
exemplary embodiment, impactors may be supplied to the concrete
pump via means of a hopper. In another exemplary embodiment,
impactors which are recovered from the wellbore are processed to
remove drill cuttings, small particulate materials, and drilling
fluids and may be then resupplied to the concrete pump 566.
[0090] In an exemplary embodiment, a particle injection system,
which may include concrete pump 566, may also include one or more
abrasion resistant or longer-wear components, such as for example,
non-hardened pipe, heat-treated pipe, abrasion resistant single
wall pipe, and twin wall pipe, each of which may optionally include
chrome carbide insert ends or chrome carbide liners. Similarly, the
particle injection system, which may include the concrete pump 566,
may also include one or more ceramic, cast manganese or cast steel
hardened elbow or bends having chrome carbide ends and/or chrome
carbide lining. Exemplary particle injection systems which employ
concrete pumps for the injection of solid material impactors for
drilling purposes, are particularly suited for the use of
reinforced elbows, joints, pipes and other components. Exemplary
abrasion resistant parts suitable for use for the present
application include those manufactured by Schwing America, Inc.,
Schwing Bioset, Inc., and Construction Forms, Inc. of Port
Washington, Wis.
[0091] In other exemplary embodiments, a wear ring can be included
at the interface between piping components, such as between the
standpipe and the elbow. Preferably, the wear ring is manufactured
from a highly wear and abrasion resistant material. In certain
exemplary embodiments, the material has a higher hardness than the
particulate matter. In certain embodiments, the wear ring is a
wearable surface which can resist chipping or cracking in a highly
abrasive environments.
[0092] In an exemplary embodiment, the pump 566 may be connected to
one or more hydraulic or manual diversion or shut-off valves which
are designed for concrete pumping applications. In another
exemplary embodiment, the pump 566 may be connected to one or more
diversion or shut-off valves which are designed for high pressure
applications. In another exemplary embodiment, the pump 566 may be
connected to one or more diversion or shut-off valves which are
designed for pumping highly abrasive slurries.
[0093] In exemplary embodiments, the concrete or slurry pump
discharge pressure may range from about 1500 pounds per square inch
and in excess of about 6000 pounds per square inch, from about 1500
pounds per square inch to about 2500 pounds per square inch, from
about 2500 pounds per square inch to about 6000 pounds per square
inch, and all values between about 1500 pounds per square inch and
about 6000 pounds per square inch. Higher pressures likely lead to
increased drilling capabilities and greater penetration of
impactors. Accordingly, in an optional embodiment, pump discharge
pressures may range from about 1000 pounds per square inch to about
10,000 pounds per square inch. In an exemplary embodiment, the pump
566 includes one or more concrete or slurry pumps. However, instead
of pumping concrete, the pump 566 pumps the impactors 100, and any
associated fluids, during the operation of the particle injection
system, as described above.
[0094] Contact surfaces of the devices and systems disclosed
herein, such as the contacting surface of a transfer tube (also
referred to herein as a rock valve or big rock valve) may include:
steels hardened past raw material specifications, tool steels,
specialty materials such as Inconel.RTM., Stellite.RTM., titanium,
and alloys having one of nickel, silver, bronze, molybdenum, and
copper, and combinations thereof. Composites having an abrasion
resistant material and a softer filler, such as tungsten carbide,
nickel, copper, silver, alloyed metals, abrasive cloth, layered
materials and combinations thereof. Coatings applied with a spray,
fused thereon, cast, welded, brazed, burnished, or splattered.
Super abrasive materials, such as cubic boron nitride, diamond like
materials, diamond silicon carbide, aluminum oxide, and
combinations thereof. Materials harder than steel that are allied
by chemical vapor deposition technology. Elastomeric, and polymeric
materials, such as urethane, and others including filled elastomers
and polymers, including layered. Reinforced materials, including
fibers, stands, or chopped materials.
[0095] In an exemplary embodiment, the pump 566 includes one or
more concrete or slurry pumps manufactured by Schwing America Inc.
of St. Paul, Minn. or Schwing Bioset, Inc. of Somerset, Wis. In an
exemplary embodiment, the pump 566 includes one or more concrete
pumps manufactured by Schwing America, Inc. of St. Paul, Minn., and
at least one of the one or more concrete pumps includes a Rock
Valve sequencing valve and/or a Big Rock Valve sequencing valve,
which are manufactured by Schwing America, Inc. of St. Paul, Minn.
Instead of pumping concrete, however, the pump 566 pumps the solid
material impactors 100, and any associated fluids, during the
operation of the particle injection system, as described above. In
some exemplary embodiments, the concrete pump 566 can be used to
pump dry particulate materials, and in other exemplary embodiments,
the concrete pump 566 can be used to pump a slurry which may
include particulate materials. In certain exemplary embodiments,
the concrete pump 566 is used to introduce a particulate slurry
into a wellbore.
[0096] Other pump manufacturers producing concrete or slurry pumps
which may also be used to supply particulate material according to
the present application include, but are not limited to, one or
more of the pumps manufactured by any of the following
manufactures: Putzmeister AG (Germany), Putzmeister America, Inc.
(Sturtevant, Wis.); Multiquip/Mayco (Carson, Calif.); Reed Concrete
Pumps (Chino, Calif.); Allentown Equipment (Allentown, Pa.) and
Olin Engineering (CA). It is understood that other concrete and
slurry pumps manufactured by other manufacturers not listed herein
may also be used to pump particulate materials and slurries which
include particulate materials. Exemplary concrete pumps may include
one or more sequenced material cylinder for pumping particulate
materials. Other exemplary pumps include any pump capable of taking
a slurry at atmospheric pressure and discharging the slurry at a
higher pressure. In certain exemplary embodiments, the cylinders
may be hydraulically driven.
[0097] In an exemplary embodiment, the pump 566 is a positive
displacement concrete pump which includes a sequencing valve having
a transfer tube and at least one material cylinder. The sequencing
valve may be a Rock Valve or a Big Rock Valve, produced by Schwing
America, or a Rock Valve produced by Schwing Bioset, Inc., or a
like sequencing valve. Other valves may also be employed to
sequence between the intake and discharge of materials, such as for
example, an S-tube valve, a C-tube valve, ball valves, or gate
valves.
[0098] A perspective partially exploded view of a portion of an
example of a concrete pump 322 is depicted in FIG. 11. The concrete
pump 322 illustrated comprises a housing 344 shown with a
semi-circular cross section, however enclosures having other shapes
can also be used. To illustrate the pump 322 internal components,
an upper enclosure is not shown in this illustration. It is well
within the capabilities of those skilled in the art to implement a
proper upper enclosure. The housing is portrayed having therein a
first cylinder 346 and second cylinder 348, the cylinders (346,
348) both aligned substantially parallel with the elongate length
of the concrete pump 322. A substantially planar forward housing
345 is provided within the housing 344 transverse to the cylinders
(346, 348) and defines a terminal end of the cylinders (346, 348).
A rearward housing 349, aligned substantially parallel with the
forward housing 345 comprises a housing 344 end opposite the
forward housing 345. For the purposes of discussion herein, the
term "aft" refers to a direction towards the rearward housing 349,
and forward refers to a direction towards the forward housing 345.
A first opening 354 is formed through the forward housing 345 that
registers with the first cylinder 346. A second opening 356 also
formed through the forward housing 345 registers with the second
cylinder 348. A first piston 350 is illustrated in dashed outline
within the first cylinder 348 shown having a connecting rod 351
affixed to its aft end. A second piston 352 is shown, also in
dashed outline, in the second cylinder 348 having a connecting rod
353 affixed to its aft end.
[0099] The housing 344 sides and lower portion extend forward past
the forward housing wall 345 and have a flanged surface 355 formed
on the forward terminal end. An end cover 360 is shown in exploded
view away from the housing 344, when the concrete pump 322 is
assembled the end cover 360 mates onto the flanged surface 355. A
mixing feed chamber 358 is defined between the forward housing wall
345 and end cover 360 and bounded on its lower end by the housing
344 sides and lower portion that extend past the forward housing
wall 345. A pump discharge line 362 connected to the end cover 360
extends forward from the concrete pump 322 and is in fluid
communication with one of the openings (354, 356) by a passage 361
formed through the end cover 360.
[0100] In one example of concrete pump 322 operation, a slurry of
impactors 359 and fluid 357 are fed into the mixing feed chamber
358. The mixing feed chamber 358 is typically at approximately
ambient pressure. The pistons (350, 352) are reciprocated within
the cylinders (346, 348) and draw the slurry into a cylinder (346,
348) when the associated piston is moving in an aft direction
(suction stroke) and then pressurize the slurry drawn into the
cylinder when the piston is moved forward (pressurization or
discharge stroke). As described below, a valve system selectively
communicates each opening (354, 356) with the mixing feed chamber
358 when the respective piston (350, 352) is reciprocating aft. The
valve then selectively seals the respective cylinder (346, 348)
from the mixing feed chamber 358 when the associated piston (350,
352) changes its stroke from aft to forward and fluidly couples the
opening (354, 356) with the pump discharge 361. When the piston
(350, 352) moves forward in the cylinder (346, 348) impactor fluid
slurry in the cylinder (346, 348) is pressurized and discharged
from the pump 322 through the pump discharge 361. In the example
shown in FIG. 11, arrow A.sub.1 demonstrates the piston 350 is
moving in the aft direction and draws impactor fluid slurry into
the cylinder 346 via the opening 354. Similarly, the piston 356 is
moving forward as depicted by arrow A.sub.2 and pressurizing
impactor fluid slurry in the cylinder 348. The pressurized impactor
fluid slurry is discharged through the opening 356 to the pump
discharge 361 through a selector valve (not shown). Optionally, an
impactor fluid slurry can be injected into the cylinders (346, 348)
through a passage (not shown) formed through the pistons (350, 352)
and piston connection rods (351, 353). Power for reciprocating the
pistons (350, 352) is provided through the piston connection rods
(351, 353) and may be from hydraulic power, mechanical power, or
electrical power. Yet further optionally, a perturbation device may
be included within the mixing feed chamber 358 for mixing the
impactors and fluid therein. Examples include mechanical agitators
(such as an inserted mixer or a blade on the transfer tube) and
nozzles ejecting a fluid stream directed at or within the impactor
fluid slurry, the fluid can be a gas or liquid.
[0101] Referring again to FIG. 11, an optional chamfer 363 is
illustrated extending from the piston 351 forward end. Having a
tapered or beveled cross section, the chamfer 363 may direct
impactors 359 and other particles away from the gap between the
piston 351 outer periphery and cylinder 346 inner circumference to
prevent trapped particles in the gap that may damage either the
piston 351 or cylinder 346. The chamfer 363 may be on a portion of
or the entire piston 351 circumference.
[0102] FIGS. 12a-12c illustrate an embodiment of a selector valve
assembly 364 that selectively seals the openings (354, 356) of the
cylinders (346, 348) from the feed mixing chamber 358 and
selectively communicates the openings (354, 356) of the cylinders
(346, 348) with the slurry discharge line 324 (FIG. 10). In the
embodiment of FIGS. 12a-12c the selector valve assembly 364
comprises a first reciprocating valve 372 associated with the first
opening 354 and a second reciprocating valve 376 associated with
the second opening 356. The selector valve assembly 364 uses a
modified end cover 360a having a first discharge 368 and a second
discharge 370. The first and second discharge (368, 370) both
connect to the slurry discharge line 324 (FIG. 10). Discharge flow
passages (374, 378) are formed through each body (380, 381) and are
registerable with respective openings (354, 356) and the discharge
flow passages (374, 378) to provide fluid communication
therebetween.
[0103] As seen in an overhead view in FIG. 12b, each valve (372,
376) comprises a body (380, 381) having on its upper end a sloped
inlet ramp (373, 377) having an opening in communication with the
suction opening of the cylinder, the embodiment shown comprises a
curved lower surface. As shown in FIG. 12b, the first reciprocating
valve 372 is positioned to allow communication between the mixing
feed chamber 358 and the first opening 354. The inlet ramp 373 on
the body 380 is aligned with the opening 354 and configured to
receive impactor fluid slurry therein and direct it into the
opening 354. Arrow A.sub.S represents impactor fluid slurry flow
over the inlet ramp 373 and into the opening 354. Coupling
attachments (375, 379) shown in FIGS. 12a and 12c are provided on
the lower end of each body (380, 381) for connecting the valves
(372, 376) to an actuation source for reciprocatingly actuating the
valves (372, 376). In the embodiment of FIGS. 12a-12c the valves
(372, 376) vertically shuttle between a suction position
(communicating the openings (354, 356) with the mixing feed chamber
358) and a discharge position (communicating the openings (354,
356) with the discharge flow passages (374, 378) and the first and
second discharges (368, 370). The shuttling may be alternating and
180.degree. out of phase, i.e. one valve (372, 376) in the suction
position and the other in the discharge. Optionally the valves
(372, 376) may be synchronous, i.e. operating at the same position
simultaneously, or out of phase by less than 180.degree.. To
facilitate the timing issues when the valves (372, 376) are out of
phase by less than 180.degree., the piston (348, 350) stroke
velocity may be adjusted so their suction stroke time differs from
the pressurization stroke time. This adjustment creates a piston
(350, 352) sequence where both can be discharging at the same time,
although at different portions of the discharge stroke, but
generally not in the suction mode at the same time. Accordingly,
the valve operation sequence provides a method to avoid pressure
communication between the mixing feed chamber 358 and the discharge
line 361. Optionally, the bodies (380, 381) can be affixed to one
another or combined in a uni-body assembly. Moreover, the
reciprocating action of the bodies (380, 381) can be in a
non-vertical alignment. The mixing feed chamber and other
components may be combined or eliminated.
[0104] FIGS. 13a-13h illustrate another embodiment of a selector
valve assembly 364a in various operational modes. FIGS. 13a, c, e,
g are frontal views and FIGS. 13 b, d, f, h are perspective views.
In this embodiment the selector valve assembly 364a comprises a
first and a second transfer tube (382, 384) both transversely
disposed in the mixing feed chamber 358. The transfer tubes (382,
384) are rotatingly coupled to pivot pins (383, 385) that are
affixed to the end cover 360, the forward housing wall 345, or
both. The transfer tubes (382, 384) are annular members having an
entrance selectively registerable with respective first and second
openings (354, 356). Each transfer tube (382, 384) has an exit on
an end opposite the entrance respectively in fluid communication
with the first and second discharges (368, 370) formed through the
end cover 360. Pivoting the transfer tubes (382, 384) with respect
to the pivot pins (383, 385) laterally orbits the transfer tubes
(382, 384) along a curved path on the forward surface of the
forward housing wall 345. Selective lateral orbiting registers the
transfer tubes (382, 384) with their respective openings (354, 356)
thereby fluidly communicating the openings (354, 356) with
respective discharges (368, 370) through the transfer tube (382,
384). In FIGS. 13a-13h the end cover 360 is illustrated translucent
to better demonstrate features of the selector valve assembly 364a.
The outer periphery of the transfer tubes (382, 384) is
substantially circular at its entrance proximate to the forward
housing wall 345 and expands to a generally oval configuration at
its exit proximate to the end cover 360. The elongate length of the
oval exit is greater than the diameter of the circular
entrance.
[0105] With reference now to FIGS. 13a and 13b, the first transfer
tube 382 is pivoted into a suction configuration with its entrance
out of registration with the opening 354. The pivoting rotational
movement is illustrated by curved arrow P.sub.S. The transfer tube
382 entrance seals against the forward facing surface of the
forward housing wall 345 and thus is not in pressure communication
with the mixing feed chamber 358. Without the transfer tube 382
sealing and isolating the opening 354 from the mixing feed chamber
358, the opening 354 is in communication with the mixing feed
chamber 358. Combining the communication between the chamber 358
and the opening 354 with a suction stroke on the piston 350 (FIG.
11) draws impactor fluid slurry into the cylinder 346 as
illustrated by arrow A.sub.IN.
[0106] Also in FIGS. 13a and 13b, the second transfer tube 384 is
shown pivoted about its pivot pin 385 having its entrance aligned
with the opening 356. This alignment combined with a discharge
stroke of the piston 352 (FIG. 11) discharges impactor fluid slurry
through the transfer tube 384 and discharge 370 as illustrated by
arrow A.sub.OUT. In FIGS. 13c and 13d the first transfer tube 382
has been pivoted (as illustrated by curved arrow P.sub.D)
registering its entrance with the opening 354. Positioning the
sealing face of the first transfer tube 382 around the opening 354
sealingly isolates the opening 354 from the mixing feed chamber
358, thereby isolating the first transfer tube 384 and discharge
370 from ambient pressure. Combining this alignment with the piston
350 in a discharge stroke discharges impactor fluid slurry through
the transfer tube 382 and the first discharge 368. In FIGS. 13c and
13d, pressurized impactor fluid slurry may be discharged from both
the first and second transfer tubes (382, 384) for a period of
time. As described above, one way to accomplish this is by having a
suction stroke time different from the discharge stroke time. The
pressurized impactor fluid slurry discharged from the first and
second discharge (368, 370) is directable to the slurry discharge
line 324 (FIG. 10). In one example of use, the first and second
piston advance in sequence to provide a combined forward velocity
that is near constant, resulting in a near constant pressure and
impactor discharge rate.
[0107] Pivoting the transfer tubes (382, 384) about their
respective pivot pins (383, 385) can be accomplished via hydraulic
power, electrical power, or mechanical means. It is within the
capabilities of those skilled in the art to apply a pivoting force
synchronized as described herein. As illustrated in FIGS. 13a and
13c, the outwardly flared exit of the first and second transfer
tubes (382, 384) remains in fluid communication with the respective
discharge (368, 370) during transfer tube (382, 384) pivoting.
[0108] FIGS. 13e and 13f represent the first transfer tube 382 and
associated cylinder 346 and piston 350 in a discharge stroke
whereas the second transfer tube 384 is pivoted into a suction mode
(as illustrated by curved arrow P.sub.S) allowing communication
between the mixing feed chamber 358 and the entrance 356. Arrows
A.sub.IN and A.sub.OUT respectively represent impactor fluid slurry
suction into the opening 356 and pressurized impactor slurry
discharge from the first discharge 368. Pivoting the second
transfer tube 384 into alignment with the entrance 356 (as
illustrated by curved arrow P.sub.D) is depicted in FIGS. 13g and
13h. Pressurized impactor fluid slurry discharge is shown by arrow
A.sub.OUT. An example of a transfer tube suitable for use as
disclosed herein is a "rock valve" obtainable from Schwing America
Inc., 5900 Centerville Road, St. Paul, Minn. 55127, 651-429-0999,
www.schwing.com.
[0109] Another example of a selector valve assembly 364b is
provided in perspective view in FIG. 14. In this embodiment, the
selector valve assembly 364b comprises a kidney shaped shroud 365,
the shroud 365 is substantially planar and disposed parallel with
the forward surface of the forward housing wall 345. An annular
transfer tube 366 extends from the forward surface of the shroud
365 and affixed to the shroud 365 in alignment with an aperture 369
formed through the shroud 365. The valve assembly 364b is
pivotingly affixed to a pivot pin 367 connected to the forward
housing wall 345 thereby providing pivoting motion of the valve
assembly 364b adjacent the forward housing wall 345. As shown the
valve assembly 364b is situated to transfer pressurized impactor
and fluid slurry from the discharge stroke of the first piston 350
and cylinder 346 via the first opening. When pivoting the assembly
364b to receive discharge slurry from the second opening 354, the
shroud 365 seals the first opening 356 from the ambient pressure
mixing feed chamber 358 before the transfer tube 366 registers with
the second opening 356 thereby sealing the transfer tube 366 from
the mixing feed chamber 358 and preventing the discharge circuit
from exposure to ambient pressure conditions.
[0110] An optional seal assembly 388 for sealing between the exit
of a transfer tube (382, 384) and the end cover 360 is shown in an
end view in FIG. 15. A representation of the transfer tube (382,
384) axis A.sub.X is provided for reference. The seal assembly 388
comprises a seal body 390, a wiper base 391, and a wiper edge 392
extending from the base 391. As shown in partial sectional view in
FIG. 16, the wiper edge 392 has a beveled cross section and extends
outward from the seal assembly 388 outer periphery. An optional
elastomer o-ring 394 is provided between the wiper base 391 and the
seal body 390 outer periphery. A representation of the transfer
tube (382, 384) axis A.sub.X is provided for reference. The wiper
edge 392 includes a planar surface on the side disposed adjacent
the end cover 360 with the bevel on the other side. When pivoting
the transfer tube (382, 384) as previously described the seal
assembly 388 may encounter impactors 347 and other solid material
on the mating surface of the end cover 360. When pivoting the
transfer tube (382, 384), in the back and forth direction
represented by the double headed arrow P.sub.M, the beveled wiper
edge 392 can scrape away solid particles. This avoids wedging
particles between the seal body 390 and the end cover 360 surface
thereby preventing damage of either the seal assembly 388 or end
cover 360 surface due to scratching or gouging by the particles. A
force generating means, such as a spring 393 is shown for
energizing the wiper base 391 against the end cover 360 and a
potentially separate sealing means between the wiper base 391 and
the transfer tube (382, 384).
[0111] An optional seal 369 coupled with an end of a transfer tube
366a is illustrated in perspective view in FIG. 17. In this
embodiment, a viscous fluid, such as a lubricant, is delivered to a
plenum 386 formed in the free end of the seal 369. Delivering a
lubricating substance through the seal provides a self
correcting/replenishing seal which may be used in circuits for
pumping low viscosity slurries and at high pressures. As shown in a
cross sectional view in FIG. 18, a lubricating fluid is delivered
to the plenum 386 via a lubricant feed line 371 connected to the
plenum 386. Lubricant flow, represented by arrow A.sub.L, passes
through the plenum 386 and into a gap 387 between the seal 369 and
the end plate 360. The lubricating fluid may be pumped from a
reservoir and charged to a high pressure. The lubricant can be
delivered to the seal during static conditions to provide motion
starting lubrication as well as a sealing function. It should be
pointed out however the seal assembly described herein is not
limited to the transfer tube or end plate, but is applicable to
other contacting surfaces.
[0112] Optionally included with a seal assembly disposed between
the transfer tube and the end cover is an anti-extrusion member.
The anti-extrusion member may circumscribe the seal assembly and be
combined with an O-ring. Yet further optionally, the backup O-rings
may be included with all sealing components for the device and
system disclosed herein.
Example 1
[0113] Impactors were circulated in the system for 75 minutes with
an impactor flow rate of about 15 gallons per minute, a hopper fill
rate of 165 to 190 gallons per minute, with a total flow rate of
360 to 370 gallons per minute, a pump discharge pressure between
1000 pounds per square inch to 2500 pounds per square inch. A
Schwing BPS800 was used for pressurizing impactor and fluid
slurry.
Example 2
[0114] Impactors were circulated in the system for 94 minutes with
an impactor flow rate of about 15 gallons per minute, a hopper fill
rate of 100 to 160 gallons per minute, with a total flow rate of
340 to 375 gallons per minute, a pump discharge pressure between
1000 pounds per square inch to 2500 pounds per square inch. A
Schwing BP8800 was used for pressurizing impactor and fluid
slurry.
[0115] It is understood that variations may be made in the
foregoing without departing from the scope of the disclosure.
[0116] Any spatial references such as, for example, "upper,"
"lower," "above," "below," "radial," "axial," "between,"
"vertical," "horizontal," "angular," "upward," "downward,"
"side-to-side," "left-to-right," "right-to-left," "top-to-bottom,"
"bottom-to-top," etc., are for the purpose of illustration only and
do not limit the specific orientation or location of the structure
described above.
[0117] As used herein, the terms "about" and "approximately" are
understood to refer to values which are within 5% of the number
being modified by the terms.
[0118] In several exemplary embodiments, one or more of the
operational steps in each embodiment may be omitted. Moreover, in
some instances, some features of the present disclosure may be
employed without a corresponding use of the other features.
Moreover, one or more of the above-described embodiments and/or
variations may be combined in whole or in part with any one or more
of the other above-described embodiments and/or variations.
[0119] Although several exemplary embodiments have been described
in detail above, the embodiments described are exemplary only and
are not limiting, and those skilled in the art will readily
appreciate that many other modifications, changes and/or
substitutions are possible in the exemplary embodiments without
materially departing from the novel teachings and advantages of the
present disclosure. Accordingly, all such modifications, changes
and/or substitutions are intended to be included within the scope
of this disclosure as defined in the following claims. In the
claims, means-plus-function clauses are intended to cover the
structures described herein as performing the recited function and
not only structural equivalents, but also equivalent
structures.
* * * * *
References