U.S. patent application number 13/173626 was filed with the patent office on 2012-01-05 for subterranean jetting tool.
This patent application is currently assigned to Dale B. Seekford. Invention is credited to Dale B. Seekford.
Application Number | 20120000674 13/173626 |
Document ID | / |
Family ID | 45398827 |
Filed Date | 2012-01-05 |
United States Patent
Application |
20120000674 |
Kind Code |
A1 |
Seekford; Dale B. |
January 5, 2012 |
Subterranean Jetting Tool
Abstract
The present invention relates to a jetting tool and method
useful for inserting coiled or stick tubing further into
subterranean wells, to permit additional production capacity to be
realized from the well. The tool is located near a distal end of
the tubing and can be used to generate and insertion thrust that
facilitates insertion of the tubing.
Inventors: |
Seekford; Dale B.; (Gloster,
LA) |
Assignee: |
Seekford; Dale B.
Gloster
LA
|
Family ID: |
45398827 |
Appl. No.: |
13/173626 |
Filed: |
June 30, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61359978 |
Jun 30, 2010 |
|
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Current U.S.
Class: |
166/381 ;
166/185; 166/222 |
Current CPC
Class: |
E21B 23/04 20130101;
E21B 23/001 20200501 |
Class at
Publication: |
166/381 ;
166/222; 166/185 |
International
Class: |
E21B 23/00 20060101
E21B023/00; E21B 43/00 20060101 E21B043/00 |
Claims
1. A jetting tool for inserting a tubing work string into a
subterranean well, the jetting tool sized for insertion into the
subterranean well and comprising: a generally cylindrical body
having a proximal and a distal end, the distal end of the jetting
tool for insertion into the subterranean well, the proximal end
configured for attachment to the tubing work string; an interior
supply channel within the body, the interior supply channel
configured to receive a flow from the tubing work string; and a
plurality of jets disposed at an exterior surface of the generally
cylindrical body, the jets configured to receive the flow from the
interior channel of the jetting tool, the plurality of jets angled
to impart an insertion thrust to the tubing work string in the
distal direction when a flow from the interior channel of the
jetting tool exits the plurality of jets in a direction toward the
tubing work string.
2. The jetting tool of claim 1 wherein the jets have a discharge
angle of between about 15 and 35 degrees.
3. The jetting tool of claim 1 wherein the plurality of jets
consists of between about 4 and about 8 jets.
4. The jetting tool of claim 1 wherein an outer diameter of the
body of the jetting tool is nominally between about 2 and about 4
inches.
5. The jetting tool of claim 5 wherein the inside diameter of the
jets is between about 1/8 and 1/2 inch.
6. The jetting tool of claim 1 wherein the jets have an inside
diameter of not more than about 3/8 of an inch.
7. The jetting tool of claim 1 wherein the distal end of the
jetting tool is configured for attachment to a perforating gun.
8. The jetting tool of claim 1 wherein the jets are arranged in two
rows.
9. The jetting tool of claim 8 wherein each row has four jets.
10. A method of facilitating the insertion of a tubing work string
into a subterranean well, the method including the steps of:
positioning a jetting tool at or near a distal end of the tubing
work string; inserting the distal end of the tubing work string
through a surface well control head of the subterranean well;
establishing a flow through the tubing work string into an interior
of the jetting tool, such that the flow discharges the exterior of
the jetting tool through a plurality of jets in the jetting tool;
directing the discharge flow from the plurality of jets of the
jetting tool towards the surface well control head, thereby
producing an insertion thrust that further advances the tubing work
string into the subterranean well.
11. The method of claim 10 wherein a flow of about 3 barrels/minute
of flow establishes a thrust of about 4800 lb/square foot.
12. The method of claim 11 wherein the flow is between about 0.5
and 5 barrels per minute.
13. The method of claim 10 wherein a discharge velocity of the flow
is between about 20 and 60 feet per second.
14. The method of claim 10 wherein a discharge velocity of the flow
is at least about 60 feet per second.
15. The method of claim 10 wherein use of the jetting tool
overcomes sufficient frictional resistance to enable at least an
additional 5 to 15% of additional tubing work string length to be
inserted into the subterranean well.
16. A ported nipple for an in-ground production well, the ported
nipple configured to be mounted at a distal end of a tubing work
string, the ported nipple including discharge jets, the improvement
comprising: angling the discharge jets at an angle of between 15
and 35 degrees toward a surface well control head of the production
well, such that a flow exiting the discharge jets imparts an
insertion thrust to the tubing work string.
Description
RELATED APPLICATIONS
[0001] This application claims benefit of and priority to U.S.
provisional application Ser. No. 61/359,978, filed Jun. 30, 2010,
the entire contents of which are incorporated herein by
reference.
FIELD OF THE INVENTION
[0002] The present invention relates to devices and methods for
conveying a tubing work string, such as coiled tubing or stick pipe
further into production or other subterranean wells, and in
particular into lengthy and horizontal wells.
BACKGROUND
[0003] Subterranean wells, such as oil and gas production wells,
can be very deep and long extending, e.g., 12,000 feet underground.
A production zone in such a vertical well might be only a few
hundred feet in length or vertical height.
[0004] Some production wells, e.g., wells in the Haynesville Shale
area of Louisiana, can be 8,000 to 12,000 feet deep followed by,
e.g., 5,000 to 10,000 feet of additional horizontal run.
[0005] When setting a well up for production, tubing is inserted
into the well, and sometimes into a well casing. Coiled tubing is
commonly used for this purpose. A ported sub (also known as a
ported nipple) is mounted at the end of the tubing, through which
fluid is pumped as the tubing is inserted into the well. As the
tubing is inserted into the well the fluid is pumped into the
tubing, travels to the ported sub, and is generally discharged from
ports in the ported sub in a transverse direction, i.e., in a
direction that is at a right angle to the longitudinal axes of the
tubing and/or the casing. The discharged fluid then returns to the
surface via the annular space between the outside of the tubing and
the inside of the well or casing.
[0006] When coiled tubing is used, the coiled tubing (pipe) is
unrolled from a spool. As long lengths of the tubing are inserted
into the straight well or casing, friction develops between the
external walls of the tubing and the internal wall of the casing.
This friction can cause the tubing to buckle as long lengths are
inserted. Additionally, radial rotation of the tubing to eliminate
or prevent the buckling is not practical since in the case of
coiled tubing the tubing is mounted on a supply spool, and rotating
the spool for this purpose is not readily achievable.
[0007] Substantial friction is also developed as straight tubing
(stick pipe) is inserted into long horizontal runs.
[0008] However, in many wells merely pumping the fluid down the
tubing is insufficient to prevent buckling of the tubing when the
tubing runs are very long, even when the fluid includes friction
reducers, glass beads, and the like, in an attempt to free the
tube. In such situations, when the tubing cannot be inserted
sufficiently near the bottom or end of the casing, lost production
opportunities result as reserves near the far end of the casing
cannot be produced by the well.
[0009] What is needed are devices and techniques to permit tubing,
such as coiled tubing, to be further inserted into the casing of
lengthy production wells so additional reserves can be
produced.
SUMMARY OF THE INVENTION
[0010] The present invention includes a jetting tool that can be
mounted at a distal end (the far end, or lower end) of the tubing
to further draw the tubing into the well. The jetting tool includes
ports that have their discharge angled back towards the entrance of
the well. The amount of angle is chosen to maximize the amount of
downward thrust generated by the jetting tool, so it can assist
with pulling the tubing further into the casing. Preferably the
jetting tool has between four and eight jets, each directed toward
the well head. The amount of fluid being pumped down the tubing can
be about 2 barrels (bbl) per minute, with a differential pressure
of about 400 to 500 psi (e.g., as measured at the surface). This
amount can be varied to change the amount of insertion thrust
provided. For example, flow rates up to about 10 bbl/minute can be
used. This flow provides thrust that helps pull the tubing
straight, assists in overcoming frictional force between the tubing
and the casing, and helps move the tubing further into the
well.
[0011] One aspect of the invention features a jetting tool for
inserting a tubing work string into a subterranean well, such as a
hydrocarbon production well. The jetting tool is sized for
insertion into the well and has a generally cylindrical body. The
body has a proximal and a distal end, the distal end of the tool
for insertion into the subterranean well, followed by the proximal
end. The proximal end is configured to be attached to a tubing work
string, such as coiled tubing or stick tubing.
[0012] The jetting sub can have an interior supply channel within
the body that is configured to receive a flow, e.g., from the
tubing work string. It can also have a plurality of jets located at
an exterior surface of the body, the jets being configured to
receive the flow from the interior channel and angled to impart an
insertion thrust to the tubing work string. The discharge flow from
the jets creates the insertion thrust.
[0013] The jets of the jetting tool can have a discharge angle J of
between about 15 and 35 degrees, and there can be between about 4
and about 8 discharge jets on the jetting tool.
[0014] The outer body of the jetting tool can have an outer
diameter of between about 2 and about 4 inches. An inside diameter
of the jets can be between about 1/8 and 1/2 inch, or about 3/8 of
an inch. It can have between about 4 and 8 jets, and they can be
configured in one row, or more than one row (e.g., two rows having
four jets each). An embodiment has one row of six jets, having and
inside diameter of 3/8 of an inch. The distal end of the jetting
tool can be attached to a perforating gun, and the proximal end can
be attached to a tubing work string, e.g., that provides the flow
to the jetting tool.
[0015] The invention also includes a method of inserting a tubing
work string into a subterranean well through a surface well control
head, such as a well head or a blow out preventer (BOP). The method
facilitates insertion of a tubing work string into a subterranean
well. It includes the steps of positioning a jetting tool near a
distal end of a tubing work string, inserting the tubing work
string through a surface well control head of the subterranean well
(such as a BOP), and establishing a flow through the tubing into an
interior of the jetting tool, such that the flow discharges the
exterior of the jetting tool through a plurality of jets in the
jetting tool.
[0016] A discharge flow from the plurality of jets of the jetting
tool is directed towards the surface well control head, thereby
producing an insertion thrust that further advances the tubing work
string into the subterranean well. The flow can be about 3
barrels/minute, which establishes a thrust of about 4800 lb/square
foot. The flow can be from about 0.5 to 5 barrels per minute, or
more, depending upon the needs of the well and the design
parameters of the jetting tool (such as size and number of jets). A
discharge velocity of the flow can be between about 20 to 60 feet
per second, or more, depending upon the design conditions chosen
for the well. It is possible to use more than one jetting tool for
a well application, and the jetting tool can be machined from a
combination of parts that are subsequently assembled.
[0017] Use of this method can overcome sufficient frictional
resistance to enable at least an additional 5 to 15% of additional
tubing work string length to be inserted into the subterranean
well.
[0018] Another aspect of the invention includes a ported nipple for
an in-ground production well, the ported nipple configured to be
mounted at a distal end of a tubing work string, and including
discharge jets. The improvement of the ported nipple includes
angling the discharge jets at an angle of between 15 and 35 degrees
toward a surface well control head of the production well, such
that a flow exiting the discharge jets imparts an insertion thrust
to the tubing work string.
SUMMARY OF THE FIGURE
[0019] The foregoing discussion will be understood more readily
from the following detailed description of the invention, when
taken in conjunction with the accompanying drawings.
[0020] FIG. 1 is a cross-sectional view of a subterranean well.
[0021] FIG. 2 shows a demonstration of fluid being discharged
through the ports of a jetting tool.
[0022] FIG. 3 is a close-up view of a jetting tool according to an
embodiment of the invention.
[0023] FIG. 4 is a cross-sectional view of an embodiment of the
jetting tool.
[0024] FIG. 5 shows an end view of an embodiment of a jetting tool,
which depicts a thread connection for mating directly with coiled
tubing, without the need of a crossover (adapter).
DETAILED DESCRIPTION
[0025] FIG. 1 is a cross-sectional view of a subterranean well. As
explained in Example 1 below, such wells can be 12,000 feet deep
and have a horizontal run of 5,000 feet. A perforating gun 105 can
be near the end of the tubing work string, attached to a jetting
tool 100.
[0026] FIG. 2 shows a demonstration of fluid being discharged
through the ports of a jetting tool 100. Depicted at a distal end
of the jetting tool 100 is a perforating gun 105. In some
embodiments the perforating gun is replaced with a plug, such as a
bull plug (not shown). An insertion thrust 125 is provided by a
flow of fluid from a tubing working string (not shown), that
supplies the flow to a proximal end of the jetting tool.
[0027] FIG. 3 is a close-up view of a jetting tool 100 according to
an embodiment of the invention. The jetting tool can have a
generally cylindrical body 200 with an OD, e.g., of 2'' to 3''
(nominal). The jetting tool at the proximal end P is connected to
the tubing, and can be machined to have threads that correspond
with and mate to the threads of the tubing, such as a 23/8'' PAC
thread box. The other, distal end D of the jetting tool can have a
common bull plug thread such that it can be connected directly to a
perforating gun 105. Alternatively, the second end of the jetting
tool can be threaded, e.g., having a 23/8'' 8rd (8 round) thread
pin.
[0028] The jets 225 in the jetting tool can have machined ports
that extend inwardly toward the ID of the tool at the pin connector
end. These ports are steeply angled at an angle J (e.g., 15 to 35
degrees from the longitudinal axis 250 of the jetting tool) toward
the proximal end P to maximize downward thrust imparted to the
tubing work string. More than one row of jets can be included about
the circumference of the body, although only one row is
depicted.
[0029] The tubing can be, e.g., 1.25 to 23/8''. A perforating gun
mounted below the jetting tool can have a diameter, e.g., of 2.125
to 3.375'', so substantial friction can also be developed between
the outside surface of the gun and the inside surface of the
casing.
[0030] FIG. 4 is a cross-sectional view of an embodiment of the
jetting tool of FIG. 3. A plurality of jets 225 (only one is shown)
can receive a flow from an interior flow channel 350. The flow is
then discharged through the plurality of jets at an angle J,
thereby creating a downward insertion force due to the insertion
thrust that is generated by the discharge flow.
[0031] FIG. 5 shows an end view of an embodiment of a jetting tool,
which depicts a thread connection 305 for mating directly with
coiled tubing, without the need of a crossover (adapter). An
interior flow channel 350 is depicted, through which a flow can
enter the jetting tool at the proximal end P, before discharge of
the flow through the jets 225 towards the proximal end P of the
jetting tool. As shown, a bracket 360 supports the jetting sub at a
distal end D of the jetting sub, before insertion into a well.
Example 1
[0032] When running TCP (tubing conveyed perforation) guns on
coiled tubing, or regular tubing (stick pipe) in long horizontal
runs, large amounts of friction are created as the tubing is used
to push the tools toward the bottom of the well. This friction
causes the tubing to buckle and "stack out," such that additional
tubing cannot be inserted into the well.
[0033] During the process fluid is constantly pumped down the
tubing and circulates back to the surface on the outside of the
tubing. This energy is available and can be used advantageously.
This concept was tested in November, 2009 on a natural gas
production well in the Haynesville Shale field in Louisiana. The
well had been drilled to about 12,000 feet true vertical depth,
followed by a horizontal run of an additional about 5,000 feet. The
horizontal run is used to produce additional gas in the section, as
it approaches the boundary of the next section (of land).
[0034] A producing section in wells in this field can vary from
about 300 to 800 feet of casing length. Thus, after perforation is
complete, the horizontal portion of the well can have the
production capability of 10 to 20 vertical wells.
[0035] For the test on this particular production well, the tubing
could not inserted beyond a length of 16,000 feet due to
buckling/friction of the tubing work string within the casing.
Another 550 feet of production length remained at the far end of
the casing, into which the tubing could not be inserted. When a
jetting tool using the present invention was installed on the
tubing (between the end of the tubing and the perforating guns)
insertion of the tubing for the additional 550 feet was achieved,
representing a total insertion length of between 16,500 and 17,000
feet. The extra 550 of tubing insertion represents the production
capacity of an additional vertical production well, offsetting
substantial additional drilling costs to permit production of this
portion of the gas field.
Example 2
[0036] Testing has shown that for a jetting tool with six jets
having jet inside diameters of 3/8 of an inch, a flow of 1 barrel
per minute generates a thrust of about 670 lbs/square foot. Two
barrels/min generates a thrust of about 2100 lb/square foot, and 3
barrels/min generates a thrust of about 4800 lb/square foot. In
this embodiment, a flow of 1 bbl/min corresponds to a discharge
velocity of about 20 feet per second from the jets. A flow of three
bbl/min corresponds to a discharge flow of about 60 fps. These
large insertion forces are responsible for obtaining the types of
results exemplified above.
[0037] The invention is useful for all types of subterranean wells,
including wells being drilled that do not have a casing installed,
and for wells for producing non-hydrocarbon products, such as water
or hot water.
[0038] While the invention has been particularly shown and
described with reference to specific preferred embodiments, it
should be understood by those skilled in the art that various
changes in form and detail may be made wherein without departing
from the spirit and scope of the invention.
* * * * *