U.S. patent application number 11/433779 was filed with the patent office on 2007-11-15 for wellbore cleaning tool system and method of use.
Invention is credited to Travis Brunet, Stevie Shackelford.
Application Number | 20070261855 11/433779 |
Document ID | / |
Family ID | 38684038 |
Filed Date | 2007-11-15 |
United States Patent
Application |
20070261855 |
Kind Code |
A1 |
Brunet; Travis ; et
al. |
November 15, 2007 |
Wellbore cleaning tool system and method of use
Abstract
A wellbore cleaning tool system includes a plurality of brushes
and scrappers supported by or mounted to a casing body to clean an
interior wall of a wellbore. The cleaning tool system includes
selectively actuated high-velocity jet sprays to aid the cleaning
of the interior wall of a wellbore by enhance the loosening and
releasing of mud cake, oily residue, cement sheath, and pipe scale.
The jet sprays also aid in the cleaning operation performed by and
efficiency of the brushes and scrappers by spraying, loosening and
releasing matter (mud cake, oily residue, cement sheath, and pipe
scale) adhering to or sticking on the brushes and scrapers.
Inventors: |
Brunet; Travis; (Houma,
LA) ; Shackelford; Stevie; (Houma, LA) |
Correspondence
Address: |
RAYMOND G. AREAUX
1100 POYDRAS STREET, SUITE 2700
NEW ORLEANS
LA
70163
US
|
Family ID: |
38684038 |
Appl. No.: |
11/433779 |
Filed: |
May 12, 2006 |
Current U.S.
Class: |
166/312 ;
166/173 |
Current CPC
Class: |
E21B 37/02 20130101;
E21B 37/04 20130101 |
Class at
Publication: |
166/312 ;
166/173 |
International
Class: |
E21B 37/00 20060101
E21B037/00 |
Claims
1. A wellbore cleaning tool system for cleaning an interior surface
of the wellbore comprising: a wellbore cleaning tool apparatus
operable to clean a section in a wellbore with brushes, scrapers
and selectively actuated high-velocity jet sprays and operable to
continuously communicate fluid through a hollow center; and, a jet
spray triggering tool apparatus having a jet spray triggering
mechanism which is selectively operable to restrict a flow of the
fluid in the jet spray triggering tool apparatus at a location
below the wellbore cleaning tool apparatus wherein the restriction
causes the fluid to take a path of least resistance to selectively
turn on the high-velocity jet sprays while simultaneously
permitting a limited amount of fluid to flow below the jet spray
triggering tool apparatus.
2. The system of claim 1, wherein the high velocity jet sprays are
arranged in close proximity to the brushes and the scraper and
being operable to clean off and release matter built-on any one
brush or any on scraper.
3. The system of claim 1, wherein the limited amount of the fluid
is operable to flow to a drill bit drilling in the wellbore when
the high velocity jet sprays are on.
4. The system of claim 1, wherein the section being cleaned
comprises one of a blow-out preventer section, a wellhead wear
bushing section, a liner top section, a orifice collar section and
wellbore casing wall section.
5. The system of claim 1, wherein the wellbore cleaning tool
apparatus comprises a casing body having a string of sections, said
string of sections comprises: a top first section; a top second
section, coupled to said top first section, with a first set of
said high-velocity jet sprays installed therein, the top second
section includes fluid exchange ports; a top third section, coupled
to said top second section, with a first set of said scrapers
affixed thereto; a fourth section, coupled to said top third
section, with top and bottom sets of said brushes installed; a
bottom third section, coupled to said fourth section, with a second
set of said scrapers affixed thereto; a bottom second section,
coupled to said bottom third section, with a second set of said
high-velocity jet sprays installed therein; and, a bottom first
section, coupled to said bottom second section.
6. The system of claim 1, wherein the jet spray triggering tool
apparatus comprises: a casing body having a cradle therein; and, a
ported ball seat operable to be cradled in said cradle and having a
cylindrical structure with a hollow center, a seat area and a
plurality of through holes formed in a wall of said cylindrically
structure to permit said limited amount of the fluid to flow
therethrough wherein said jet spray triggering mechanism comprises
a ball operable to be circulated through the wellbore cleaning tool
apparatus to said seat area to restrict the flow of the fluid.
7. The system of claim 1, wherein each of said high-velocity jet
sprays comprise: a spray head with at least one of jet spray
orifice; and, an internal check valve subassembly having a spring
biased plunger to automatically seal close a fluid inlet port to
said jet spray orifice wherein said restriction causes the fluid to
take the path of least resistance which pushes said plunger from
said fluid inlet port to selectively turn on the high-velocity jet
spray through said at least one jet spray orifice.
8. The system of claim 7, wherein the internal check valve
subassembly is operable to shut off automatically said fluid inlet
port when pressure in said wellbore exceed pressure of the
restricted fluid.
9. A wellbore cleaning tool system for cleaning an interior surface
of the wellbore comprising: means for brushing and scraping said
interior surface while continuously communicating fluid down the
wellbore means for selectively spraying said interior surface while
continuously communicating the fluid down the wellbore; and, means
for triggering said spraying means by restricting a flow of the
fluid in the at a location below the brushing and scraping means
and said spraying means wherein the restriction causes the fluid to
take a path of least resistance to selectively turn on the spraying
means while simultaneously permitting a limited amount of fluid to
flow below and down the wellbore.
10. The system of claim 9, wherein the spraying means is arranged
in close proximity to the brushing and scraping means for cleaning
off and releasing matter built-on the brushing and scraping
means.
11. The system of claim 9, wherein the limited amount of the fluid
is operable to flow to a drill bit drilling in the wellbore when
the spraying means are on.
12. The system of claim 9, wherein the interior surface being
cleaned comprises one of a blow-out preventer section, a wellhead
wear bushing section, a liner top section, a orifice collar section
and wellbore casing wall section.
13. The system of claim 9, wherein the brushing and scraping means
and the spraying means are integrated in a wellbore cleaning tool
apparatus comprising: a casing body having a string of sections,
said string of sections comprises: a top first section; a top
second section, coupled to said top first section, with a first set
of sprays of said spraying means installed therein, the top second
section includes fluid exchange ports; a top third section, coupled
to said top second section, with a first set of scrapers affixed
thereto of said brushing and scraping means; a fourth section,
coupled to said top third section, with top and bottom sets of
brushes installed therein of said brushing and scraping means; a
bottom third section, coupled to said fourth section, with a second
set of said scrapers affixed thereto of the brushing and scraping
means; a bottom second section, coupled to said bottom third
section, with a second set of said high-velocity jet sprays
installed therein of said spraying means; and, a bottom first
section, coupled to said bottom second section.
14. The system of claim 9, wherein the spray triggering means
comprises: a casing body having a cradle therein; a ball; and, a
ported ball seat operable to be cradled in said cradle and having a
cylindrical structure with a hollow center, a seat area and a
plurality of through holes formed in a wall of said cylindrically
structure to permit said limited amount of the fluid to flow
therethrough wherein the ball is operable to be circulated through
to said seat area to restrict the flow of the fluid.
15. The system of claim 9, wherein spray means comprises: a spray
head with at least one of jet spray orifice; and, an internal check
valve subassembly having a spring biased plunger to automatically
seal close a fluid inlet port to said jet spray orifice wherein
said restriction causes the fluid to take the path of least
resistance which pushes said plunger from said fluid inlet port to
selectively turn on the high-velocity jet spray through said at
least one jet spray orifice.
16. The system of claim 15, wherein internal check valve
subassembly is operable to shut off automatically said fluid inlet
port when pressure in said wellbore exceed pressure of the
restricted fluid.
17. A method of cleaning an interior surface of the wellbore
comprising the steps of: communicating fluid down hole in a drill
string in the wellbore; brushing matter from said interior surface
while continuously communicating the fluid down hole in the
wellbore; scrapping said matter from said interior surface while
continuously communicating the fluid down hole in the wellbore;
and, selectively spraying via sprays said interior surface to
clean, loosen and release said matter from the interior wall of the
wellbore while continuously communicating the fluid down hole in
the wellbore.
18. The method of claim 17, further comprising the step of:
simultaneously, spraying brushes during the brushing step and
spraying scrapers during the scraping step to loosen and release
matter sticking on or adhering to said brushes and said
scrapers.
19. The method of claim 17, further comprising the step of:
drilling in said wellbore during the communicating, brushing,
scraping and spraying steps.
20. The method of claim 17, further comprising the step of:
floating in said wellbore, during the communicating, brushing,
scraping and spraying steps, debris from a bottom of said
wellbore.
21. The method of claim 17, further comprising the steps of:
floating a ball down hole to restrict a portion of said fluid; and,
increasing pressure in said drill string to turn on said sprays
on.
22. The method of claim 17, further comprising the step of:
automatically turning off said sprays when pressure in said
wellbore is greater than said pressure in said drill string.
23. The method of claim 17, further comprising the step of:
floating in said wellbore, during the communicating, brushing and
scraping steps, debris from a bottom of said wellbore.
24. A wellbore cleaning tool apparatus for cleaning an interior
surface of the wellbore comprising: a casing body adapted to be
centralized in the wellbore; a plurality of brushes coupled to said
casing body for brushing matter from said interior surface; a
plurality of scrapers coupled to said casing body for scrapping
said matter from said interior surface; and, a plurality of jet
spray assemblies, coupled in said casing body, for selectively
emitting jet sprays from jet orifices to clean, loosen and release
said matter from the interior wall of the wellbore and said
plurality brushes and said plurality of scrapers.
25. The apparatus of claim 24, wherein the jet sprays are high
velocity jet sprays which are selectively actuated and arranged in
close proximity to the plurality of brushes and the plurality of
scraper to clean off and release matter built-on any one brush of
said plurality of brushes or any one scraper of said plurality of
scrapers.
26. The apparatus of claim 24, wherein said casing body includes a
string of sections, said string of sections comprises: a top first
section; a top second section, coupled to said top first section,
with a first set of said jet orifices; a top third section, coupled
to said top second section, with a first array of said plurality of
scrapers; a fourth section, coupled to said top third section, with
a set of said plurality of brushes; a bottom third section, coupled
to said fourth section, with a second array of said plurality of
scrapers; a bottom second section, coupled to said bottom third
section, with a second set of said jet orifices; and, a bottom
first section, coupled to said bottom second section.
27. The system of claim 24, wherein each of jet spray assembly
comprises: a spray head with at least one of jet spray orifice;
and, an internal check valve subassembly having a spring biased
plunger to automatically seal close a fluid inlet port to said jet
spray orifice wherein said restriction causes the fluid to take the
path of least resistance which pushes said plunger from said fluid
inlet port to selectively turn on the jet spray through said at
least one jet spray orifice.
28. The system of claim 27, wherein the internal check valve
subassembly is operable to shut off automatically said fluid inlet
port when pressure in said wellbore exceed pressure of the
restricted fluid.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to tools for cleaning a
wellbore and, more particularly, to a cleaning tool system that
brushes, scrapes and selectively sprays, with high-velocity jet
sprays, matter from the interior wall of a wellbore.
[0003] 2. General Background
[0004] Cleaning a wellbore with scraping and brushing has been
employed in the oil field drilling and exploration industry. The
cleaning out of the wellbore is essential so, for example, the flow
of drilling fluid to the annulus of the wellbore remains
unobstructed between tool casings and the interior wall of the
wellbore.
[0005] Drilling operations use drilling fluid (sometimes referred
to as drilling fluid mud) that cakes onto the wellbore. The mud is
very thick and may mix with any oil residue in the wellbore
annulus. Pipe scale and cement sheath can also be found adhering to
the wellbore casing or liner. When cleaning the unwanted mud cake
from the wellbore, the scraped or brushed mud cake (having a
natural tendency to stick and adhere to surfaces) can stick, adhere
and glob on surfaces of the scrapers and brushes. The scrapping and
brushing is performed by metal blades and steel bristles,
respectively. The mud cake may coat the blades and steel bristles
and build-up thereon such that the efficiency of the scrapping and
brushing is diminished.
[0006] Another of the disadvantages of known wellbore cleaning
devices is the accumulation of round trip delays to journal the
cleaning device down hole and to remove the cleaning device, such
as each time the device needs cleaning, replacing broken parts, or
before, during and after drilling operations. The roundtrip delay
time extends the time to complete drilling operations which
increases the cost of operations.
[0007] Furthermore, known wellbore cleaning devices require
repeated cleaning of the brushes and scraper, thus adding
additional round trip delays.
[0008] In view of the above, there is a continuing need for a
wellbore cleaning tool system that employs wellbore cleaning
devices and a convenient and cost-effective means for cleaning said
devices and the interior wall surface of the wellbore while said
devices remain in the wellbore.
[0009] In view of the above, there is a continuing need for a
wellbore cleaning tool system that employs brushes, scrapers and a
convenient and cost-effective means for cleaning the brushes, the
scrapers and the interior wall surface of the wellbore while said
brushes, scrapers remain in the wellbore.
[0010] In view of the above, there is a continuing need for a
wellbore cleaning tool system that employs brushes, scrapers and
selectively actuated high-velocity jet sprays wherein the jet
sprays clean the brushes, the scrapers and the interior wall
surface of the wellbore while said wellbore cleaning tool remains
in the wellbore.
[0011] Another continuing need is for a wellbore cleaning tool
system that can selectively actuate jet sprays without interrupting
drilling operations.
[0012] A still further need is for a wellbore cleaning tool system
that can selectively actuate jet sprays during drilling operations
or while allowing a continuous flow of fluid to the bottom of the
wellbore and/or drill string.
[0013] A still further need is to provide a wellbore cleaning tool
and cleaning tool system that permits fewer trips in and out of the
wellbore.
[0014] A still further need is to provide a wellbore cleaning tool
and cleaning tool system that can, without removing the drill
string from the wellbore, select between wellbore cleaning
operations and wellbore drilling operations.
[0015] As will be seen more fully below, the present invention is
substantially different in structure, methodology and approach from
that of other cleaning tools.
SUMMARY OF THE PRESENT INVENTION
[0016] The preferred embodiment of wellbore cleaning tool apparatus
of the present invention solves the aforementioned problems in a
straight forward and simple manner.
[0017] The present invention contemplates a wellbore cleaning tool
system for cleaning an interior surface of the wellbore comprising:
a wellbore cleaning tool apparatus operable to clean a section in a
wellbore with brushes, scrapers and selectively actuated
high-velocity jet sprays and operable to continuously communicate
fluid through a hollow center; and, a jet spray triggering tool
apparatus having a jet spray triggering mechanism which is
selectively operable to restrict a flow of the fluid in the jet
spray triggering tool apparatus at a location below the wellbore
cleaning tool apparatus wherein the restriction causes the fluid to
take a path of least resistance to selectively turn on the
high-velocity jet sprays while simultaneously permitting a limited
amount of fluid to flow below the jet spray triggering tool
apparatus.
[0018] An object of the present invention is to provide a wellbore
cleaning tool system with high velocity jet sprays arranged in
close proximity to the brushes and the scraper and being operable
to clean off and release matter built-on or accumulated on any one
brush or any one scraper wherein a limited amount of the fluid is
operable to flow to a drill bit (whether or not said drill bit is
drilling) in the wellbore when the high velocity jet sprays are
on.
[0019] A further object of the present invention is to provide a
wellbore cleaning tool system wherein the section being cleaned
comprises one of many sections of a wellbore (for example, but not
limited to, a blow-out preventer section, a wellhead wear bushing
section, a liner top section, an orifice collar section or a
wellbore casing wall section).
[0020] A still further object of the present invention is to
provide a wellbore cleaning tool system with a jet spray triggering
tool apparatus that comprises a casing body having a cradle
therein; and, a ported ball seat operable to be cradled in said
cradle and having a cylindrical structure with a hollow center, a
seat area and a plurality of through holes formed in a wall of said
cylindrical structure to permit said limited amount of the fluid to
flow therethrough
[0021] A still further object of the present invention is to
provide a wellbore cleaning tool system wherein the jet spray
triggering mechanism comprises a ball operable to be circulated
through the wellbore cleaning tool apparatus to said seat area to
restrict the flow of the fluid.
[0022] A still further object of the present invention is to
provide a wellbore cleaning tool system wherein each of the
high-velocity jet sprays comprise a spray head with at least one
jet spray orifice; and, an internal check valve subassembly having
a spring biased plunger to automatically seal close a fluid inlet
port to said jet spray orifice wherein said restriction causes the
fluid to take the path of least resistance which pushes said
plunger from said fluid inlet port to selectively turn on the
high-velocity jet spray through said at least one jet spray
orifice.
[0023] A still further object of the present invention is to
provide a wellbore cleaning tool system wherein the internal check
valve subassembly is operable to shut off automatically said fluid
inlet port when pressure in said wellbore exceeds pressure of the
restricted fluid.
[0024] The present invention further contemplates a method of
cleaning an interior surface of the wellbore comprising the steps
of: communicating fluid down hole in a drill string in the
wellbore; brushing matter from said interior surface while
continuously communicating the fluid down hole in the wellbore;
scrapping said matter from said interior surface while continuously
communicating the fluid down hole in the wellbore; and, selectively
spraying via jet sprays said interior surface to clean, loosen and
release said matter from the interior wall of the wellbore while
continuously communicating the fluid down hole in the wellbore.
[0025] An object of the present invention is to provide a method
for wellbore cleaning which, simultaneously, sprays brushes during
the brushing step and sprays scrapers during the scraping step to
loosen and release matter sticking on or adhering to or otherwise
accumulating on said brushes and said scrapers.
[0026] An object of the present invention is to provide a method
for wellbore cleaning which further comprises the step of: drilling
in said wellbore during the communicating, brushing, scraping and
spraying.
[0027] A still further object of the present invention is to
provide a method for wellbore cleaning which floats in said
wellbore, during the communicating, brushing, scraping and spraying
steps, debris from a bottom of said wellbore.
[0028] A still further object of the present invention is to
provide a wellbore cleaning tool apparatus that is centralized in a
wellbore with top and bottom non-rotating stabilizers and is
adapted to be fully rotational enabling long hours of rotating and
reciprocation typically associated with drilling fluid exchange
operations.
[0029] A still further object of the present invention is to
provide a wellbore cleaning tool apparatus that provides a means
for automatically cleaning the brushes and scrapers of any build-up
or matter sticking or adhering to or otherwise accumulating on such
brushes and scrappers.
[0030] A still further object of the present invention is to
provide a wellbore cleaning tool apparatus that includes a safety
shut-off for shutting off the jet sprays.
[0031] A still further object of the present invention is to
provide a wellbore cleaning tool system that can stay in the
wellbore longer.
[0032] A still further object of the present invention is to
provide a wellbore cleaning tool system that requires less
round-trips into and out of the wellbore during drilling
operations.
[0033] A still further object of the present invention is to
provide a wellbore cleaning tool apparatus that minimizes the
number of moving parts.
[0034] A still further object of the present invention is to
provide a wellbore cleaning tool apparatus that includes easily
replaceable brushes and scrapers.
[0035] A still further object of the present invention is to
provide a single wellbore cleaning tool apparatus designed for
multi-use washing applications including, without limitation,
washing the blowout preventer, washing the wellhead wear bushing,
washing the liner top, washing the orifice collar, washing the
casing's inner diameter wall.
[0036] A still further object of the present invention is to
provide a wellbore cleaning tool apparatus that employs an internal
check valve subassembly and creates pressure differentials in the
casing body of the tool apparatus to trigger the valve plunger to
turn on the jets, such jets being essentially biased to a closed
mode of operation.
[0037] In view of the above objects, it is a feature of the present
invention to provide a wellbore cleaning tool system that is
relatively simple structurally and easy to use.
[0038] Another feature of the present invention is to provide a
wellbore cleaning tool system that is easy to install and that is
selectively activated in a wellbore.
[0039] Another feature of the present invention is to provide a
wellbore cleaning tool system that is selectively activated in a
wellbore and permits drilling operations without removing the drill
string or wellbore cleaning tool from the wellbore.
[0040] Another feature of the present invention is to provide a
wellbore cleaning tool and wellbore cleaning system that is
self-cleaning.
[0041] Another feature of the present invention it to provide a
wellbore cleaning tool and wellbore cleaning system that cleans
during drilling operations.
[0042] The above and other objects and features of the present
invention will become apparent from the drawings, the description
given herein, and the appended claims.
BRIEF DESCRIPTION OF THE DRAWING
[0043] For a further understanding of the nature and objects of the
present invention, reference should be had to the following
description taken in conjunction with the accompanying drawings in
which like parts are given like reference numerals and,
wherein:
[0044] FIG. 1 illustrates a partially exploded view of the wellbore
cleaning tool apparatus in accordance with the present
invention;
[0045] FIG. 2 illustrates a cross-sectional view along the plane
2-2 of FIG. 1;
[0046] FIG. 3 illustrates a side view of the jet spray head of the
wellbore cleaning tool apparatus of FIG. 1;
[0047] FIG. 4 illustrates a front view along the plane 4-4 of FIG.
3;
[0048] FIG. 5 illustrates a rear view along the plane 5-5 of FIG.
3;
[0049] FIG. 6 illustrates an end view along the plane 6-6 of FIG.
4;
[0050] FIG. 7 illustrates a perspective view of the jet spray head
of FIG. 3;
[0051] FIG. 8 illustrates a side view of a valve seat;
[0052] FIG. 9 illustrates a front view of the valve seat of FIG.
8;
[0053] FIG. 10 illustrates a cross-sectional view along the plane
10-10 of FIG. 9;
[0054] FIG. 11 illustrates an exploded view of the jet spray
assembly of the wellbore cleaning tool apparatus of FIG. 1;
[0055] FIG. 12 illustrates a cross-sectional view along the plane
12-12 of FIG. 1;
[0056] FIG. 13 illustrates an exploded view of a set of brushes and
a set of scrapers;
[0057] FIG. 14 illustrates an exploded view of the wellbore
cleaning tool system;
[0058] FIG. 15 illustrates a side view of the ported ball seat of
the wellbore cleaning tool system of FIG. 14;
[0059] FIG. 16 illustrates a cross-sectional view along the plane
16-16 of FIG. 15;
[0060] FIG. 17 illustrates a top view of the ported ball seat along
the plane 17-17 of FIG. 15;
[0061] FIG. 18 illustrates a ball for use with the ported ball
seat;
[0062] FIG. 19 illustrates a perspective view of the ported ball
seat of the wellbore cleaning tool system;
[0063] FIG. 20 illustrates a cross sectional view of the jet
triggering tool apparatus of the wellbore cleaning tool system of
FIG. 14;
[0064] FIG. 21 illustrates a cross-sectional view along the plane
2-2 of FIG. 1 with the valve plunger in a closed position;
[0065] FIG. 22 illustrates a cross sectional view of the jet
triggering tool apparatus of FIG. 20 with the ball seated to
trigger the jet spray assembly and with intermediate positions of
the ball shown in phantom;
[0066] FIG. 23 illustrates a cross-sectional view along the plane
2-2 of FIG. 1 with the valve plunger in an open position as a
result of the ball being seated as shown in FIG. 22;
[0067] FIG. 24 illustrates a diagram of a wellbore, drilling fluid
pumping system, fluid flow and wellbore cleaning tool system
outline for performing the method of cleaning in accordance with
the present invention; and,
[0068] FIG. 25 illustrates a diagram of a wellbore.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0069] Referring now to the drawings and in particular FIGS. 1 and
14, the wellbore cleaning tool apparatus of the present invention
will generally be referenced by the numeral 10 with the wellbore
cleaning tool system being referenced by the numeral 100. The
wellbore cleaning tool apparatus 10 includes, in general, a casing
body 20 adapted to be centralized in the wellbore 5 (FIG. 24) via
top and bottom stabilizers (NOT SHOWN), a plurality of sets of
brushes 30a and 30b, a plurality of sets of scrapers 40a and 40b
and a plurality of sets of jet spray assemblies 50a and 50b for
high-velocity jet spraying of the interior wall of the wellbore 5
for an added cleanout effect. As will be seen from the description
provided below, the high-velocity jet sprays also aid in cleaning
the plurality of sets of brushes 30a and 30b and the plurality of
sets of scrapers 40a and 40b during cleaning operations so that any
build-up of the mud cake, cement sheath, etc., when being brushed
or scraped from the interior wall, on the a plurality of sets of
brushes 30a and 30b and the plurality of sets of scrapers 40a and
40b can be continuously sprayed or cleaned off and released to the
fluid in the annulus of the wellbore 5.
[0070] The casing body 20 includes top and bottom ends 15a and 15b
for connecting the apparatus 10 in the drill string 7 to other
tools, devices, such as the stabilizers (NOT SHOWN) or more drill
string 7. The top and bottom ends 15a and 15b, in the exemplary
embodiment are shown as threaded. Thus, apparatus 10 may be
directly connected to jet triggering assembly 80 (with apparatus 10
directly on top of jet triggering assembly 80 as shown in FIG. 14,
in which case 207 does not represent drill string or any other
element but is merely a drawing convention intended to show that
apparatus 10 is connected (threaded) to jet triggering assembly 80
at threads 83a) or apparatus 10 may be directly connected to drill
string 207 interposed between apparatus 10 and jet triggering
assembly 80 (again, with apparatus 10 on top (but not directly on
top due to the interposed drill string 207) as shown in FIG. 14).
Also, a plurality of the apparatus 10 may be installed at various
spots in a drill string yet only one jet triggering assembly 80 is
required so long as the jet triggering assembly 80 is installed in
the drill string below all of the plurality of apparatus 10.
[0071] Referring also to FIGS. 1, 2, 12 and 13, the plurality of
sets of brushes 30a and 30b, the plurality of sets of scrapers 40a
and 40b and the plurality of sets jet spray assemblies 50a and 50b
are slid in, affixed to and embedded in, respectively, the casing
body 20. The casing body 20 includes a cylindrically shaped
structure dimensioned to be journalled down the annulus of wellbore
5 and has a linearly straight hollow center C for communicating
fluid therethrough. The cylindrically shaped structure has first
(top and bottom) sections 22 with a first wall thickness T1 and
second (top and bottom) sections 24 with a second wall thickness T2
wherein the hollow center C maintains, essentially, the same
diameter along the length of the casing body 20. The ends of the
second sections 24 transitioning from or to the wall thickness T1
of the first sections 22 transition at a 45.degree. angle.
[0072] The second sections 24 have a length of approximately 8.000
inches and a diameter of approximately 5.127 inches. The first
sections 22 have a length of approximately 18.000 inches and a
diameter of approximately 4.370 inches. The diameter of the hollow
center C is approximately 1.250 inches. In the second sections 24,
the plurality of sets of jet spray assemblies 50a and 50b are
embedded or recessed in a respective cavity 25 formed in the casing
body 20.
[0073] The cylindrically shaped structure further includes third
(top and bottom) sections 26 and a fourth section 28. The third
sections 26 have a third wall thickness T3 smaller than the first
wall thickness T1. The top third section 26 is positioned
immediately adjacent the top end of the fourth section 28. The
bottom third section 26 is positioned immediately adjacent the
bottom end of the fourth section 28. The third section 26 has a
diameter of 3.120 inches.
[0074] Since each set of brushes 30a and 30b are identical, only
one such set of brushes will be described in detail. The set of
brushes 30a includes a plurality of brush units 32a, 32b, 32c and
32d where each brush unit is essentially identical. Thus, only one
such brush unit 32a will be described in detail. Brush unit 32a
includes an array 35 of bristle clusters 37a, 37b, 37c, 37d, 37e
and 37f. The brush unit 32a further includes a brush chassis 33
with a plurality of holes 34 formed therein, where each hole 34
receives a respective one of the bristle clusters 37a, 37b, 37c,
37d, 37e and 37f. Each bristle cluster includes a band 39 which
bundles together the bristle cluster and is received or secured in
hole 34. The brush chassis 33 includes a guide or flange 36
projecting laterally from the side of the brush chassis 33. In the
exemplary embodiment, the longitudinal length of slots 42 are
angled, arched or curved. Furthermore, in the preferred embodiment,
a plurality of brush units 32a, 32b, 32c and 32d when installed
form a 45.degree. left hand brush array 35 and are contoured to fit
in the annulus of the interior wall of the wellbore 5 without
bending or crushing of the bristles of the bristle clusters 37a,
37b, 37c, 37d, 37e and 37f. In the exemplary embodiment, the
bristles of the bristle clusters are made of steel or other durable
metal.
[0075] The set of brushes 30b are identical to the set of brushes
30a. However, slot 42' is oriented to curve in a right handed
counterclockwise direction. On the other hand, slot 42 is oriented
to curve in a left handed clockwise direction. Hence, the set of
brushes 30b are installed to create a 45.degree. right hand brush
array 35'.
[0076] Returning again to the casing body 20, in a top end of the
fourth section 28, a top set of slots 42 are formed therein for
installation of the set of brushes 30a around the circumferential
perimeter of the fourth section 28. In the bottom end of the fourth
section 28, a second set of slots 42' are formed therein. The
second set of slots 42' receive the set of brushes 30b. The top end
of the fourth section 28 has a top edge 29a while the bottom end
has a bottom edge 29b. Moreover, the opening of each slot 42 is
along the top edge 29a while the opening of each slot 42' is along
the bottom edge 29b.
[0077] The slot 42 is contoured to track the shape of the brush
chassis 33 and includes a recessed groove 43. The recessed groove
43 receives and mates with the guide or flange 36. Thereby, the
brush chassis 33 is cradled in the slot 42 and does not fall
through the slot 42.
[0078] When assembling or replacing one or more of the brush units
32a, 32b, 32c and 32d, the brush chassis 33 can be easily slid in
and out of its respective slot 42 via the opening. As will be seen
from the description provided below, in the exemplary embodiment,
the brush units 32a, 32b, 32c and 32d of the set of brushes 30a are
locked into their respective slot 42 via the bracelet clamp 45 of
the set of scrapers 40a clamped to the top third section 26.
Likewise, the brush units of the set of brushes 30b are locked into
their respective slot 42' via the bracelet clamp 45 of the set of
scrapers 40b.
[0079] Referring still to FIGS. 12 and 13, since each set of
scrapers 40a and 40b are identical, only one such set of scrapers
40a will be described in detail. The set of scrapers 40a includes a
two-piece bracelet clamp 45 having integrated thereon an array of
circumferentially spaced blade units 44a, 40b, 44c, 44d, 44e and
44f. The two-piece bracelet clamp 45 clamps together the
spaced-apart blade units 44a, 40b, 44c, 44d, 44e and 44f around the
top third section 26. Likewise, the set of scrapers 40b are clamped
circumferentially around the bottom third section 26.
[0080] The bracelet clamp 45 includes two separate semi-circular
sections 46a and 46b. The bracelet clamp 45 when secured or
fastened together has an inner circumference that tracks the outer
circumference of the third section 26 of the casing body 20. The
two semi-circular sections 46a and 46b includes first and second
(right and left) aligned hole sets 47a and 47b intended to receive
fasteners 48a and 48b, respectively, such as a screw or bolt, to
fasten or clamp together the two semi-circular sections 46a and
46b. Loosening and removing the fasteners 48a and 48b allow the set
of scrapers 40a to be removed and/or replaced when worn or damaged.
The length of the bracelet clamp 45 extends from the bottom of the
second section 24 to the top edge 29a of the fourth section. In
view of the foregoing, fastening or clamping the bracelet clamp 45
locks the brush units 32a, 32b, 32c and 32d of the set of brushes
30a by closing the opening to slot 42 and serves as a retainer cap
to maintain the brush units 32a, 32b, 32c and 32d in their
respective (angled) slot 42.
[0081] In the preferred embodiment, the scrapers are not spring
loaded. Standard scrapers used in the industry often use spring
loaded scrapers; and, spring loaded scrapers could be used with
this tool 10.
[0082] Referring now to FIGS. 2-11, the sets of jet spray
assemblies 50a and 50b will now be described in detail. However,
since each of the jet spray assembly of the set 50a and the set 50b
is identical, only one such jet spray assembly 50a will be
described. The jet spray assembly 50a comprises a spray head 51
having two jet spray orifices 52a and 52b and an internal check
valve subassembly 60. The spray head 51 includes two (top and
bottom) recessed holes 54a and 54b adapted to receive fasteners 56a
and 56b, respectively. The fasteners 56a and 56b are screws or
blots with heads that are adapted to be recessed in the holes 54a
and 54b. In the exemplary embodiment, the spray head 51 has
rearwardly projecting guide prongs 58 intended to align with holes
formed in a valve seat 62 nestled in the second section 24 behind
the spray head 51. The spray head 51 further includes a center
aperture 59 between the two jet spray orifices 52a and 52b.
[0083] The internal check valve subassembly 60 includes the valve
seat 62 having a front side mated with the spray head 51 and a back
side dimensioned to be seated in the cavity 25 in the second
section 24. The back side has a fluid inlet port 64 has a coupler
64a adapted with a recessed groove 66 for receipt of an O-ring 68.
The front side of the valve seat 62 has an elongated opening 70
with a gasket 72 placed between the spray head 51 and such front
side. The center axis of the elongated opening 70 is aligned with
the center axis of the fluid inlet port 64. The center axis of the
fluid inlet port 64 is also aligned with the center aperture 59.
The fluid inlet port 64 is aligned with a fluid exchange port in
the casing body 20 (section 24). The fluid inlet port 64 is shown
as one with the fluid exchange port which is not separately
numbered.
[0084] The internal check valve subassembly 60 further comprises a
valve plunger 74 having a plunger head 75 and a plunger shaft 76.
The valve plunger 74 is spring biased to a closed position (FIGS. 2
and 21) via spring 78 wound around plunger shaft 76 and presses
against the surface around the center aperture 59. The plunger
shaft 76 is adapted to be received in the center aperture 59. The
valve plunger head 75 is generally shaped as a pyramid. The apex of
the pyramid when in the closed position is received in the fluid
inlet port 64 such that fluid flowing in the hollow center of the
casing body 20 is prevented from passing out of the fluid inlet
port 64 and into the valve seat 62. The internal check valve
subassembly 60 will remain closed so that the jet spray orifices
52a and 52b will remain closed, as well.
[0085] In the preferred embodiment, a first set of jet spray
assemblies 50a are embedded in the casing body 20 at a location
above the set of brushes 30a and the set of scrapers 40a. In the
exemplary embodiment, the first set of jet spray assemblies 50a
includes two jet spray assemblies 50a spaced 1800 from the other.
On the other hand, the second set of jet spray assemblies 50b are
embedded in the casing body 20 at a location below the set of
brushes 30b and the set of scrapers 40b. In the exemplary
embodiment, the second set of jet spray assemblies 50S includes two
jet spray assemblies 50b spaced 1800 from the other. However, the
second set of jet spray assemblies 50b are offset from the first
set of jet spray assemblies 50a by 90.degree.. Thus, the plurality
of sets of jet spray assemblies 50a and 50b project high velocity
jet sprays from the casing body 20 at 0.degree. (360.degree.),
90.degree., 180.degree., and 270.degree.. As can be appreciated,
additional jet spray assemblies may be included.
[0086] When moving from drilling to completion, the wellbore 5
needs to be cleaned. Commonly, jets are placed on every tool body
for each transition. However, this becomes a problem when going
down hole.
[0087] Referring now to FIG. 14, the wellbore cleaning tool system
100 is shown. The system 100 includes the wellbore cleaning tool
apparatus 10 and the jet triggering assembly 80 coupled at a
location in the drill string 7 below the wellbore cleaning tool
apparatus 10. In the embodiment of FIG. 14, the jet triggering tool
apparatus 80 is preferably positioned anywhere along the drill
string 7 below the wellbore cleaning tool apparatus 10 but before
the drill bit 110. In operation, the jet triggering tool apparatus
80 is constructed and arranged to selectively trigger the opening
or closing of the internal check valve subassembly 60 which turns
the high-velocity jet sprays ON or OFF, respectively. In FIG. 23,
the internal check valve subassembly 60 is open to permit the flow
of fluid through the fluid inlet port 64 (and, it is open due to
the ball 105 being seated in the jet triggering assembly 80 as
shown in FIG. 22 and the back pressure created thereby when fluid
flows in C in the direction shown in FIG. 23). In FIG. 21, the
internal check valve subassembly 60 is closed to stop the flow of
fluid through the fluid inlet port 64 (and it is closed as the ball
105 is not seated in the jet triggering assembly 80 as shown in
FIG. 20).
[0088] Referring now to FIGS. 15-20, the jet triggering tool
apparatus 80 comprises casing body 82 having a hollow center C'
adapted to allow fluid to flow therethrough down to the drill bit
110 before, during and after cleaning operations. In other words,
the jet triggering tool apparatus 80 is constructed and arranged to
allow for a continuous flow of fluid to the drill bit 110 or other
tools located down stream, as needed. The casing body 82 (for
illustrative purposes) is shown to have a top-end coupler 83a which
is threaded, as shown in the cut-away portion, in a manner to mate
with the bottom end coupler 15b of the wellbore cleaning tool
apparatus 10 or the bottom end coupler of any interposed drill
string 7. Below the top-end coupler 83a, the casing body 82 has a
cradle 85 formed therein for receipt of a ported ball seat 90. The
casing body 82 (for illustrative purposes) is shown to have a
bottom-end coupler 83b which is threaded, as shown in the cut-away
portion, for attachment of another tool. In the example, the drill
bit 110 is shown immediately below the casing body 82 or more drill
string 7.
[0089] The ported ball seat 90 provides a means for triggering the
internal check valve subassembly 60 from the first mode of
operation to the second mode of operation when ball 105 is seated
therein, as best seen in FIG. 22. The ported ball seat 90 includes
a cylindrical structure 94 having a hollow center C2 formed in the
center of its longitudinal length or axis. The ball 105 may be a
float Baker-Lite ball. The cylindrical structure 94 has a plurality
of circumferential grooves 94a formed therein. The plurality of
circumferential grooves 94a receive O-rings 99 (FIG. 22).
[0090] The top end inner diameter ID.sub.T of the hollow center C2
gradually tapers at approximately 30.degree. from 2.062 to 0.9375
inches. Thereafter, the inner diameter 11D of the hollow center C2
is the same (0.9375 inches) until a predetermined distance D1 from
the bottom end. At the bottom end, the inner diameter slopes
approximately 45.degree. for slightly less than 0.2000 of an inch
from 0.9375 to approximately 0.7500 inches. The bottom end inner
diameter ID.sub.B is approximately 0.7500 inches. The gradually
tapering inner diameter provides a ball seat area 96 for seating
the ball 105 therein, as best seen in FIG. 22. The length of the
cylindrical structure 94 is approximately 5.000 inches and the
outer diameter OD is approximately 2.406 inches.
[0091] Additionally, the wall structure of the cylindrical
structure 94 has formed therein a plurality of spaced apart through
holes 98 each having a longitudinal axis that is parallel with the
longitudinal axis of the cylindrical structure 94. The through
holes 98 extend from the top end to the bottom end of the
cylindrical structure 94 and permit the flow of fluid in the hollow
center C to flow therethrough. The through holes 98 are spaced
apart approximately 45.degree. with a diameter of 0.2500 to 0.2450
inches. In the preferred embodiment, the inner diameter of the
through holes 98 is significantly smaller than the inner diameter
ID of hollow center C2.
[0092] In the exemplary embodiment, there are eight (8) through
holes 98 which are constructed and arranged to permit a sufficient
amount of drilling fluid to flow though the ported ball seat 90
down to drill bit 110 such as during drilling operations.
Therefore, the wellbore cleaning tool apparatus 10 does not need to
be removed. Hence, any delays for trips in and out of the wellbore
to install or de-install the wellbore cleaning tool apparatus 10 is
effectively eliminated. Moreover, the amount of fluid flowing
downstream through the through holes 98 can be controlled by
closing one or more of the through holes 98 before installing
system 100 down hole.
[0093] The jet triggering tool apparatus 80 may include a float
valve (NOT SHOWN) directly below the ported ball seat 90 to allow
for reverse circulating.
[0094] The operation of the internal check valve subassembly 60 in
combination with the jet triggering tool apparatus 80 will now be
described.
[0095] In a first mode of operation, the internal check valve
subassembly 60 is closed as best seen in FIGS. 2 and 21. The bias
spring force exerted by the spring 78 biases the apex of the
pyramid of the plunger head 75 in the fluid inlet port 64 such that
fluid flowing in the hollow center C of the casing body 20 is
prevented from passing out of the fluid inlet port 64 and into the
valve seat 62. Thereby, the internal check valve subassembly 60 is
closed and the high velocity jet sprays through orifices 52a and
52b are OFF. The first mode of operation maintains the jet sprays
OFF.
[0096] It should be noted, the spring biasing force is stronger
than a first predetermined PSI (pressure per square inch) in the
hollow center C of casing body 20. Thereby, fluid flowing in the
casing body 20 is not squirted, jetted, streamed or sprayed out
through the orifices 52a and 52b until the pressure in the hollow
center C exceeds the first predetermined PSI. In this mode, the
ball 105 is not seated in ported ball seat 90 of the jet triggering
tool apparatus 80.
[0097] In a second mode of operation, once the first predetermined
PSI is exceeded, the fluid in the hollow center C exerts a
sufficient counter force to push (trigger the transition of) the
plunger head 75 out of the fluid inlet port 64 such that some fluid
flowing in the hollow center C of the casing body 20 flows from the
fluid inlet port 64 and into the valve seat 62. Thereby, the
internal check valve subassembly 60 is open and the high velocity
jet sprays through the orifices 52a and 52b are ON.
[0098] The PSI in the hollow center C is increased above the first
PSI by floating ball 105 down casing body 20 to the jet triggering
tool apparatus 80 such that ball 105 is seated in the ball seat
area 96. When the ball is seated in the ball seat area 96, a
restriction is created causing some of the fluid to take the path
of least resistance through the internal check valve subassembly 60
(noting that some of the fluid can still flow through holes 98).
The internal check valve subassembly 60 remains ON until the
pressure in the annulus of wellbore 5 outside of the casing body 20
is greater than the second predetermined PSI or the pressure in the
casing body 20 is below the second predetermined PSI whereby the
spring biasing force closes the fluid inlet port 64 with the
plunger head 75.
[0099] In the second mode, fluid from the center C of casing body
20 is squirted, jetted, streamed or sprayed out at a high velocity
through the orifices 52a and 52b. For example, upon completion of
the jetting application, the ball 105 may be extracted by reverse
circulation. Thus, the high-velocity jet sprays are selectively
turned OFF. The ball 105 serves as the jet spray triggering
mechanism to restrict the fluid flow to turn the sprays ON and to
un-restrict the fluid flow to turn the sprays OFF.
[0100] In a third mode of operation, if the second predetermined
PSI in hollow center C is exceeded in the annulus of the wellbore
5, the internal check valve subassembly 60 is constructed and
arranged to immediately shut OFF by exerting pressure though the
center aperture 59 on plunger shaft 76. The valve plunger 74 is
thereby pushed (triggering the transition of) the plunger head 75
to a closed position (FIGS. 2 and 21). The apex of the pyramid when
in the closed position is received in the fluid inlet port 64
However, in the third mode, fluid in the annulus of the wellbore 5
is prevented from reaching in the hollow center C. The third mode
of operation is a safety shut-off feature to prevent a reversed
flow of the jet stream.
[0101] If all internal check valve subassembly 60 are constructed
and arranged to trigger or transition between modes on the same
first predetermined PSI and second predetermined PSI, then all jet
sprays would be effectively turned on and off essentially
simultaneously with a single jet spray triggering mechanism (ball
105).
[0102] In view of the foregoing, the design described above can be
varied. For example, the spring 78 can be replaced by removing the
spray head 51. Therefore, the strength of the spring 78 can be
varied, as needed for different wellbore 5 characteristics, to
increase or decrease the biasing force proportionately to at least
the first predetermined PSI. The number and size of the through
holes 98 may also be varied.
[0103] The number and size of jet spray orifices 52a and 52b in the
spray head 51 may be varied. Furthermore, the casing bodies 20 and
82 may be varied by changing the scheduled pipe size. In most
applications, a 95/8 inch schedule pipe and a 7 inch schedule pipe
will be used.
Cleaning Operations
[0104] Referring now to FIG. 24, the wellbore 5 (through which
drilling operations occur) includes a plurality of sections wherein
the top section is a riser section 6a which in turn is followed by
a blow-out preventer section 6b. The blow-out preventer (BOP)
section 6b is followed by an intermediate casing 6c which in turn
is followed by a casing liner 6d.
[0105] The wellbore cleaning tool system 100 brings a third
dimension of cleaning to scraping and brushing when cleaning out
the wellbore 5 including below the blow-out preventer 6b or 8b. The
wellbore cleaning tool apparatus 10 is effective in removing mud
cake, oily residue, cement sheath, and pipe scale (hereinafter
referred to as "matter"). The wellbore cleaning tool apparatus 10
is designed to provide superior contact at all angles of
inclination and may be oriented pin-up or pin-down. Furthermore,
the wellbore cleaning tool apparatus 10 is fully rotational and
centralized by non-rotating top and bottom stabilizers (NOT SHOWN)
to protect the wellbore from wear and enabling long hours of
rotating and reciprocation typically associated with drilling fluid
exchange operations.
[0106] During normal drilling operations, the drilling fluid path
120 is shown. Drilling fluid from fluid tank 122 is pumped via pump
source 124 using pump gauges 126, in the direction of ARROWS A,
down the wellbore 5 through a preliminary length of drill string 7
to the wellbore cleaning tool system 100. At the wellbore cleaning
tool system 100, the fluid further flows down the hollow center C,
through center C' of the jet triggering tool apparatus 80 (with the
ported ball seat 90), then out of the drill bit 110 and up the
annulus of the wellbore 5, in the direction of ARROWS B, without
any restrictions. In general, the fluid is pumped by the pump
source 100 such that, at the wellbore cleaning tool apparatus 10,
the PSI is below the first predetermined PSI. During the normal
drilling operation, the internal check valve subassembly 60 will
remain closed so that the jet spray orifices 52a and 52b are
OFF.
[0107] The fluid flowing in the direction of ARROWS B is recycled
by circulating the fluid, in the direction of ARROWS C, out through
the annulus of the wellbore 5 through shale shackers 128 and a
filter unit 130. The fluid flowing through the filter unit 130 is
sent back to the fluid tank 122 where it is stored until
recycled.
[0108] As can be ready seen, the wellbore cleaning tool system 100
does not interrupt or restrict the flow of the drilling fluid
during normal operations. Thus, one (or more) of well bore cleaning
tool 10 of the wellbore cleaning tool system 100 can be installed
in the wellbore 5 until needed.
[0109] The drilling fluid path described herein in relation to FIG.
24 is for illustrative purposes only. The production of drill fluid
and the circulation thereof has been well established in the oil
field exploration industry and does not require further
explanation. In FIG. 25 another wellbore arrangement is shown. The
wellbore 5' includes a riser section 8a followed by a blow-out
preventer (BOP) section 8b. The blow-out preventer (BOP) section 8b
is followed by a wellhead wear bushing 8c where the inner diameter
of the wellbore decreases immediately below the bushing 8c. The
section below the wellhead wear bushing 8c terminates at a liner
top 8d. The liner top 8d is followed by a section of casing wall 8e
having a inner diameter smaller than the liner top 8d. The casing
wall 8e has an orifice collar 8f. In operation, the system 100 is
operable to clean and wash one or more of the BOP section 8b, the
wellhead wear bushing 8c, the liner top 8d, the orifice collar 8f
and casing wall 8e while allowing fluid to continuously flow all
the way to the end of the drill string or bottom of the wellbore
5.
[0110] Cleaning of the wellbore 5 with scraping and brushing can
take place essentially continuously during drilling operations
since system 100 can be installed anywhere on the drill string
above the drill bit 110. Accordingly, two-dimensional cleaning, via
brushing and scraping, can take place continuously. The continuous
flow of fluid floats removed (brushed and/or scraped) debris to the
top of the wellbore 5. Even if not drilling, the cleaning
operations can take place in the wellbore 5 with the benefits of
the drilling fluid recirculated up the annulus to assist in washing
the "matter" being knocked off of the scrapers, brushers and inner
wellbore 5.
[0111] To add the third dimension of cleaning, high-velocity jet
sprays through orifices 52a and 52b are turned ON. To turn the
high-velocity jet sprays ON, the ball 105 is pumped down, in the
direction of ARROWS A, with the fluid flowing through the hollow
center C of the casing body 20 to ported ball seat 90. Since the
ball 105 has an OD greater than the ID of the ball seat area 96,
the ball 105 is seated or cradled in the recessed area of the ball
seat area 96 restricting or sealing off the flow of fluid through
hollow center C2. The restriction causes some of the fluid to take
the path of least resistance which is through the internal check
valve subassembly 60 and the jet spray orifices 52a and 52b as the
force (PSI) exerted by the fluid is stronger than spring 78 (again,
noting that some of the fluid can flow through the holes 98).
Thereby, plunger head 75 is moved out of the fluid inlet port 64,
which then becomes open. As can be appreciated, the restriction
increases the PSI of the fluid flowing in hollow center C above the
first predetermined PSI, thereby triggering the transition from the
first mode to the second mode.
[0112] In the preferred embodiment, limited fluid flow through the
ported ball seat 90 via the plurality of spaced apart through holes
98 to the drill bit 110 is permitted after the ball 105 has been
seated in the ball seat area 96. The application of the ball 105
seated in ball seat area 96 and the fluid being re-directed through
the jets spray orifices 52a and 52b is observed remotely by the
operator via pump gauges 126. Flow rates are established before the
ball 105 is pumped down to the ported ball seat 90. After the ball
105 is pumped down the same flow rate will be used. An increase in
fluid pressure (PSI) occurs when the ball 105 is seated in the
ported ball seat 90.
[0113] In the preferred embodiment, no more than 20 bbls. per
minute and no more than 3000 PSI is applied.
[0114] During cleanout operations, the wellbore cleaning tool
apparatus 10 brushes via the sets of brushes 30a and 30b and
scrapes via the sets of scrapers 40a and 40b the "matter" on the
interior wall of the wellbore 5. Thereby, "matter" may buildup or
stick on the brushes and scrapers. The third dimension of cleaning
by the jet spray orifices 52a and 52b to produce high-velocity jet
sprays loosen and clean "matter" on the interior wall and on the
sets of brushes 30a and 30b and the sets of scrapers 40a and
40b.
[0115] Upon completion of the cleanout operations, the ball 105 is
extracted from the ported ball seat 90. The ball extraction takes
place by reverse circulating the ball 105 up the tool apparatus 10
and casing 7. Alternately, the ball 105 can be extracted by
allowing the ball 105 to float up the tool apparatus 10 and drill
string 7 when a float valve (NOT SHOWN) is used in the tool
apparatus 10 which will not allow for reverse circulation.
[0116] While not wishing to be bound by theory, a ball 105 of 0.875
is pumped down at approximately 11 feet per second as per pumping
10 bbls. minute. Once the ball 105 is seated, approximately
two-thirds of the fluid will still flow through the through holes
98 down to the drill bit 110 allowing for debris to be pushed up
the annulus from the bottom of the wellbore 5 or drill bit 10. The
projected restriction in the fluid is approximately 5 ft. per
second as per pumping bbls. minute.
[0117] Because many varying and differing embodiments may be made
within the scope of the inventive concept herein taught and because
many modifications may be made in the embodiment herein detailed in
accordance with the descriptive requirement of the law, it is to be
understood that the details herein are to be interpreted as
illustrative and not in a limiting sense.
* * * * *