U.S. patent application number 10/837953 was filed with the patent office on 2005-11-03 for tubing/casing connection for u-tube wells.
Invention is credited to McGlothen, Jody R., Restarick, Henry L..
Application Number | 20050241834 10/837953 |
Document ID | / |
Family ID | 35185910 |
Filed Date | 2005-11-03 |
United States Patent
Application |
20050241834 |
Kind Code |
A1 |
McGlothen, Jody R. ; et
al. |
November 3, 2005 |
Tubing/casing connection for U-tube wells
Abstract
A tubing/casing connection for U-tube wells. In a described
embodiment, a tubular string connection system includes a first
tubular string having an expanded entry guide; and a second tubular
string having an end guided into the first tubular string by the
entry guide.
Inventors: |
McGlothen, Jody R.;
(Waxahachie, TX) ; Restarick, Henry L.;
(Carrollton, TX) |
Correspondence
Address: |
KONNEKER & SMITH P. C.
660 NORTH CENTRAL EXPRESSWAY
SUITE 230
PLANO
TX
75074
US
|
Family ID: |
35185910 |
Appl. No.: |
10/837953 |
Filed: |
May 3, 2004 |
Current U.S.
Class: |
166/380 ;
166/241.1 |
Current CPC
Class: |
E21B 41/0035 20130101;
E21B 43/10 20130101; E21B 43/305 20130101 |
Class at
Publication: |
166/380 ;
166/241.1 |
International
Class: |
E21B 007/06 |
Claims
What is claimed is:
1. A tubular string connection system, comprising: a first tubular
string having an expanded entry guide; and a second tubular string
having an end guided into the first tubular string by the entry
guide.
2. The system of claim 1, wherein the first tubular string is
positioned in a first wellbore, and the second tubular string is
positioned in a second wellbore.
3. The system of claim 1, wherein the entry guide includes at least
one inclined surface for guiding the second tubular string into the
first tubular string.
4. The system of claim 3, wherein the inclined surface is an
external surface on an outer end of the entry guide.
5. The system of claim 3, wherein the inclined surface is an
interior surface of the entry guide.
6. The system of claim 1, wherein the entry guide is expanded by
applying a pressure differential across a wall of the entry
guide.
7. The system of claim 1, wherein the entry guide is expanded by
inflating a membrane within the entry guide.
8. The system of claim 1, wherein an outer end wall of the expanded
entry guide is cut through from an interior to an exterior of the
entry guide.
9. The system of claim 1, wherein an outer end wall of the expanded
entry guide is cut through from an exterior to an interior of the
entry guide.
10. The system of claim 1, wherein the second tubular string
includes a sheath protecting a seal on the second tubular string,
the sheath displacing to uncover the seal when the second tubular
string engages the expanded entry guide.
11. A method of connecting first and second tubular strings in a
well, the method comprising the steps of: providing an expandable
entry guide on the first tubular string; positioning the entry
guide in the well, and then expanding the entry guide; and guiding
the second tubular string into the first tubular string.
12. The method of claim 11, wherein the providing step further
comprises providing an inclined surface on the entry guide, and
wherein the guiding step further comprises using the inclined
surface to guide the second tubular string into the first tubular
string.
13. The method of claim 11, wherein the guiding step further
comprises releasing a protective sheath to thereby uncover a seal
on the second tubular string.
14. The method of claim 13, further comprising the step of
sealingly engaging the seal within the first tubular string,
thereby providing sealed communication between the first and second
tubular strings.
15. The method of claim 13, wherein the releasing step further
comprises releasing the sheath from a latch carried on the second
tubular string.
16. The method of claim 15, further comprising the step of engaging
the latch with a profile in the first tubular string, thereby
securing the second tubular string to the first tubular string.
17. The method of claim 11, further comprising the step of securing
the second tubular string to the first tubular string.
18. The method of claim 17, wherein the securing step further
comprises engaging a profile formed within the first tubular
string.
19. The method of claim 18, wherein in the profile engaging step,
the profile is formed within the entry guide.
20. The method of claim 17, wherein the securing step further
comprises expanding the second tubular string within the first
tubular string.
21. The method of claim 17, wherein the securing step further
comprises engaging a latch on the second tubular string with the
first tubular string.
22. The method of claim 17, wherein the securing step further
comprises engaging a latch with a profile.
23. The method of claim 11, further comprising the step of cutting
through an outer end wall of the entry guide.
24. The method of claim 23, wherein the cutting step further
comprises guiding a cutting tool using an inclined surface formed
on the outer end wall.
25. The method of claim 23, wherein the cutting step further
comprises cutting inwardly through the outer end wall.
26. The method of claim 23, wherein the cutting step further
comprises cutting outwardly through the outer end wall.
27. The method of claim 23, wherein the cutting step further
comprises cutting through a check valve.
28. The method of claim 27, further comprising the step of
cementing the first tubular string in the well by flowing cement
outwardly through the check valve prior to the cutting step.
29. The method of claim 23, further comprising the step of guiding
a cutting tool toward the outer end wall using at least one
radioactive source attached to the first tubular string.
30. The method of claim 29, wherein the cutting tool guiding step
further comprises detecting a spaced apart series of the
radioactive sources.
31. The method of claim 29, wherein in the cutting step the first
tubular string is positioned in a first wellbore, and wherein the
cutting tool guiding step further comprises guiding the cutting
tool through a second wellbore.
32. The method of claim 11, wherein the positioning step further
comprises positioning the first tubular string in a first wellbore,
and wherein the guiding step further comprises displacing the
second tubular string in a second wellbore intersecting the first
wellbore.
33. The method of claim 32, further comprising the step of guiding
a cutting tool to form the second wellbore so that it intersects
the first wellbore.
34. The method of claim 33, wherein the cutting tool guiding step
further comprises guiding the cutting tool toward at least one
radioactive source on the first tubular string.
35. The method of claim 33, wherein the cutting tool guiding step
further comprises guiding the cutting tool toward a spaced apart
array of radioactive sources on the first tubular string.
36. The method of claim 11, wherein the guiding step further
comprises displacing the second tubular string through a
window.
37. The method of claim 36, further comprising the step of forming
the window in a sidewall of a third tubular string lining the
second wellbore.
38. The method of claim 11, wherein the expanding step further
comprises applying a pressure differential across a wall of the
entry guide.
39. The method of claim 11, wherein the expanding step further
comprises inflating a membrane within the entry guide.
40. The method of claim 39, further comprising the step of
conveying the membrane into the entry guide on a third tubular
string, and wherein the inflating step further comprises applying
pressure to an interior of the third tubular string.
41. The method of claim 11, further comprising the step of
sealingly engaging the first and second tubular strings with each
other.
42. The method of claim 41, wherein the sealingly engaging step
further comprises attaching a seal on the first tubular string.
43. The method of claim 41, wherein the sealingly engaging step
further comprises attaching a seal on the second tubular
string.
44. The method of claim 41, wherein the sealingly engaging step
further comprises expanding the second tubular string within the
first tubular string.
45. The method of claim 41, wherein the sealingly engaging step
further comprises positioning a seal between the first and second
tubular strings after the guiding step.
46. The method of claim 41, wherein the sealingly engaging step
further comprises swelling a sealing element between the first and
second tubular strings.
47. The method of claim 41, wherein the sealingly engaging step
further comprises causing metal to metal contact between the first
and second tubular strings.
48. The method of claim 11, wherein the guiding step further
comprises inserting a portion of the second tubular string into a
portion of the first tubular string.
49. The method of claim 48, further comprising the step of
expanding the second tubular string portion within the first
tubular string portion.
50. The method of claim 49, wherein the second tubular string
portion expanding step further comprises increasing an inner
dimension of the second tubular string, thereby causing the second
tubular string inner dimension to become equivalent to an inner
dimension of the first tubular string.
51. The method of claim 49, wherein the second tubular string
portion expanding step further comprises increasing an inner
dimension of the second tubular string, thereby causing the second
tubular string inner dimension to become at least as large as an
inner dimension of the first tubular string.
52. The method of claim 49, wherein the second tubular string
portion expanding step further comprises sealingly engaging the
second tubular string portion with the first tubular string
portion.
53. The method of claim 48, wherein in the inserting step, the
first tubular string portion is the entry guide.
54. A well interconnection system, comprising: first and second
wellheads interconnected to each other by first and second tubular
strings in sealed communication with each other at a first
subterranean tubular string connection; a first wellbore junction
disposed between the first wellhead and the first tubular string
connection; and a second wellbore junction disposed between the
second wellhead and the first tubular string connection.
55. The system of claim 54, wherein the first tubular string
includes a screen.
56. The system of claim 55, wherein the screen is gravel
packed.
57. The system of claim 55, wherein the screen is expanded in the
well.
58. The system of claim 55, wherein the screen is positioned
between the first wellbore junction and the first tubular string
connection.
59. The system of claim 54, wherein the first and second wellbore
junctions are interconnected to each other by third and fourth
tubular strings in sealed communication with each other at a second
subterranean tubular string connection.
60. The system of claim 59, wherein the third tubular string
includes a screen.
61. The system of claim 60, wherein the screen is gravel
packed.
62. The system of claim 60, wherein the screen is expanded in the
well.
63. The system of claim 60, wherein the screen is positioned
between the first wellbore junction and the second tubular string
connection.
64. A method of connecting first and second tubular strings in a
well, the method comprising the steps of: providing an expandable
entry guide on the first tubular string; positioning the first
tubular string in a first wellbore; positioning the second tubular
string in a second wellbore intersecting the first wellbore; and
guiding the second tubular string into the first tubular string via
the entry guide.
65. The method of claim 64, wherein the providing step further
comprises providing an inclined surface on the entry guide, and
wherein the guiding step further comprises using the inclined
surface to guide the second tubular string into the first tubular
string.
66. The method of claim 64, wherein the guiding step further
comprises releasing a protective sheath to thereby uncover a seal
on the second tubular string.
67. The method of claim 66, further comprising the step of
sealingly engaging the seal within the first tubular string,
thereby providing sealed communication between the first and second
tubular strings.
68. The method of claim 66, wherein the releasing step further
comprises releasing the sheath from a latch carried on the second
tubular string.
69. The method of claim 68, further comprising the step of engaging
the latch with a profile in the first tubular string, thereby
securing the second tubular string to the first tubular string.
70. The method of claim 64, further comprising the step of securing
the second tubular string to the first tubular string.
71. The method of claim 70, wherein the securing step further
comprises engaging a profile formed within the first tubular
string.
72. The method of claim 71, wherein in the profile engaging step,
the profile is formed within the entry guide.
73. The method of claim 70, wherein the securing step further
comprises expanding the second tubular string within the first
tubular string.
74. The method of claim 70, wherein the securing step further
comprises engaging a latch on the second tubular string with the
first tubular string.
75. The method of claim 70, wherein the securing step further
comprises engaging a latch with a profile.
76. The method of claim 64, further comprising the step of cutting
through an outer end wall of the entry guide.
77. The method of claim 76, wherein the cutting step further
comprises guiding a cutting tool using an inclined surface formed
on the outer end wall.
78. The method of claim 76, wherein the cutting step further
comprises cutting inwardly through the outer end wall.
79. The method of claim 76, wherein the cutting step further
comprises cutting outwardly through the outer end wall.
80. The method of claim 76, wherein the cutting step further
comprises cutting through a check valve.
81. The method of claim 80, further comprising the step of
cementing the first tubular string in the well by flowing cement
outwardly through the check valve prior to the cutting step.
82. The method of claim 76, further comprising the step of guiding
a cutting tool toward the outer end wall using at least one
radioactive source attached to the first tubular string.
83. The method of claim 82, wherein the cutting tool guiding step
further comprises detecting a spaced apart series of the
radioactive sources.
84. The method of claim 82, wherein the cutting tool guiding step
further comprises guiding the cutting tool through the second
wellbore.
85. The method of claim 64, further comprising the step of guiding
a cutting tool to form the second wellbore so that it intersects
the first wellbore.
86. The method of claim 85, wherein the cutting tool guiding step
further comprises guiding the cutting tool toward at least one
radioactive source on the first tubular string.
87. The method of claim 85, wherein the cutting tool guiding step
further comprises guiding the cutting tool toward a spaced apart
array of radioactive sources on the first tubular string.
88. The method of claim 64, wherein the guiding step further
comprises displacing the second tubular string through a
window.
89. The method of claim 88, further comprising the step of forming
the window in a sidewall of a third tubular string lining the
second wellbore.
90. The method of claim 64, further comprising the step of
expanding the entry guide by applying a pressure differential
across a wall of the entry guide.
91. The method of claim 64, further comprising the step of
expanding the entry guide by inflating a membrane within the entry
guide.
92. The method of claim 91, further comprising the step of
conveying the membrane into the entry guide on a third tubular
string, and wherein the inflating step further comprises applying
pressure to an interior of the third tubular string.
93. The method of claim 64, further comprising the step of
sealingly engaging the first and second tubular strings with each
other.
94. The method of claim 93, wherein the sealingly engaging step
further comprises attaching a seal on the first tubular string.
95. The method of claim 93, wherein the sealingly engaging step
further comprises attaching a seal on the second tubular
string.
96. The method of claim 93, wherein the sealingly engaging step
further comprises expanding the second tubular string within the
first tubular string.
97. The method of claim 93, wherein the sealingly engaging step
further comprises positioning a seal between the first and second
tubular strings after the guiding step.
98. The method of claim 93, wherein the sealingly engaging step
further comprises swelling a sealing element between the first and
second tubular strings.
99. The method of claim 93, wherein the sealingly engaging step
further comprises causing metal to metal contact between the first
and second tubular strings.
100. The method of claim 64, wherein the guiding step further
comprises inserting a portion of the second tubular string into a
portion of the first tubular string.
101. The method of claim 100, further comprising the step of
expanding the second tubular string portion within the first
tubular string portion.
102. The method of claim 101, wherein the second tubular string
portion expanding step further comprises increasing an inner
dimension of the second tubular string, thereby causing the second
tubular string inner dimension to become equivalent to an inner
dimension of the first tubular string.
103. The method of claim 101, wherein the second tubular string
portion expanding step further comprises increasing an inner
dimension of the second tubular string, thereby causing the second
tubular string inner dimension to become at least as large as an
inner dimension of the first tubular string.
104. The method of claim 101, wherein the second tubular string
portion expanding step further comprises sealingly engaging the
second tubular string portion with the first tubular string
portion.
105. The method of claim 100, wherein in the inserting step, the
first tubular string portion is the entry guide.
106. A well interconnection system, comprising: first, second and
third wellheads interconnected to each other substantially
underground.
107. The system of claim 106, wherein the first and second
wellheads are interconnected to each other by first and second
tubular strings in sealed communication with each other at a first
subterranean tubular string connection.
108. The system of claim 107, wherein the second and third
wellheads are interconnected to each other by third and fourth
tubular strings in sealed communication with each other at a second
subterranean tubular string connection.
109. The system of claim 106, wherein the second wellhead comprises
a pumping station for transferring fluid between the first and
third wellheads.
110. The system of claim 106, wherein the first and second
wellheads are interconnected via first and second intersecting
wellbores.
111. The system of claim 110, wherein the second and third
wellheads are interconnected via third and fourth intersecting
wellbores.
Description
BACKGROUND
[0001] The present invention relates generally to equipment
utilized and operations performed in conjunction with a
subterranean well and, in an embodiment described herein, more
particularly provides a tubular string connection for U-tube
wells.
[0002] It is known to drill a wellbore so that it intersects
another wellbore. Examples of intersecting wellbores include U-tube
wells and multilateral or branching wells. It is also known to
interconnect tubular strings, such as casing, liner or tubing
strings, in the intersecting wellbores.
[0003] However, prior systems for interconnecting tubular strings
in intersecting wellbores have suffered from some disadvantages.
For example, in these systems one tubular string is typically
inserted into an interior of another tubular string. This generally
requires that the inserted string have a reduced inner diameter,
which restricts flow and access through the string. Another
disadvantage is that it is at times difficult to align the tubular
strings so that they properly engage each other.
[0004] Therefore, it may be seen that it would be beneficial to
provide improved systems and methods for interconnecting tubular
strings in intersecting wellbores. These systems and methods could
be useful in other applications, as well.
SUMMARY
[0005] In carrying out the principles of the present invention, in
accordance with an embodiment thereof, a tubular string connection
system is provided which may be used to interconnect tubular
strings in U-tube wells. Associated methods are also provided.
[0006] In one aspect of the invention, a tubular string connection
system is provided which includes a first tubular string having an
expanded entry guide. A second tubular string has an end guided
into the first tubular string by the entry guide.
[0007] In another aspect of the invention, a method of connecting
first and second tubular strings in a well is provided. The method
includes the steps of: providing an expandable entry guide on the
first tubular string; positioning the entry guide in the well, and
then expanding the entry guide; and guiding the second tubular
string into the first tubular string.
[0008] In yet another aspect of the invention, a well
interconnection system is provided. The system includes two
wellheads interconnected to each other by two tubular strings in
sealed communication with each other at a subterranean tubular
string connection. A wellbore junction is positioned between one of
the wellheads and the tubular string connection. Another wellbore
junction is positioned between the other wellhead and the tubular
string connection.
[0009] In a further aspect of the invention, a method of connecting
tubular strings in a well includes the steps of: providing an
expandable entry guide on one of the tubular strings; positioning
the tubular string in a wellbore; positioning another tubular
string in another wellbore intersecting the first wellbore; and
guiding the second tubular string into the first tubular string via
the entry guide.
[0010] In a still further aspect of the invention, a well
interconnection system is provided. The system includes first,
second and third wellheads interconnected to each other
substantially underground. The second, or middle, wellhead may
operate as a pumping station for transferring fluid between the
first and third wellheads.
[0011] These and other features, advantages, benefits and objects
of the present invention will become apparent to one of ordinary
skill in the art upon careful consideration of the detailed
description of representative embodiments of the invention
hereinbelow and the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] FIG. 1 is a schematic partially cross-sectional view of a
tubular string connection system and method embodying principles of
the present invention;
[0013] FIG. 2 is a schematic partially cross-sectional view of the
system and method of FIG. 1, in which additional steps of the
method have been performed;
[0014] FIG. 3 is a schematic partially cross-sectional view of the
system and method, in which still further steps of the method have
been performed;
[0015] FIG. 4 is a schematic partially cross-sectional view of
optional configuration and steps in the system and method;
[0016] FIG. 5 is a schematic partially cross-sectional view of
further optional configuration and steps in the system and
method;
[0017] FIG. 6 is a schematic partially cross-sectional view of
still further optional configuration and steps in the system and
method;
[0018] FIG. 7 is a schematic partially cross-sectional view of
additional optional configuration and steps in the system and
method;
[0019] FIG. 8 is a schematic partially cross-sectional view of
another tubular string connection system and method embodying
principles of the present invention;
[0020] FIG. 9 is a schematic partially cross-sectional view of a
system and method for expanding an entry guide in the system and
method of FIGS. 1 & 8;
[0021] FIG. 10 is a schematic view of a well interconnection system
and method embodying principles of the present invention;
[0022] FIGS. 11A & B are schematic cross-sectional views of
another tubular string connection system and method embodying
principles of the present invention; and
[0023] FIG. 12 is a schematic view of another well interconnection
system and method embodying principles of the present
invention.
DETAILED DESCRIPTION
[0024] Representatively illustrated in FIG. 1 is a tubular string
connection system 10 and associated method which embody principles
of the present invention. In the following description of the
system 10 and other apparatus and methods described herein,
directional terms, such as "above", "below", "upper", "lower",
etc., are used for convenience in referring to the accompanying
drawings. Additionally, it is to be understood that the various
embodiments of the present invention described herein may be
utilized in various orientations, such as inclined, inverted,
horizontal, vertical, etc., and in various configurations, without
departing from the principles of the present invention.
[0025] As depicted in FIG. 1, a wellbore 12 has been drilled and a
radially enlarged underreamed cavity 14 has been formed at a lower
end of the wellbore. Note that it is not necessary for a cavity to
be formed, or for the cavity to be positioned as shown in FIG. 1.
For example, the cavity 14 could be formed in the wellbore 12
uphole from the lower end. Thus, it should be clearly understood
that the invention is not limited to the specific details of the
described embodiments.
[0026] A tubular string 16 is conveyed into the wellbore 12. The
tubular string 16 could be a casing, liner, tubing, or other type
of tubular string. At its lower end, the tubular string 16 includes
an expandable entry guide 18 in an unexpanded configuration. The
entry guide 18 is positioned within the cavity 14.
[0027] Referring additionally now to FIG. 2, the entry guide 18 is
depicted in cross-section in its expanded configuration. The entry
guide 18 is preferably expanded by applying increased pressure to
the interior of the tubular string 16, thereby inflating the entry
guide by applying a pressure differential across walls 20, 22 of
the entry guide.
[0028] Other expanding means could be used, if desired. For
example, the entry guide 18 could be mechanically swaged or drifted
to force its walls 20, 22 outward. In that case, the walls 20, 22
would not need to be pressure-bearing. Another expansion method is
described below in relation to FIG. 9.
[0029] In the cross-sectional view depicted in FIG. 2, it may be
seen that the tubular string 16 also includes a latching profile 24
and a seal bore 26. These are shown in the tubular string 16 uphole
from the entry guide 18, but they could be otherwise positioned.
For example, the profile 24 and bore 26 could be formed on an inner
side surface of the wall 20 of the entry guide 18, if desired.
[0030] The tubular string 16 is cemented in the wellbore 12 after
expanding the entry guide 18. For this purpose, a check valve or
cementing shoe 28 is provided in the outer end wall 22 of the entry
guide 18. Cement 30 is flowed downwardly through the tubular string
16, and then outwardly through the check valve 28 into the wellbore
12, where it is permitted to harden.
[0031] Note that the terms "cement" and "cementing" are used herein
to indicate not only the use of cementitious material, but also the
use of any other hardenable material, such as epoxies, plastics,
foams, etc., which may be used in an annulus between a tubular
string and a wellbore to secure and/or seal the tubular string in
the wellbore. In addition, it should be understood that it is not
necessary for the tubular string 16 to be cemented in the wellbore
12 at all. The wellbore 12 could be left wholly or partially open
hole, if desired.
[0032] It may be seen that the outer end wall 22 of the entry guide
18 presents an inclined generally conical exterior surface 32.
Similarly, the side wall 20 presents an inclined generally conical
interior surface 34. As described more fully below, the inclined
surface 32 may be used to guide a cutting tool to cut through a
center of the wall 22, and the inclined surface 34 may be used to
guide another tubular string toward the seal bore 26 and latching
profile 24 in the interior of the tubular string 16.
[0033] Referring additionally now to FIG. 3, the system 10 is
depicted after another wellbore 36 has been drilled to intersect
the wellbore 12. In this embodiment, a lower end of the wellbore 36
intersects a lower end of the wellbore 12, so that the wellbores
are inline with each other at their intersection, thereby forming a
U-tube well. However, the wellbores 12, 36 could intersect in other
configurations, if desired.
[0034] As the wellbore 36 is being drilled to intersect the
wellbore 12, a cutting tool, such as a drill bit, will eventually
contact the inclined surface 32. Such contact between the cutting
tool and the surface 32 will operate to guide the cutting tool
toward the center of the wall 22, thereby helping to align the
wellbore 36 with the other wellbore 16 and the entry guide 18
therein. As depicted in FIG. 3, the cutting tool has cut through
the center of the wall 22, thereby cutting through the cementing
shoe 28.
[0035] After the wellbore 36 has been drilled, another tubular
string 38 is conveyed into the wellbore. At its lower end, the
tubular string 38 includes a latch 40 and a seal 42. The lower end
of the tubular string 38 enters the entry guide 18 from the
wellbore 36 and the inclined surface 34 guides the tubular string
so that it is inserted into the other tubular string 16.
[0036] The latch 40 engages the profile 24 to releasably secure the
tubular strings 16, 38 to each other. The seal 42 sealingly engages
the seal bore 26 to form a sealed connection between the tubular
strings 16, 38. Note that, if the seal bore 26 and profile 24 were
formed on the interior of the wall 20, then the sealed and secured
connection between the strings 16, 38 could be made at an increased
diameter which would not restrict flow or access through the
connection.
[0037] Instead of the seal 42 and latch 40, the tubular string 38
could have any other types of sealing and securing devices. For
example, an expandable sealing and securing device, such as the
VersaFlex.TM. expandable liner hanger available from Enventure
Global Technologies of Houston, Tex. could be used on the tubular
string 38. In that case, the seal bore 26 and latching profile 24
may not be used in the tubular string 16.
[0038] Referring additionally now to FIG. 4, another embodiment of
a tubular string connection system 44 is representatively
illustrated. Features of the system 44 which are similar to those
previously described are indicated in FIG. 4 using the same
reference numbers. The system 44 differs from the system 10 at
least in part in that the seal 42 is protected by an outer tubular
sheath 46 while the tubular string 38 is conveyed through the
wellbore 36.
[0039] While the tubular string 38 is being conveyed through the
wellbore 36, the sheath 46 is maintained in position overlying the
seal 42 by engagement between the latch 40 and a latching profile
48 formed within the sheath. As the lower end of the tubular string
38 enters an expanded entry guide 50, the sheath 46 eventually
contacts the inclined portion of the wall 20, thereby releasing the
latch 40 from the profile 48. The lower end of the tubular string
38 is then permitted to enter the tubular string 16, where the
uncovered seal 42 seals against the bore 26 and the latch 40
engages the profile 24.
[0040] Note that in this embodiment the entry guide 50 is not
cemented in the wellbore 12 and the entry guide does not have the
outer end wall 22. The tubular strings 16, 38 could be conveyed
into the wellbores 12, 36 after both of the wellbores have been
drilled. The entry guide 50 could have been mechanically
expanded.
[0041] Referring additionally now to FIG. 5, the system 10 is
depicted while the wellbore 36 is being drilled. A series of spaced
apart radioactive sources 52 are attached to the tubular string 16
in an inline array. A drill string 54 used to drill the wellbore 36
includes a cutting tool or drill bit 56 and a detector 58.
[0042] The detector 58 detects the radiation given off by the
sources 52. For example, the sources 52 may emit gamma rays and the
detector 58 may include a gamma ray sensor. Based on the
characteristics of the detected radiation, the drill string 54 is
guided toward the radioactive sources 52 and, thus, to intersect
the wellbore 12.
[0043] Note that it is not necessary for there to be multiple
sources 52. A single source 52 could provide a target for guiding
the cutting tool 56, for example, based on the strength of the
detected radiation. However, it is believed that the spaced apart
array of sources 52 will provide additional characteristics (such
as spatial distribution, etc.) to the radiation emitted by the
sources so that increased accuracy in guiding the cutting tool 56
is obtained.
[0044] In FIG. 5, the cavity 14 is depicted formed in the wellbore
12 spaced apart from a lower portion 60 of the wellbore. As the
cutting tool 56 cuts into the lower wellbore portion 60, thereby
forming the intersection between the wellbores 12, 36, this lower
wellbore portion will aid in aligning the cutting tool 56 so that
it is inline with the wellbore 12. That is, it will be easier for
the cutting tool 56 to proceed inline with the lower wellbore
portion 60 than to deviate therefrom. In this case, the wellbore 12
may be left uncemented (at least, until the tubular strings 16, 38
are connected) to enhance this effect of the lower wellbore portion
60.
[0045] Referring additionally now to FIG. 6, another tubular string
connection system 62 is representatively illustrated. Features of
the system 62 which are similar to those previously described are
indicated in FIG. 6 using the same reference numbers. The system 62
differs from the systems 10, 44 at least in part in that the outer
end wall 22 of an expanded entry guide 64 is cut through from the
inside out, that is, in an outward direction.
[0046] In this embodiment, a drill string 65, such as a coiled
tubing string, is conveyed through the tubular string 16 after the
entry guide 64 is expanded. The drill string 65 includes a cutting
tool 66, such as a tapered mill, for cutting through the end wall
22. To help guide the cutting tool 66 toward the center of the wall
22, an interior surface 68 of the wall may be inclined, such as the
generally conical shape depicted in FIG. 6. However, the end wall
22 may still have the exterior inclined surface 32 formed on it,
for example, to guide the tubular string 38 into the entry guide 64
after the wall is cut through.
[0047] The drill string 65 could also include an underreamer 70 if,
for example, it is desired to cut most, or all, of the end wall 22
away to provide a larger opening for the tubular string 38 to
enter. In FIG. 7, the system 62 is depicted with an alternately
configured entry guide 64, in which the inclined surface 32 is not
provided on the end wall 22. Instead, the underreamer 70 is used to
cut away substantially all of the end wall 22, and so the inclined
surface 32 is not used.
[0048] Referring additionally now to FIG. 8, another tubular string
connection system 72 is representatively illustrated. This system
72 is useful in situations where it is desired to form a connection
between tubular strings 74, 76 in intersecting wellbores 78, 80. In
the situation depicted in FIG. 8, the wellbore 78 has been washed
out near the intersection between the wellbores 78, 80, and so it
would be difficult to properly align the tubular strings 74, 76
using conventional methods.
[0049] In the system 72, the tubular string 74 includes an
expandable entry guide 82 at its upper end. The entry guide 82 is
positioned in the washed out section 84 of the wellbore 78, and is
then expanded outward to the configuration shown in FIG. 8. Note
that the entry guide 82 could be of use in other enlarged wellbore
sections, whether or not they are washed out, such as intentionally
enlarged wellbore sections (e.g., underreamed wellbores), etc.
[0050] The tubular string 76 is conveyed through the wellbore 80
and is deflected by a deflector 88 outwardly through a window 86.
The window 86 was previously formed through a casing string 89
lining the wellbore 80 when the wellbore 78 was drilled outwardly
from the wellbore 80. However, the window 86 could be formed,
and/or the casing string 89 could be installed after the wellbore
78 is drilled, if desired. Furthermore, it is not necessary for the
wellbore 80 to be lined with the casing 89 at all.
[0051] The tubular string 76 is deflected into the wellbore 78 and
is lowered until it enters the entry guide 82. The seal 42 and
latch 40 engage the seal bore 26 and profile 24 in the tubular
string 74 as described above for the system 10. Note that the seal
42 may be protected by the sheath 46 while being conveyed through
the wellbores 78, 8o, as described above for the system 44. The
sheath 46 would then be released when the tubular string 76 engages
the entry guide 82, to uncover the seal 42 and permit it to seal
against the bore 26. Alternatively, other sealing and/or securing
devices, such as an expandable liner hanger, could be used in place
of the seal 42 and/or latch 40.
[0052] Referring additionally now to FIG. 9, another method of
expanding the entry guide 82 in the system 72 is representatively
illustrated, apart from the remainder of the system shown in FIG.
8. In this method, a tubular string 90 is received in the entry
guide 82. The tubular string 90 may be used to convey the tubular
string 74 into the wellbore 78.
[0053] Thus, the tubular string 90 could include a latch (such as
the latch 40) releasably attached to the profile 24 in the tubular
string 74 while the tubular string 74 is being conveyed through the
wellbore 80 and into the wellbore 78. Alternatively, the tubular
string 90 could be inserted into the end of the tubular string 74
after the tubular string 74 is conveyed into the wellbore 78.
[0054] As another alternative, the tubular string 90 could be
conveyed through the tubular string 74 in the branch or lateral
wellbore 78 and into the entry guide 82. In the system 10
illustrated in FIG. 1, the tubular string 90 could be conveyed
through the tubular string 16 in the main or parent wellbore 12 and
into the entry guide 18 to expand the entry guide. Thus, the
tubular string 90 can be conveyed into an expandable entry guide
from any direction and in any type of wellbore in keeping with the
principles of the invention.
[0055] The tubular string 90 includes an inflatable bladder or
membrane 92. An interior of the membrane 92 is in communication
with an interior of the tubular string 90 via openings 94 formed
through a sidewall of the string. When it is desired to expand the
entry guide 82, pressure is applied to the interior of the tubular
string 90 to inflate the membrane 92. This applies an outwardly
directed force to the interior surfaces of the entry guide 82,
thereby causing it to deform outwardly and expand.
[0056] The entry guide 82 is depicted in FIG. 9 in its expanded
configuration with the membrane 92 inflated therein. Note that a
restraining device 96 carried on the tubular string 90 operates to
restrain the open end of the entry guide 82 to a circular or
cylindrical configuration. The device 96 also maintains the
membrane 92 within the entry guide 82 when the membrane is
inflated. The device 96 could be collapsed or retracted inwardly,
if desired, when the tubular string 90 is retrieved after expanding
the entry guide 82.
[0057] Referring additionally now to FIG. 10, a well
interconnection system 100 is representatively illustrated from a
top view thereof. The system 100 is used to interconnect two
wellheads 102, 104. The wellheads 102, 104 are interconnected using
principles of the invention described above.
[0058] A wellbore 106 drilled from the wellhead 102 intersects a
wellbore 108 drilled from the wellhead 104. These wellbores 106,
108 may form a U-tube well. A tubular string 110 in the wellbore
106 may be connected to a tubular string 112 in the wellbore 108
using a tubular string connection system 10 as described above. Any
of the other tubular string connection systems 44, 62, 72 described
above could be used in place of the system 10.
[0059] A branch wellbore 114 drilled outwardly from the wellbore
106 intersects another branch wellbore 116 drilled outwardly from
the wellbore 108. Yet another branch wellbore 118 drilled outwardly
from the wellbore 106 intersects another branch wellbore 120
drilled outwardly from the wellbore 108.
[0060] A tubular string 122 in the wellbore 114 is connected to a
tubular string 124 in the wellbore 116 using the tubular string
connection system 10 (or another of the systems described above).
Similarly, a tubular string 126 in the wellbore 118 is connected to
a tubular string 128 in the wellbore 120.
[0061] A wellbore junction 130 interconnects the tubular strings
11o, 126. A wellbore junction 132 interconnects the tubular strings
110, 122. A wellbore junction 134 interconnects the tubular strings
112, 128. A wellbore junction 136 interconnects the tubular strings
112, 124.
[0062] These wellbore junctions 130, 132, 134, 136 may be of the
type described in U.S. patent application Ser. No. 10/725,140,
filed Dec. 1, 2003, the entire disclosure of which is incorporated
herein by this reference. Such wellbore junctions will permit
independent control and monitoring of fluid flow between each of
the branch wellbores 114, 116, 118, 120 and the respective
wellbores 106, 108.
[0063] It may now be appreciated that the principles of the
invention permit a wide variety of tubular string connection
configurations in the system 100, thereby permitting a petroleum
reservoir to be drained as desired using wellbores intersecting
each other in various ways.
[0064] Note that any of the tubular strings 110, 112, 122, 124,
126, 128 can be gravel packed at any point in any of the respective
wellbores 106, 108, 114, 116, 118, 120. For example, FIG. 10
depicts the tubular string 110 gravel packed about a screen 138
positioned between the tubular string connection 10 and the
wellbore junction 132, the tubular string 112 gravel packed about a
screen 140 positioned between the tubular string connection 10 and
the wellbore junction 134, and the tubular string 126 gravel packed
about a screen 142 positioned between the wellbore junction 130 and
the tubular string connection 1o.
[0065] The screens 138, 140, 142, or any of them, could be
expandable. For example, the PoroFlex.RTM. expandable screen
available from Enventure Global Technologies of Houston, Tex. could
be used. If the screens 138, 140, 142 are used, they may not
necessarily be gravel packed.
[0066] Referring additionally now to FIGS. 11A & B, another
tubular string connection system 150 is representatively
illustrated. The system 150 may be used in U-tube wells (such as
depicted above for the system 10), or in intersecting and branch
wellbores (such as depicted above for the system 72), or in any
other type of well or well system, whether or not the well includes
intersecting wellbores.
[0067] As depicted in FIG. 11A, the system 150 is used to connect
two tubular strings 152, 154. Instead of expanding an entry guide
prior to connecting the tubular strings 152, 154, in the system 150
the tubular string 152 has a reduced diameter portion 156 at an end
thereof, which is inserted into the tubular string 154. A sealing
element 158 is attached externally to the reduced diameter
portion.
[0068] As depicted in FIG. 11B, the reduced diameter portion 156 is
expanded radially outward, so that the sealing element 158
sealingly engages the interior of the tubular string 154. The
sealing element 158 could be an elastomer, a non-elastomer, a
material which swells upon contact with well fluids, a metal, etc.,
or any other type of material. The sealing element 158 could be
carried internally on the tubular string 154, instead of externally
on the tubular string 152. The sealing element 158 could be
installed or positioned between the tubular strings 152, 154 before
or after the tubular strings are engaged with each other. Contact
between the tubular strings 152, 154 (e.g., when the inner tubular
string is expanded) can cause sealing engagement between the
tubular strings, even without use of a distinct sealing
element.
[0069] The tubular string 152 could be expanded mechanically (e.g.,
by swaging, drifting, or other type of mechanical forming),
hydraulically (e.g., by applying pressure across a sidewall of the
tubular string, inflating a membrane, etc.), or by any other
method, or any combination of methods.
[0070] Expansion of the reduced diameter portion 156 expands a
minimum restriction or an inner dimension d of a flow passage 160
of the tubular string 152 as shown in FIG. 11A. After the
expansion, the flow passage 160 preferably has a minimum
restriction or inner dimension substantially equivalent to, or no
less than, a minimum restriction or inner dimension D of the
tubular string 154 (as shown in FIG. 11B). In this manner, the
system 150 does not present a significant restriction to access or
flow of fluids through the passages 160, 162, although some
restriction may be present without departing from the principles of
the invention.
[0071] Note that expansion of the portion 156 of the tubular string
152 also causes expansion of an end portion 164 of the tubular
string 154. However, the end portion 164 could be expanded before
the tubular string 152 is inserted into the tubular string 154, in
which case, the end portion could be considered an entry guide on
the tubular string 154. Note, also, that in any of the
above-described systems 10, 44, 62, 72, 100 a tubular string (e.g.,
tubular strings 38, 76, 124, 112, 128) can be sealingly engaged
within an entry guide (e.g., entry guides 18, 50, 64, 82) on
another tubular string (e.g., tubular strings 16, 74, 122, 110,
126) to thereby reduce or prevent restrictions to access or flow
through the connected tubular strings, whether or not the inserted
tubular string is expanded within the entry guide.
[0072] Referring additionally now to FIG. 12, another well
interconnection system 170 is representatively illustrated from a
side view thereof. The system 170 is used to interconnect three
wellheads 172, 174, 176. The wellheads 172, 174, 176 are
interconnected using principles of the invention described
above.
[0073] A wellbore 178 drilled from the wellhead 172 intersects a
wellbore 180 drilled from the wellhead 174. These wellbores 178,
180 may form a U-tube well. A tubular string 182 in the wellbore
178 may be connected to a tubular string 184 in the wellbore 180
using a tubular string connection system 10 as described above. Any
of the other tubular string connection systems 44, 62, 72, 150
described above could be used in place of the system 10.
[0074] A wellbore 186 drilled from the wellhead 174 intersects a
wellbore 188 drilled from the wellhead 176. These wellbores 186,
188 may form a U-tube well. The wellbore 186 could be a branch of
the wellbore 180, or vice versa. A tubular string 190 in the
wellbore 186 may be connected to a tubular string 192 in the
wellbore 188 using a tubular string connection system 10, or any of
the other connection systems 44, 62, 72, 150 described above. The
tubular strings 184, 190 may be joined to, or in communication
with, each other at the wellhead 174 or in either of the wellbores
18o, 186 below the wellhead.
[0075] The wellhead 174 may be used as a pumping station to
transfer fluid between the tubular strings 184, 190. In this
manner, fluid may be pumped substantially underground from wellhead
172 to wellhead 176. Any number of wellheads may be joined using
this method to transfer fluid substantial distances underground.
This may be beneficial in that sensitive surface environments may
be avoided, unstable surface conditions or difficult surface
topology may be avoided, the transferred fluid may be maintained at
a desired temperature geothermally, etc.
[0076] Although tubular string connection systems 10, 44, 62, 72,
100, 150, 170 have been described above for use with tubular
strings positioned in intersecting wellbores, the systems could
also be used in a wellbore, or a section of a wellbore, that does
not intersect another wellbore. For example, the intersecting
wellbores 12, 36 in the systems 10, 44, 62 could instead be a
single continuous wellbore. The system 72 could also be used in a
continuous wellbore. In the system 100, each of the intersecting
wellbores 106, 108, intersecting wellbores 114, 116, and
intersecting wellbores 118, 120, or any combination of them, could
be drilled as a continuous wellbore. In the system 170, each of the
intersecting wellbores 178, 180 and intersecting wellbores 186, 188
could be drilled as a continuous wellbore.
[0077] Of course, a person skilled in the art would, upon a careful
consideration of the above description of representative
embodiments of the invention, readily appreciate that many
modifications, additions, substitutions, deletions, and other
changes may be made to these specific embodiments, and such changes
are contemplated by the principles of the present invention.
Accordingly, the foregoing detailed description is to be clearly
understood as being given by way of illustration and example only,
the spirit and scope of the present invention being limited solely
by the appended claims and their equivalents.
* * * * *