U.S. patent application number 17/376252 was filed with the patent office on 2021-11-04 for zipper bridge.
This patent application is currently assigned to OIL STATES ENERGY SERVICES, L.L.C.. The applicant listed for this patent is OIL STATES ENERGY SERVICES, L.L.C.. Invention is credited to Danny L. Artherholt, Charles Beedy, Mickey Claxton, Bob McGuire, Blake Mullins, Richard Brian Sizemore.
Application Number | 20210340852 17/376252 |
Document ID | / |
Family ID | 1000005720395 |
Filed Date | 2021-11-04 |
United States Patent
Application |
20210340852 |
Kind Code |
A1 |
Sizemore; Richard Brian ; et
al. |
November 4, 2021 |
ZIPPER BRIDGE
Abstract
A frac zipper manifold bridge connector comprises two bridge
spools for connecting a well configuration unit of a frac zipper
manifold to a frac tree of a wellhead. The connector comprises
multiple connections involving threaded flanges, such that the
orientation of the bridge spools may be adjusted to ensure that
they are correctly aligned with the frac tree.
Inventors: |
Sizemore; Richard Brian;
(White Oak, TX) ; McGuire; Bob; (Meridian, OK)
; Artherholt; Danny L.; (Asher, OK) ; Claxton;
Mickey; (Oklahoma City, OK) ; Mullins; Blake;
(Edmond, OK) ; Beedy; Charles; (Oklahoma City,
OK) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
OIL STATES ENERGY SERVICES, L.L.C. |
Houston |
TX |
US |
|
|
Assignee: |
OIL STATES ENERGY SERVICES,
L.L.C.
Houston
TX
|
Family ID: |
1000005720395 |
Appl. No.: |
17/376252 |
Filed: |
July 15, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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16702301 |
Dec 3, 2019 |
11091993 |
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17376252 |
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16443639 |
Jun 17, 2019 |
10570692 |
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16702301 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E21B 43/267 20130101;
F17D 5/00 20130101; E21B 43/2607 20200501; G05D 7/0641
20130101 |
International
Class: |
E21B 43/26 20060101
E21B043/26; F17D 5/00 20060101 F17D005/00; E21B 43/267 20060101
E21B043/267; G05D 7/06 20060101 G05D007/06 |
Claims
1. A bridge connector for a frac zipper manifold, comprising: a
bridge connector header comprising an axial throughbore and a
separate input in fluid communication with the throughbore; first
and second connection blocks in fluid communication with the axial
throughbore of the bridge connector header; and first and second
bridge spools attached to, and in fluid communication with, the
first and second connection blocks respectively.
2. The bridge connector of claim 1, further comprising a first
spool in fluid communication with the input of the bridge connector
header.
3. The bridge connector of claim 2, wherein the first spool is
attached to the bridge connector header by a threaded flange.
4. The bridge connector of claim 1, further comprising second and
third spools, each of which is in fluid communication with one end
of the axial throughbore of the bridge connector header, and both
of which are attached to the bridge connector header by a threaded
flange.
5. The bridge connector of claim 4, whether the first connection
block is attached to the second spool by a threaded flange and the
second connection block is attached to the third spool by a
threaded flange.
6. A method for installing a bridge connector for a frac zipper
manifold, comprising the following steps: providing a frac zipper
manifold comprising: a spool configured to allow axial flow of
fracturing fluid; and an outlet configured to selectively allow
flow of fracturing fluid to the bridge connector; providing a
bridge connector header comprising an axial throughbore and a
separate input in fluid communication with the throughbore;
configuring the bridge connector header such that the input is in
fluid communication with the outlet of the frac zipper manifold;
configuring first and second connection blocks such that they are
in fluid communication with the axial throughbore of the bridge
connector header; and attaching first and second bridge spools to
the first and second connection blocks respectively.
7. The method of claim 6, wherein the step of configuring the
bridge connector header comprises attaching a first spool in fluid
communication with both the input of the bridge connector header
and the outlet of the frac zipper manifold.
8. The method of claim 7, wherein a threaded flange is used to
attach the first spool to the bridge connector header.
9. The method of claim 9, wherein the bridge connector header is
rotated around a central axis of the first spool.
10. The method of claim 6, wherein the step of configuring the
first and second connection blocks comprises attaching a second
spool between the first connection block and the bridge connector
header and attaching a third spool between the second connection
block and the bridge connector header.
11. The method of claim 10, wherein threaded flanges are used to
attach the second spool to the first connection block and the third
spool to the second connection block.
12. The method of claim 11, wherein the first and second bridge
spools are rotated around a central axis of the second and third
spools.
Description
TECHNICAL FIELD
[0001] The present disclosure relates generally to oil or gas
wellbore equipment, and, more particularly, to a connector bridge
for a frac manifold.
BACKGROUND
[0002] Frac manifolds, also referred to herein as zipper manifolds,
are designed to allow hydraulic fracturing operations on multiple
wells using a single frac pump output source. Frac manifolds are
positioned between the frac pump output and frac trees of
individual wells. A frac manifold system receives fracturing fluid
from the pump output and directs it to one of many frac trees.
Fracturing fluid flow is traditionally controlled by operating
valves to isolate output to a single tree for fracking
operations.
[0003] Frac zipper manifolds may be rigged up to frac trees before
frac equipment arrives at the well site. Once onsite, the frac
equipment need only be connected to the input of the frac manifold.
Because individual frac trees do not need to be rigged up and down
for each fracking stage and because the same frac equipment can be
used for fracking operations on multiple wells, zipper manifolds
reduce downtime for fracking operations while also increasing
safety and productivity. Another benefit includes reducing
equipment clutter at a well site.
[0004] Despite their benefits, further efficiencies and cost
savings for zipper manifolds may be gained through improved
designs. In particular, typically treatment fluid in the zipper
manifold passes to frac trees via goat heads or frac heads and frac
iron, but there are several drawbacks to using such setups to span
the distance between the zipper manifold and each frac tree. Goat
heads, or frac heads, traditionally employ multiple downlines and
restraints that clutter the area between the zipper manifold and
the frac tree, which can make for a more difficult and less safe
work environment to operate and maintain the frac equipment.
[0005] Some designs have been developed to avoid using frac iron.
One design uses a single line made from studded elbow blocks and
flow spools with swiveling flanges. Such a design is disclosed in,
for example, U.S. Pat. Nos. 9,932,800, 9,518,430, and 9,068,450. A
similar design is currently offered for sale by Cameron
International of Houston, Tex., under the brand name Monoline. One
drawback of this design is that the weight of the equipment
combined with the potentially awkward orientation of the lines can
make installation difficult and can place uneven or increased
stress on the connections to the frac manifold and/or the frac
tree. Another drawback is that using a single line to connect the
frac manifold to the frac tree can lead to increased velocity and
turbulence of the flow, when compared to using multiple lines. Such
conditions may lead to a greater risk of erosion in the frac tree.
Replacing a damaged frac tree can be very expensive and
time-consuming. Accordingly, what is needed is an apparatus,
system, or method that addresses one or more of the foregoing
issues related to frac zipper manifolds, among one or more other
issues.
SUMMARY OF THE INVENTION
[0006] The frac zipper manifold uses a dual passage bridge to
connect from a zipper manifold to a frac tree. With this bridge
design, multiple frac iron lines between the zipper manifold and
the frac tree are eliminated while providing for a robust, durable
connection which may be adjusted to accommodate different
configurations of zipper manifolds and frac trees.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] Various embodiments of the present disclosure will be
understood more fully from the detailed description given below and
from the accompanying drawings of various embodiments of the
disclosure. In the drawings, like reference numbers may indicate
identical or functionally similar elements.
[0008] FIG. 1 illustrates a zipper manifold as known in the prior
art.
[0009] FIG. 2 illustrates one embodiment of an improved dual spool
connection from a zipper manifold to a frac tree.
[0010] FIG. 3 illustrates the bridge connector header used in
conjunction with one embodiment of the improved dual spool
connection shown in FIG. 2.
[0011] FIGS. 4A-4E illustrate one method of installing a short
spool and threaded flange on the lower side of a T-junction.
[0012] FIGS. 5A-5E illustrate one method of installing short
spools, threaded flanges, and studded blocks on either side of the
axial throughbore of a T-junction.
[0013] FIGS. 6A-6B illustrate a blind flange that may optionally be
used to add a flow diverter to an improved dual spool connection
from a zipper manifold to a frac tree.
[0014] FIGS. 7A-7B illustrate another blind flange that may
optionally be used to add one or more flow diverters at alternative
points in the improved dual spool connection.
[0015] FIG. 8 illustrates an improved dual spool connection
including both the blind flange of FIGS. 6A-6B and two of the blind
flanges shown in FIGS. 7A-7B.
DETAILED DESCRIPTION
[0016] FIG. 1 illustrates an example of a prior art zipper manifold
100. The manifold may be positioned vertically, as shown in FIG. 1,
or it may be positioned horizontally. The frac manifold 100 can
include two or more well configuration units 101. Each well
configuration unit 101 includes one or more valves 102 and a
connection header 103, and the well configuration units 101 may be
collectively or individually (as shown) positioned on skids 106.
Each connection header 103 connects to a similar header on the frac
tree. Prior art connection headers 103 are often called frac heads
or goat heads and include multiple fluid connection points, as
shown in FIG. 1. Each fluid connection point attaches to a downline
110 that is routed to the ground before turning back up and
connecting to a connection point on the frac tree header 270 of the
frac tree 200. The use of downlines 110 allows operators to adjust
for different distances between and relative locations of the frac
manifold 100. The downlines 110 typically have small diameters,
which limits the flow therethrough. The multiple lines and the
restraints for those lines create clutter between the zipper
manifold and the frac tree, which can make maintenance difficult
and increase safety concerns. Each well configuration unit 101
typically includes a hydraulically actuated valve 102a and a
manually actuated valve 102b. The well configuration units 101 of
the zipper manifold 100 are connected together by zipper spools
104, and the final zipper spool 104 may be capped off or connected
to other well configurations 101 as needed. The zipper manifold 100
connects to the output of the frac pump at the frac supply header
105.
[0017] In operation, the valves 102 of one well configuration unit
101 are opened to allow fluid flow to the corresponding frac tree
200 through its connection header 103 while the valves 102 of other
well configuration units 101 in the zipper manifold 100 are closed.
The valves 102 may be closed and opened to control the flow through
different well configuration units 101 of the zipper manifold
100.
[0018] FIG. 2 illustrates an exemplary embodiment of a well
configuration unit 210 with an improved bridge connector header
230. The bridge connector header 230, which connects to a frac
tree, forms a "T" junction 215 with a short spool extending upward
from valve 102a. The T-junction 215 of the bridge connector header
230 connects to two studded blocks 250. Each studded block 250
joins to a bridge spool 255 that connects similarly to studded
blocks 250 and a frac tree header 270 on the frac tree.
[0019] As shown in more detail in FIG. 3, the bridge connector
header 230 includes threaded flanges 235 on each side of the
"T"--right, left, and bottom--connected via short spools 238. Blind
flange 236 may be connected to the top side of bridge connector
header 230. The threaded flanges 235, which are able to be rotated,
are lined up with a corresponding flange or bolt holes during
install. The threaded flanges 235 engage threads on the outer
surface of the short spools 238, but the external threads include
excess threading to allow for additional rotation of the threaded
flange 235 to allow it to orient to the desired position. For
example, the threaded flange 235 at the bottom of the T is aligned
with a corresponding flange on the well configuration unit 210, and
bolts are used to secure the flanges together. A studded block 250
is similarly joined to each of the right and left sides of the
T-junction of the bridge connector header 230 via a short spool 238
and threaded flanges 235. Blind flange 240 may be connected to the
side of studded block 250 that is opposite threaded flange 235.
[0020] The threaded flanges 235 allow the T-junction of the bridge
connector header 230 and associated parts to be oriented into a
desired configuration before final assembly of the bridge connector
header 230. The threaded flange 235 at the bottom allows the bridge
connector header 230 to be rotated about the central axis of the of
the well configuration unit 210 (indicated in FIG. 2 as the
y-axis), which may also be referred to as azimuthal rotation.
Azimuthal rotation about the y-axis allows the entire T-junction,
along with both bridge spools 255, to be laterally adjusted in
order to accommodate a potential horizontal misalignment between
bridge connection header 230 and frac tree header 270.
[0021] The threaded flanges 235 on the right and left sides of the
T-junction allow bridge spools 255 to be rotated about the central
axis running horizontally through the T-junction (indicated in FIG.
2 as the z-axis), which may also be referred to as vertical
rotation. Vertical rotation about the z-axis allows the distal end
of bridge spools 255 to be adjusted up or down to accommodate a
potential vertical misalignment between bridge connection header
230 and frac tree header 270.
[0022] Internally, the T-junction splits the supply fluid flow to
the two studded blocks 250, which are elbow shaped to route the
flows to the bridge spools 255. The frac fluid travels through the
bridge spools 255 to the studded blocks 250 on the frac tree side,
and the two flows are rejoined at the frac tree header 270 of the
frac tree 200. Significantly, when the two flow streams enter the
frac tree header 270 of the frac tree 200, they enter from opposite
directions. As a result, the velocity vectors of both streams will,
to some degree, cancel each other out. This cancellation effect
results in a lower velocity of the combined flow stream within frac
tree 200, as compared to the velocity that would result from the
use of a single spool connector.
[0023] In simulations performed by the applicant, the configuration
shown in FIG. 2, with each bridge spool having a 5-inch inner
diameter and an overall flow rate of 100 barrels per minute, the
flow velocity in the upper portion of frac tree 200, immediately
below T-junction 290, was in the range of 32-38 feet per
second.
[0024] In a separate simulation, bridge spools 255 were replaced
with a single bridge spool running in a straight line between
bridge connector 230 and frac tree header 270. The single bridge
spool was simulated with an inner diameter of 7 inches, such that
it had the same cross-sectional area as the combination of bridge
spools 255 (49 in.sup.2 vs 50 in.sup.2). At the same simulated rate
of 100 barrels of fluid flow per minute, the flow velocities seen
at the same point within frac tree 200 were significantly higher
than the dual-spool configuration, generally exceeding 38 feet per
second and in certain areas exceeding 45 feet per second.
[0025] The dual-spool configuration shown in FIG. 2 should also
result in lower turbulence of the combined flow stream within frac
tree 200. The lower velocity and lower turbulence should reduce the
risk of erosion within frac tree 200, as compared to a flow stream
within a single spool connector.
[0026] Installation of the improved connector bridge can be
performed in several different ways. In one method, the first step
in the installation process, as shown in FIG. 4A, is to securely
attach lower threaded flange 235 to the top of well configuration
unit 210, just above valve 102a, using bolts 280. Next, as shown in
FIG. 4B, short spool 238 is attached to threaded flange 235 by
rotating short spool 238 until the threaded portion 282 is fully
engaged with the complementary threaded portion 284 of threaded
flange 235. Next, as shown in FIG. 4C, upper threaded flange 235 is
attached to short spool 238 by rotating upper threaded flange 235
until the threaded portion 284 is engaged with the complementary
threaded portion 282 of short spool 238. Next, as shown in FIG. 4D,
upper threaded flange 235 is attached to bridge connector header
230 using bolts 280. At this point, if necessary, bridge connector
header 230 is rotated azimuthally about the y-axis, such that it
aligns correctly with the frac tree to which the bridge spools are
intended to connect. Such azimuthal rotation is accomplished by the
threaded connection between upper threaded flange 235 and short
spool 238, as shown in FIG. 4E. Once bridge connector header 230 is
correctly aligned, all bolts and connections are securely
tightened.
[0027] In this installation method, the next step, as shown in FIG.
5A, is to securely attach an inner threaded flange 235 on either
side of bridge connector header 230, using bolts 280. Next, as
shown in FIG. 5B, a short spool 238 is attached to each threaded
flange 235 by rotating short spool 238 until the threaded portion
282 is fully engaged with the complementary threaded portion 284 of
threaded flange 235. Next, as shown in FIG. 5C, an outer threaded
flange 235 is attached to each short spool 238 by rotating outer
threaded flange 235 until the threaded portion 284 is engaged with
the complementary threaded portion 282 of short spool 238. Next, as
shown in FIG. 5D, each outer threaded flange 235 is attached to a
studded block 250 using bolts 280. At this point, if necessary,
studded blocks 250 are rotated vertically about the z-axis, such
that they align correctly with the studded blocks 250 on the frac
tree to which the bridge spools are intended to connect. Such
vertical rotation is accomplished by the threaded connection
between outer threaded flanges 235 and short spools 238, as shown
in FIG. 5E. Once studded blocks 250 are correctly aligned, all
bolts and connections are securely tightened. During this stage of
the installation process, bridge spools 255 may be attached to
studded blocks 250 either before or after studded blocks 250 are
attached to outer threaded flanges 235.
[0028] In another installation method, the bridge spools 255,
studded blocks 250, bridge connector header 230, and frac tree
header 270 may all be pre-assembled at the well site. A crane is
used to lower the entire assembly onto the well configuration unit
210 and the frac tree 200, where it may be connected. If there are
elevation differences between the bridge connector header 230 and
the frac tree header 270, the rotating threaded flanges 235 may be
used to adjust the elevation at either end.
[0029] The zipper bridge is superior to other methods of connecting
the zipper manifold to the frac trees for multiple reasons. Because
its orientation may be adjusted in one or both of the azimuthal and
vertical directions, it can accommodate variations in the distance
between and configuration of different frac manifolds and frac
trees. Because it comprises two bridge spools, it does not require
the multiple downlines used in many prior art systems. It is easier
to install and more stable than other large-diameter hardline
connections because its design is simpler and does not involve
post-installation adjustments, and also because it is symmetrical
about a line running from the well configuration unit to the frac
tree. Because it comprises two flow lines that enter the frac tree
header from opposite directions, it decreases the risk of erosion
as compared to prior art systems using a single flow line.
[0030] Optionally, the present invention may also include one or
more diverters in the flow stream, as shown in FIG. 6A-8. Referring
to FIG. 6A, an alternative embodiment of blind flange 236 may
include flow diverter 300. As shown in FIG. 8, flow diverter 300
extends downward from blind flange 236, such that it is disposed
within the flow of fracturing fluid from the frac manifold to the
frac tree. Flow diverter 300 may be generally cylindrical with
diverting surfaces 302 and 304. In this configuration, the central
axis of flow diverter 300 may be substantially aligned with the
central axis of short spool 238 which is connected to the bottom
side of bridge connector header 230. This axis is shown as the
y-axis in FIG. 2. Diverting surfaces 302 and 304 may be curvilinear
and are preferably concave, as shown in FIG. 6A. Alternatively,
diverting surfaces 302 and/or 304 may be convex, planar, or any
other configuration. Flow diverter 300 may also comprise more or
less than two diverting surfaces. For example, flow diverter 300
may be generally conical, such that it comprises one continuous
diverting surface. In such a configuration, the generally conical
diverting surface may also be concave, convex, planar, or any other
configuration.
[0031] As fluid flows up through short spool 238 and into bridge
connector header 230, the flow is along the y-axis, such that it is
orthogonal to the z-axis, which passes through short spools 238
that lead away from bridge connector header 230 and towards studded
blocks 250. As a result, the flow has a tendency to become
turbulent as it shifts from the y-axis to the z-axis. This
turbulence, as well as other dynamic flow characteristics of this
configuration, can lead to increased erosion and premature failure
of bridge connector header 230 and short spools 238.
[0032] With the installation of the alternative embodiment of blind
flange 236 shown in FIG. 6A, the flow up through short spool 238
and into bridge connector header 230 will impact diverting surfaces
302 and 304. Diverting surfaces 302 and 304 will generally redirect
a portion of the flow to from the y-axis to the z-axis. This
redirection may decrease the turbulence of the flow as it shifts
from the y-axis to the z-axis, and thus decrease the erosion of
bridge connection header 230 and short spools 238.
[0033] Referring now to FIG. 7A-7B, either or both blind flange 240
may include flow diverter 310, with diverting surface 312. Flow
diverter 310 may be generally cylindrical with a central axis along
the z-axis, as shown in FIG. 2. Diverting surface 312 may be
curvilinear and is preferably concave. Alternatively, diverting
surface may be convex, planar, or any other configuration. Flow
diverter 310 may also have a plurality of diverting surfaces.
[0034] As fluid flows through short spools 238 and into studded
blocks 250, it again shifts direction, this time from the z-axis to
the x-axis, which is coaxial with bridge spools 255. This
transition will also cause turbulence and thus the potential for
erosion within studded blocks 250. With the use of the alternative
embodiment of blind flange 240, as shown in FIG. 7A-7B, the flow
along the z-axis will impact diverting surface 312, which will
redirect a portion of the flow from the z-axis to the x-axis, and
thus decrease the erosion of studded blocks 250.
[0035] Although flow diverters 300 and 310 may also experience
erosion, replacement of blind flanges 236 and 240 is much easier
and less expensive than replacing bridge connector header 230,
short spools 238, and/or studded blocks 250.
[0036] It is understood that variations may be made in the
foregoing without departing from the scope of the present
disclosure. In several exemplary embodiments, the elements and
teachings of the various illustrative exemplary embodiments may be
combined in whole or in part in some or all of the illustrative
exemplary embodiments. In addition, one or more of the elements and
teachings of the various illustrative exemplary embodiments may be
omitted, at least in part, and/or combined, at least in part, with
one or more of the other elements and teachings of the various
illustrative embodiments.
[0037] Any spatial references, such as, for example, "upper,"
"lower," "above," "below," "between," "bottom," "vertical,"
"horizontal," "angular," "upwards," "downwards," "side-to-side,"
"left-to-right," "right-to-left," "top-to-bottom," "bottom-to-top,"
"top," "bottom," "bottom-up," "top-down," etc., are for the purpose
of illustration only and do not limit the specific orientation or
location of the structure described above.
[0038] In several exemplary embodiments, while different steps,
processes, and procedures are described as appearing as distinct
acts, one or more of the steps, one or more of the processes,
and/or one or more of the procedures may also be performed in
different orders, simultaneously and/or sequentially. In several
exemplary embodiments, the steps, processes, and/or procedures may
be merged into one or more steps, processes and/or procedures.
[0039] 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.
[0040] 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, any 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.
Moreover, it is the express intention of the applicant not to
invoke 35 U.S.C. .sctn. 112, paragraph 6 for any limitations of any
of the claims herein, except for those in which the claim expressly
uses the word "means" together with an associated function.
* * * * *