U.S. patent application number 15/000233 was filed with the patent office on 2016-07-21 for flowline and injection tee for frac system.
The applicant listed for this patent is GE Oil & Gas Pressure Control LP. Invention is credited to Ana Ayres, Kwong-Onn Chan, Gajanan Hegde, Jason Williams.
Application Number | 20160208570 15/000233 |
Document ID | / |
Family ID | 56407444 |
Filed Date | 2016-07-21 |
United States Patent
Application |
20160208570 |
Kind Code |
A1 |
Ayres; Ana ; et al. |
July 21, 2016 |
Flowline and Injection Tee for Frac System
Abstract
A hydraulic fracturing assembly includes a frac tree that mounts
to a wellhead. An injection tee mounts to the tree, the injection
tee having an axial injection tee bore that registers with an axial
flow bore of the frac tree. A single inlet passage in the injection
tee extends from a flowline mounting face on an exterior portion of
the injection tee downward and inward into a junction with the
axial flow bore. A wear resistant inlet passage sleeve extends from
the mounting face of the injection tee a selected distance into the
inlet passage. The inlet passage sleeve is of a harder material
than the injection tee. A flowline connects to the mounting face to
deliver fluid into the inlet passage. The flowline has an upward
curved section and an inclined section that joins the curved
section and extends downward and outward away from the injection
tee.
Inventors: |
Ayres; Ana; (Calgary,
CA) ; Chan; Kwong-Onn; (Calgary, CA) ;
Williams; Jason; (Calgary, CA) ; Hegde; Gajanan;
(Calgary, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GE Oil & Gas Pressure Control LP |
Houston |
TX |
US |
|
|
Family ID: |
56407444 |
Appl. No.: |
15/000233 |
Filed: |
January 19, 2016 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
62105355 |
Jan 20, 2015 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E21B 43/26 20130101;
E21B 17/1007 20130101; E21B 33/068 20130101 |
International
Class: |
E21B 33/068 20060101
E21B033/068; E21B 34/02 20060101 E21B034/02 |
Claims
1. A hydraulic fracturing assembly, comprising: a hydraulic
fracturing tree having an axis and adapted to be mounted to a
wellhead of a well with the axis vertical, the tree having an axial
flow bore and valves that open and close the flow bore; an
injection tee mounted to the tree, the injection tee having an
axial injection tee bore that registers with the axial flow bore; a
single inlet passage in the injection tee that extends from a
flowline mounting face on an exterior portion of the injection tee
downward and inward into a junction with the axial flow bore; a
wear resistant inlet passage sleeve that extends from the mounting
face of the injection tee a selected distance into the inlet
passage, the inlet passage sleeve being of a harder material than
the injection tee; and a flowline connected to the mounting face to
deliver fluid into the inlet passage, the flowline having an upward
curved section and an inclined section that joins the curved
section and extends downward and outward away from the injection
tee.
2. The assembly according to claim 1, wherein: the inlet passage
has an upward and outward facing shoulder; and the inlet passage
sleeve has a lower end that abuts the shoulder.
3. The assembly according to claim 1, wherein: the inlet passage
has an upward and outward facing shoulder spaced from the junction
with the injection tee bore, defining an outer portion of the inlet
passage and an inner portion of the inlet passage, the outer
portion having a greater inner diameter than an inner diameter of
the inner portion; and the inlet passage sleeve has a lower end
that abuts the shoulder, the inlet passage sleeve having an inner
diameter that is the same as the inner diameter of the inner
portion.
4. The assembly according to claim 1, wherein: the mounting face is
flat: and the inlet passage sleeve has an outer portion that
protrudes outward past the mounting face.
5. The assembly according to claim 1, further comprising: a wear
resistant injection tee bore sleeve positioned at a junction of the
injection tee bore with the flow bore, the injection tee bore
sleeve having a greater hardness than the injection tee.
6. The assembly according to claim 1, further comprising: a support
having a plurality of extensible legs, each having a clamp on an
upper end that secures to a portion of the flowline and a base on a
lower end for placement on ground.
7. The assembly according to claim 1, further comprising: a support
for the flowline, the support comprising: a plurality of legs that
are selectively extensible in length; a clamp on an upper end of
each of the legs that secures to a portion of the flowline; a base
on a lower end of each of the legs; and an anchor stake extending
from the base for imbedding in ground.
8. The assembly according to claim 1, wherein: the flowline
comprises a plurality of pipe joints having ends secured together;
and at least one of the pipe joints is extensible in length.
9. The assembly according to claim 1, further comprising: a brace
having an upper end connected to the injection tee and a lower end
connected to a lower portion of the tree, the brace being located
on an opposite side of the injection tee from the mounting
face.
10. The assembly according to claim 1, further comprising: a flow
back passage extending from the injection tee bore outward in a
direction opposite from the mounting face.
11. A hydraulic fracturing assembly, comprising: a hydraulic
fracturing tree having an axis and adapted to be mounted to a
wellhead of a well with the axis vertical, the tree having an axial
flow bore and valves that open and close the flow bore; an
injection tee mounted to an upper end of the tree, the injection
tee having an axial injection tee bore that registers with the flow
bore; a single inlet passage in the injection tee that extends from
a supply mounting face on the exterior portion of the injection tee
downward and inward into a junction with the axial injection tee
bore; a flow back passage in the injection fee for flowing back
well fluid from the well, the flow back passage extending from a
flow back mounting face on an exterior portion of the injection tee
to a junction with the axial injection tee bore, the flow back
mounting face being on an opposite side of the injection tee from
the supply mounting face; and a supply flowline connected to the
supply mounting face to deliver fluid into the inlet passage, the
supply flowline having an upward curved section that joins the
exterior portion of the tree, and an inclined section that joins
the curved section and extends downward and outward away from the
tree.
12. The assembly according to claim 11, wherein; the inlet passage
has an upward and outward feeing shoulder spaced from the junction
with the injection tee bore, defining an outer portion of the inlet
passage and an inner portion of the inlet passage, the outer
portion having a greater inner diameter than an inner diameter of
the inner portion; and the assembly further comprises a wear
resistant inlet passage sleeve installed in the outer portion of
the inlet passage, the inlet passage sleeve having a lower end that
abuts the shoulder, the inlet passage sleeve having an inner
diameter that is the same as the inner diameter of the inner
portion, and the inlet passage sleeve being of a harder material
than the injection tee.
13. The assembly according to claim 12, wherein: the inlet passage
sleeve has an outer portion that protrudes outward past the
mounting face.
14. The assembly according to claim 12, further comprising: a wear
resistant injection tee bore sleeve positioned at a junction of the
injection tee bore with the flow bore, the injection tee bore
sleeve having a greater hardness than the injection tee.
15. The assembly according to claim 11, wherein: the supply
flowline comprises a plurality of tubular members having ends
secured together; at least one of the tubular members comprises:
inner and outer tubes that telescope relative to each other;
external inner tube and outer tube flanges that face one another;
threaded rods extending from the inner tube flange through
apertures in the outer tube flange; and a nut that engages each of
the threaded rods to fix a distance between the inner tube and the
outer tube flanges.
16. A hydraulic fracturing assembly, comprising: a hydraulic
fracturing tree having an axis and adapted to be mounted to a
wellhead of a well with the axis vertical, the free having an axial
flow bore and valves that open and close the flow bore; an
injection tee mounted to an upper end of the tree, the injection
tee having an axial injection tee bore that registers with the flow
bore: a single inlet passage in the injection tee that extends from
a supply mounting face on the exterior portion of the injection tee
downward and inward into a junction with the axial injection tee
bore; a supply flowline connected to the supply mounting face to
deliver fluid into the inlet passage, the supply flowline having an
upward curved section that joins the exterior portion of the tree,
and an inclined section that joins the curved section and extends
downward and outward away from the tree; a plurality of support
legs that are selectively extensible in length; a clamp on an upper
end of each of the legs that secures to a portion of the supply
flowline; a base on a lower end of each of the legs; and an anchor
stake extending from the base for imbedding in ground.
17. The assembly according to claim 16, further comprising; at
least one cross member extending between at least two of the legs
perpendicular to the legs.
18. The assembly according to claim 16, wherein: the supply
flowline comprises a plurality of tubular members having ends
secured together; at least one of the tubular members comprises;
inner and outer tubes that telescope relative to each other;
external inner tube and outer tube flanges that face one another;
threaded rods extending from the inner tube flange through
apertures in the outer tube flange; a nut that engages each of the
threaded rods to fix a distance between the inner tube and the
outer tube flanges; and a seal between an inner diameter of the
outer tube and an outer diameter of the inner tube.
19. The assembly according to claim 16, wherein: the supply
flowline comprises a plurality of tubular members, each of the
tubular members having un external flange on and end; each of the
tubular members having an internal seal recess at the end, the seal
recesses mating with each other when the flanges are brought toward
each other: a seal located in the seal recess; and a clamp that
bolts around the flanges and draws the flanges toward each
other.
20. The assembly according to claim 16, a wear resistant inlet
passage sleeve that extends from the mounting face of the injection
tee a selected distance into the inlet passage, the inlet passage
sleeve being of a harder material than the injection tee; and a
wear resistant injection tee bore sleeve positioned at a junction
of the injection tee bore with the flow bore, the injection tee
bore sleeve having a greater hardness than the injection tee.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to provisional application
62/105/355, tiled Jan. 20, 2015.
FIELD OF THE DISCLOSURE
[0002] This disclosure relates in general to equipment used in
hydraulic fracturing operations of hydrocarbon wells, and in
particular, to flowline equipment connecting a high pressure
flowline to a wellhead.
BACKGROUND
[0003] Well hydraulic fracturing equipment includes a frac tree
that mounts to a wellhead. In some types, an injection tee secures
to an upper end of the frac tree. The injection tee has a vertical
bore and inlet passages leading to the injection tee bore.
Flowlines connect high pressure pumps to the inlet passages of the
injection tee for pumping a slurry of frac fluid into the well.
[0004] To achieve desired flow rates, some prior art hydraulic
fracturing systems require two or four 3 inch flowlines connected
to each hydraulic fracturing tree. In such prior art systems, the
flowlines are connected to the frac tree in pairs on opposite sides
of the frac tree through the injection tee. In this way hydraulic
fluid will be injected from both sides of the frac tree
simultaneously in order to balance the forces on the hydraulic
fracturing tree and to provide sufficient flow capacity. The
flowlines are made up of short tubular members secured together.
Each of these flowlines can have 10-20 connections between the
tubular members, meaning for each hydraulic fracturing tree there
can be up to 80 connections that must be made up.
[0005] Often, an inlet passage of the injection tee will intersect
the vertical bore of the injection tee at 90 degrees. In some
instances, multiple inlet passages in the injection tee extend
downward and inward to the injection tee bore. In that instance, a
separate flowline connects to each of the inlet passages of the
injection tee.
[0006] The flowlines leading to the injection tee are typically
made up of tubular members connected by swivel unions. The
flowlines typically have numerous turns with at least three swivel
joints to properly align the pipe in three dimensions. Each turn
and swivel joint introduces risks such as, for example, the risk of
the connection failing or the pipe being eroded.
[0007] Rigid connections between the flowline tubular members for
frac operations are known. In that type of connector, the ends of
the tubular members have hubs that are drawn toward each other by
clamps. Each clamp has two halves that bolt together.
[0008] The sand contained in the frac fluids used during the
hydraulic fracturing can further exacerbate the erosion issues in
injection tees, causing cracks, and lodging within surface
imperfections, making them even more pronounced. In order to reduce
erosion risks, the pressure and flow rate of fluids flowing through
these lines can be limited.
SUMMARY
[0009] A hydraulic fracturing assembly includes a hydraulic
fracturing tree having an axis and adapted to be mourned to a
wellhead of a well with the axis vertical. The frac tree has an
axial flow bore and valves that open and close the flow bore. An
injection tee mounts to the frac tree, the injection tee having an
axial injection tee bore that registers with the axial flow bore. A
single inlet passage in the injection tee extends from a flowline
mounting face on an exterior portion of the injection tee downward
and inward into a junction with the axial flow bore. In one
embodiment, a wear resistant inlet passage sleeve extends from the
mounting face of the injection tee a selected distance into the
inlet passage. The inlet passage sleeve is of a harder material
than the injection tee. A flowline connects to the mounting lace to
deliver fluid into the inlet passage. The flowline has an upward
curved section and an inclined section that joins the curved
section and extends downward and outward away from the injection
tee.
[0010] In one embodiment, the inlet passage has an upward and
outward facing shoulder. The inlet passage sleeve has a lower end
that abuts the shoulder. The shoulder defines an outer portion of
the inlet passage and an inner portion of the inlet passage. The
outer portion has a greater inner diameter than an inner diameter
of the inner portion. The inlet passage sleeve has an inner
diameter that is the same as the inner diameter of the inner
portion. The inlet passage sleeve may have a length less than a
length of the inlet passage and more than one-half a length of the
inlet passage.
[0011] The mounting face for the flowline is flat. The inlet
passage sleeve has an outer portion that protrudes outward past the
mounting face.
[0012] In one embodiment, a wear resistant injection tee bore
sleeve is positioned at a junction of the injection tee bore with
the flow bore. The injection tee bore sleeve has a greater hardness
than the injection tee.
[0013] In one embodiment, a support supports the flowline. The
support has a plurality of legs, some of which may be extensible.
Each leg has a clamp on an upper end that secures to a portion of
the flowline and a base on a lower end for placement on ground. An
anchor stake may extend downward from the base for imbedding in
ground.
[0014] In one embodiment, the flowline comprises a plurality of
pipe joints having ends secured together. At least one of the pipe
joints is extensible in length.
[0015] A brace may have an upper end connected to the injection tee
and a lower end connected to a lower portion of the frac tree. The
brace may be located on an opposite side of the injection tee from
the mounting face.
[0016] The injection tee may have a flow back passage extending
from the injection tee bore outward in a direction opposite from
the mounting face.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] While the invention will be described in connection with
certain embodiments, it will be understood that it is not intended
to limit the invention to those embodiments. On the contrary, it is
intended to cover all alternatives, modifications, and equivalents,
as may be included within the spirit and scope of the invention as
defined by the appended claims.
[0018] FIG. 1 is a section view of a hydraulic fracturing flowline
and tree assembly in accordance with an embodiment of this
disclosure.
[0019] FIG. 2 is a section view of an injection tee of the assembly
of FIG. 1.
[0020] FIG. 3 is a section view of an expansion joint of the
assembly of FIG. 1, shown in a retracted position.
[0021] FIG. 4 is a section view of the expansion joint of FIG. 3,
shown in an extended position.
[0022] FIG. 5 is a perspective view of a manifold and three of the
flowlines of FIG. 1.
DETAILED DESCRIPTION OF THE DISCLOSURE
[0023] The method and system of the present disclosure will now be
described more fully hereinafter with reference to the accompanying
drawings in which certain embodiments are shown. The method and
system of the present disclosure may be in many different forms and
should not be construed as limited to the illustrated embodiments
set forth herein; rather, these embodiments are provided so that
this disclosure will be thorough and complete, and will fully
convey its scope to those skilled in the art. Like numbers refer to
like elements throughout.
[0024] FIG. 1 shows a well fluid injection assembly 11 for
injecting high pressure fluid into well 13 during a hydraulic
fracturing or frac operation. Assembly 11 includes a frac tree 15
that secures to a wellhead 17 at the upper end of well 13. Frac
tree 15 may be conventional, having two or more control valves 19
mounted on top of each other. Frac tree 15 includes a tubular
adapter 21 above valves 19. An injection tee 23 secures to the
upper end of adapter 21.
[0025] Injection tee 23 is a solid metal block having an axial
injection tee bore 25 extending vertically through it coaxial with
a vertical axis 28. Injection tee bore 25 coaxially aligns with a
frac tree flow bore 27 extending through frac tree 15. Injection
tee 23 has a single inlet passage 29 that extends from the exterior
of injection tee 23 downward and inward for delivering well fluid
to injection tee bore 25. Inlet passage 29 may incline at an angle
in the range from 20 to 40 degrees relative to axis 28. Injection
tee bore 25 and inlet passage 29 may be four inches in inner
diameter.
[0026] A swab valve 31 may be mounted to the upper end of injection
tee 23. A flowline 33 connects to inlet passage 29 for delivering
frac fluid. Flowline 33 has an upward curved portion 35 with a
downstream end that joins injection tee 23 at inlet passage 29. An
inclined portion 37, which may be substantially straight, joins the
upstream end of curved portion 35 and extends downward and away
from frac tree 15. The upstream end of inclined portion 37 joins a
horizontal portion 39 of flowline 33, which may be elevated a short
distance above ground 40. The angle of inclination of inclined
portion 37 may vary and is shown to be about 45 degrees relative to
vertical. Flowline 33 may be formed of separate metal tubular
members or pipes coupled together, as discussed subsequently.
Alternately, flowline 33 could be a high pressure hose having
articulating metal components and being of a type used in subsea
applications.
[0027] In this embodiment, a stand 41 supports inclined portion 37
and curved portion 35 of flowline 33. Stand 41 may have various
configurations, and is shown with multiple legs 43. One of the legs
43 supports curved portion 35, another supports inclined portion
37, and another supports horizontal portions 39. At least some of
the legs 43 may be extensible, having telescoping portions 43a, 43b
that lock at a desired length for the leg. Each leg 43 has a clamp
45 on its upper end that secures around flowline 33 to provide
support. Each leg 43 has a base 47 that rests on ground 40. One or
more stakes or anchors 49 can be driven through each base 47 into
ground 40 to provide stability to flowline 33. One or mote eyelets
51 on flowline 33 facilitate a crane lilting flowline 33 into
position. Stand 41 may also have one or more cross members 53
connecting certain ones of the legs 43 to each other to provide
lateral stability.
[0028] The high pressure fluid from flowline 33 will exert a
bending force on frac tree 15 about axis 28. Optionally, a brace 55
may be employed to resist bending movement of frac tree 15. Brace
55 is a metal beam or rod that is parallel with axis 28 and located
on an opposite side of injection tee 23 and use tree 15 from
flowline 33. An upper connector 57 joins an upper end of brace 55,
extends perpendicular to axis 28, and secures to injection tee 23.
A lower connector 59 joins and extends perpendicular to brace 55,
connecting to a lower portion of frac tree 15.
[0029] Injection tee 23 may have a return flow passage 61 for
returning fluid from well 13. Return flow passage 61 joins
injection tee bore 25 and extends to an exterior portion of
injection tee 23 opposite flowline 33. Return flow passage 61 may
be perpendicular to axis 28 and of smaller diameter than inlet
passage 29.
[0030] Referring to FIG. 2, injection tee 23 has a supply line
mounting face 63 formed on its exterior. Supply line mounting face
63 is flat and faces upward and outward relative to axis 28. A
supply line flange type connector 65 bolts flowline 33 to supply
line mounting face 63. Connector 65 forms the downstream end of
flowline 33.
[0031] Inlet passage 29 has an outer portion 67 that extends inward
and downward from supply line mounting lace 63. Inlet passage has
an inner portion 69 of smaller inner diameter than outer portion 67
and which extends to a junction with injection tee bore 25. The
intersection of outer portion 67 and inner portion 69 forms an
upward and outward facing shoulder 71. The length of outer portion
67 in this example is greater than the length of inner portion 69,
measured along an axis of inlet passage 29. Alternately, the
lengths of outer and inner portions 67, 69 could be the same, or
the length of inner portion 69 could be greater than outer portion
67. In this embodiment, the length of outer portion 67 is about
55-60% the overall length of inlet passage 29 measured along its
axis.
[0032] A wear resistant inlet passage sleeve 73 fits in outer
portion 67. The outer diameter of inlet passage sleeve 73 is
substantially the same as the inner diameter of outer portion 67.
The inner diameter of inlet passage sleeve 73 is the same as the
inner diameter of inner passage inner portion 69. The wall
thickness of inlet passage sleeve 73 is approximately the same as
the cross-sectional dimension of shoulder 71. The outer end Of
inlet passage sleeve 73 protrudes a short distance outward past
supply line mounting face 63 and is received in a counterbore 74 in
flowline connector 65. In this embodiment, inlet passage sleeve 73
is not press fit into or otherwise bonded in outer portion 67.
Rather, it is simply dropped into outer portion 67 during assembly
and retained against movement along the axis of inner passage 29 by
a base of connector counterbore 74 contacting the outer end of
inlet passage sleeve 73.
[0033] A wear resistant axial bore sleeve 75 is located in
injection tee bore 25. A lower portion of axial bore sleeve 75 fits
within a counterbore 77 formed in a portion of frac tree flow bore
27 at the upper end of adapter 21. An upper portion of axial bore
sleeve 75 fits within a counterbore 79 formed in the lower end of
injection tee bore 25. The inner diameter of axial bore sleeve 75
is the same as frac tree flow bore 27 and injection tee bore 25.
The outer diameter of axial bore sleeve 75 is approximately the
same as the inner diameters of counterbores 77, 79. In this
example, axial bore sleeve 75 is not press-fit in either
counterbore 77, 79, rather it simply drops in place during assembly
and is retained against axial movement by engagement with the upper
end of counterbore 79 and the lower end of counterbore 77.
[0034] The upper end of axial bore sleeve 75 is spaced a short
distance below the junction of inlet passage 29 with injection tee
bore 25. In this embodiment, there is no wear resistant coating or
sleeve in the portion of tee bore 25 from axial bore sleeve 75 to
the junction with inlet passage 29. In this embodiment, there is no
wear resistant coating or sleeve in inlet passage inner portion 69,
Inner passage sleeve 73 and axial bore sleeve 75 are formed of
materials that are harder and more wear resistant than the material
of injection tee 23. The materials may vary and could be hardened
steel or tungsten carbide.
[0035] FIG. 2 shows a return line mounting face 81 on the exterior
of injection tee 23. Return line mounting face 81 may be on an
opposite side of injection tee 23 from supply line mounting face
63. Return line mounting face 81 may be normal to the axis of
return flow passage 61, which in this example is perpendicular to
axis 28. A flange type return line connector 83 on an end of a
return line (not shown) bolts to return line mounting face 81.
Injection tee 23 has a flat upper end, on which swab valve 31 (FIG.
1) mounts, and a flat lower end, which mounts on adapter 21. There
are no other mounting faces on injection tee 23, other then the
flat upper and lower ends and mounting faces 63, 81.
[0036] FIGS. 3 and 4 illustrate a tubular extensible member 85 that
forms a part of flowline 33 (FIG. 1). Flowline 33 may have more
than one extensible members 85, and they may be placed at different
points in flowline 33. Extensible member 85 includes an inner tube
87 that telescopes within an outer rube 89 between a retracted
position shown in FIG. 3 and an extended position shown in FIG. 4.
Outer tube 89 has an internal annular shoulder 90 with a groove
that retains a seal 91. Seal 91 seals against the outer diameter of
inner tube 87. Except at seal 91, an annular clearance 92 exists
between the outer diameter of inner tube 87 and the inner diameter
of outer tube 89. A plurality of stops 94 on the internal end of
inner tube 87 protrude radially outward from the outer diameter of
inner tube 87 to limit the movement of inner and outer tubes 87, 89
apart from each other. Stops 94 contact shoulder 90 when extensible
member 85 fully extends.
[0037] Inner tube 87 has an external flange 93 on its external end
that may be integral with inner tube 87, as shown, or secured
otherwise. Outer tube 89 has an external flange 95 on its external
end. In this example, outer tube flange 95 secures to outer tube 89
by threads 97. A number of threaded rods 99, which are secured to
inner tube flange 93, extend through apertures 101 in outer tube
flange 95. A nut 103 threads onto each rod 99 and bears against a
side of outer tube flange 95 to fix a desired length for extensible
member 85. The abutment of nuts 103 with outer tube flange 95 fixes
the amount of extension of extensible member 85. In this example,
there are no devices, such as nuts 103, to prevent contracting
movement from the fully extended position of FIG. 4. The internal
fluid pressure while pumping frac fluid will prevent extensible
member 85 from contraction.
[0038] In one embodiment, the connections of the tubular members of
flowline 33 are rigid. Once connected, the tubular members cannot
swivel or rotate relative to one another. For example, FIGS. 3 and
4 show an external hub 105 on the external end of inner tube 87 and
also on the external end of outer tube 89. Hub 105 is an external
flange with a tapered shoulder 106 on one side and a flat face 108
on the other side. Mating seal recesses 107 are located in the
inner diameters of hubs 105. A seat 109, which may be metal,
elastomeric or a combination, fits within mating recesses 107. A
clamp 111 (shown only in FIG. 3) formed in two halves fits around
mating hubs 105. When bolts (not shown) extending through bolt
holes 113 are tightened, the halves of clamp 111 engage tapered
shoulders 106 and draw hubs 105 toward each other, causing seal 109
to set. Normally, a slight clearance exists between faces 108 when
clamp 113 is fully tightened. The hub 105 and clamp 111 connections
illustrated in FIG. 3 may be used with all of the tubular members
of flowline 33, whether extensible or not.
[0039] FIG. 5 illustrates a manifold 115 that may be used to direct
high pressure frac fluid from several pumps (not shown) to several
wells. A supply line 117 of high pressure fluid flows into manifold
115 and out several flowlines 33 (three shown). An upstream end of
each flowline 33 connects to a multiple port connector of manifold
115. Each flowline 33 has an injection tee 23 that connects to a
frac tree 15 (FIG. 1).
[0040] In use, technicians will assemble injection assembly 11 as
illustrated in FIG. 1. Extensible members 85 (FIG. 3) may be used
and adjusted in length to align injection tee 23 with frac tree 15.
High pressure pumps then pump a slurry of frac fluid through
flowline 33 and into one or more injection tees 23. The pressures
may exceed 10,000 psi and the flow rates are quite high. The frac
fluid flows through inlet passage 29 of each injection tee 23 down
frac tree flow bore 27 and into well 13. At a certain point, the
operator ceases to pump the frac fluid and allows some of the fluid
in well 13 to flow back through return flow passage 61.
[0041] It is to be further understood that the scope of the present
disclosure is not limited to the exact details of construction,
operation, exact materials, or embodiments shown and described, as
modifications and equivalents will be apparent to one skilled in
the art. In the drawings and specification, there have been
disclosed illustrative embodiments and, although specific terms are
employed, they are used in a generic and descriptive sense only and
not for the purpose of limitation. Accordingly, the improvements
herein described are therefore to be limited only by the scope of
the appended claims.
* * * * *