U.S. patent application number 09/312140 was filed with the patent office on 2001-12-06 for in-tubing wellbore sidetracking operations.
Invention is credited to BINGHAM, BRIAN, DAWSON, ALEX, DUGUID, DAVID, HAUGEN, DAVID M., HORST, TODD, LONGBOTTOM, JAMES, MIDDLETON, FRANK ALEXANDER, ROBERTS, JOHN D..
Application Number | 20010047872 09/312140 |
Document ID | / |
Family ID | 23210056 |
Filed Date | 2001-12-06 |
United States Patent
Application |
20010047872 |
Kind Code |
A1 |
ROBERTS, JOHN D. ; et
al. |
December 6, 2001 |
IN-TUBING WELLBORE SIDETRACKING OPERATIONS
Abstract
Methods are disclosed for wellbore operations in an earth
wellbore with tubing within casing in an earth wellbore, the
wellbore extending down into earth from an earth surface, the
tubing including a tubing string with a lower end and extending
down within the casing with the lower end at a point above a lower
end of the casing, a tubing-casing annulus between the tubing and
the casing sealed by a first sealing apparatus, the method
including sealing the lower end of the tubing string with a sealing
device to prevent fluid flow therethrough, and sealing the tubing
casing annulus with a second sealing apparatus above and spaced
apart from the first sealing apparatus. In certain aspects the
sealing apparatuses provide upper and lower spaced-apart primary
barriers. The methods in additional aspects include making an exit
opening through the tubing and an exit opening through the casing,
each exit opening located between the first sealing apparatus and
the second sealing apparatus. In other aspects the methods include
drilling a lateral wellbore from the exit opening through the
casing. Apparatus is disclosed that is useful in such methods.
Inventors: |
ROBERTS, JOHN D.; (SPRING,
TX) ; LONGBOTTOM, JAMES; (MAGNOLIA, TX) ;
HAUGEN, DAVID M.; (LEAGUE CITY, TX) ; DAWSON,
ALEX; (KEITH, GB) ; DUGUID, DAVID; (ABERDEEN,
GB) ; MIDDLETON, FRANK ALEXANDER; (DUBAI, SA)
; BINGHAM, BRIAN; (PEARLEND, TX) ; HORST,
TODD; (HOUSTON, TX) |
Correspondence
Address: |
GUY MCCLUNG
PMB 347
16690 CHAMPION FOREST DRIVE
SPRING
TX
77379-7023
US
|
Family ID: |
23210056 |
Appl. No.: |
09/312140 |
Filed: |
May 14, 1999 |
Current U.S.
Class: |
166/387 ;
166/191; 166/241.1; 166/50 |
Current CPC
Class: |
E21B 29/005 20130101;
E21B 29/02 20130101; E21B 43/305 20130101; E21B 7/061 20130101 |
Class at
Publication: |
166/387 ;
166/241.1; 166/191; 166/50 |
International
Class: |
E21B 023/00; E21B
017/10 |
Claims
What is claimed is:
1. A method for wellbore operations in an earth wellbore with
tubing within casing in an earth wellbore, the wellbore extending
down into earth from an earth surface, the tubing comprising a
tubing string with a lower end and extending down within the casing
with the lower end at a point above a lower end of the casing, a
tubing-casing annulus between the tubing and the casing sealed by a
first sealing apparatus, the method comprising sealing the lower
end of the tubing string with a sealing device to prevent fluid
flow therethrough, and sealing the tubing-casing annulus with a
second sealing apparatus above and spaced apart from the first
sealing apparatus.
2. The method of claim 1 further comprising making an exit opening
through the tubing and an exit opening through the casing, each
exit opening located above the first sealing apparatus.
3. The method of claim 1 further comprising stabilizing the tubing
at a location above the first sealing apparatus.
4. The method of claim 1 further comprising perforating the tubing
string at a level above a level of the first sealing apparatus
producing at least one perforation, introducing a hardenable
material into the tubing-casing annulus through the at least one
perforation and flowing the hardenable material within said annulus
up to a level spaced-apart from and above the level of the first
sealing apparatus.
5. The method of claim 4 further comprising hardening the
hardenable material.
6. The method of claim 4 wherein the hardenable material is
cement.
7. The method of claim 4 wherein the at least one perforation is a
plurality of perforations.
8. The method of claim 1 wherein the wellbore includes a first
completion zone located below the lower end of the tubing.
9. The method of claim 1 wherein the second sealing apparatus is a
primary barrier.
10. The method of claim 1 wherein the first sealing device and the
second sealing apparatus constitute a primary barrier.
11. The method of claim 1 wherein, prior to sealing the
tubing-casing annulus with the second sealing apparatus, the method
includes removing a section of the tubing above the first sealing
apparatus, moving the second sealing apparatus down through the
tubing to the area from which the section of tubing has been
removed, and activating the second sealing apparatus to seal off
the tubing-casing annulus.
12. The method of claim 2 wherein the exit openings are made with a
mill.
13. The method of claim 12 wherein the mill is on a tubular string
extending from the earth surface and the mill is rotated for
milling by the tubular string.
14. The method of claim 13 wherein the mill is moved downwardly by
moving the tubular string downwardly.
15. The method of claim 13 wherein the mill is moved upwardly by
moving the tubular string upwardly.
16. The method of claim 12 wherein the mill is connected to a
downhole motor on a tubular string in the wellbore and the downhole
motor rotates the mill for milling.
17. The method of claim 16 wherein the mill is moved downwardly by
moving the tubular string downwardly.
18. The method of claim 16 wherein the mill is moved upwardly by
moving the tubular string upwardly.
19. The method of claim 16 wherein the downhole motor is
interconnected with movement apparatus that is anchorable in the
tubing at a point below the earth surface, the movement apparatus
for moving the downhole motor and mill downwardly during
milling.
20. The method of claim 16 wherein the downhole motor is
interconnected with movement apparatus anchorable in the tubing at
a point below the earth surface, the movement apparatus for moving
the downhole motor and the mill upwardly during milling.
21. The method of claim 11 wherein the section of tubing is made by
explosive means for severing the tubing at two spaced-apart
locations.
22. The method of claim 21 wherein the explosive means is on a
movable tubular string on the wellbore and includes a securement
apparatus securable within the tubing at the location of the
section of tubing to be removed, the securement apparatus remaining
secured with the section of tubing following severing of the tubing
by the explosive means, the method further comprising lowering the
section of tubing to expose a gap in the tubing into which the
second sealing apparatus may be moved.
23. The method of claim 1 further comprising making a tubing
opening in the tubing above the first sealing apparatus, installing
a centralizer for centralizing the tubing within the casing, the
centralizer having a hollow body through which hardenable material
is pumpable out through the centralizer, through the tubing
opening, and into the tubing-casing annulus.
24. The method of claim 2 further comprising installing a whipstock
within the tubing for directing a mill for making the exit
openings.
25. The method of claim 24 further comprising removing the
whipstock after the exit openings are made.
26. The method of claim 2 further comprising drilling a lateral
wellbore from the exit opening through the casing.
27. The method of claim 26 further comprising installing a liner in
at least a portion of the lateral wellbore.
28. Any patentable invention disclosed herein.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention is directed to wellbore operations,
in-tubing sidetracking operations, wellbore milling procedures, and
apparatuses and systems useful in such operations and
procedures.
[0003] 2. Description of Related Art
[0004] Many completed wells have one or more strings of tubing
extending within casing from the surface (or from a tubing hanger)
down within the well to a location above completion apparatus in a
completion zone. Typically the interface at the lower end of the
tubing string and the interior of well casing is sealed, e.g. with
a packer or other sealing device. It is also common for a travel
joint between the packer and tubing end to accommodate relative
movement between the two.
[0005] Often it is desirable to produce the well from alternate
zones, including, but not limited to, a location above the packer
at the end of the tubing string. In several prior art methods, the
tubing string is removed to accomplish a sidetracking operation
above the level of the original completion zone. Once the tubing is
removed a new annulus or primary barrier is installed above a new
tubing-casing exit from which a new lateral wellbore extends.
[0006] In various prior art methods, new exits (exit openings
through tubing, cement and casing) have been provided, an new
lateral wellbores drilled therefrom, with the exits positioned
below an existing annulus barrier. Such exits and lateral wellbores
have been established using coiled tubing without requiring the use
of a rig above the wellbore.
[0007] Often it is desirable to move up above a current completion
zone due to, e.g., offset distance of a new drainage target which
requires a well path beginning at a higher point in the wellbore
due to maximum build angles versus the distance a well can be
drilled due to friction of pipes pushed around curves in the
wellbore.
[0008] There has long been a need for an efficient and effective
method for re-completing a well in tubing above a previous
completion location. There has long been a need for such a method
that efficiently and effectively provides a suitable opening or
window through tubing and casing for drilling a sidetracked lateral
wellbore at a desired re-completion location. There has long been a
need, recognized by the present inventors, for stabilizing tubing
at the desired re-completion location. There has long been a need
for such a system and method wherein a new primary barrier is
provided without the need to remove an entire tubing string.
SUMMARY OF THE PRESENT INVENTION
[0009] The present invention, in certain aspects, provides a method
for wellbore operations in an earth wellbore with tubing within
casing in an earth wellbore, the wellbore extending down into earth
from an earth surface, the tubing comprising a tubing string with a
lower end and extending down within the casing with the lower end
at a point above a lower end of the casing, a tubing-casing annulus
between the tubing and the casing sealed by a first sealing
apparatus, the method including sealing the lower end of the tubing
string with a sealing device to prevent fluid flow therethrough,
and sealing the tubing-casing annulus with a second sealing
apparatus above and spaced apart from the first sealing
apparatus.
[0010] The present invention, in certain embodiments, discloses a
through-tubing in-tubing system for providing a tubing/casing exit
above a first completion zone in a main wellbore for drilling a new
lateral wellbore from the main wellbore. In one embodiment in which
a tubing-casing annulus is initially sealed off at a lower end for
production below the tubing, another seal is provided within the
tubing-casing annulus above and spaced apart from the lower seal.
Then the tubing is perforated between the two seal areas,
preferably without perforating the casing. In one aspect a travel
joint, (including, but not limited to, a commercially available
ELTSR receptacle from Baker Oil Tools) part of which encompasses
the lower end of the tubing, is also perforated. Cement, resin or
other suitable hardenable material is then pumped from the surface,
down the interior of the tubing string, out through the
perforations, and up into the annulus between the tubing's exterior
and the casing's interior to such a level to stabilize a portion of
the tubing for making one or more exit openings in the tubing and
casing below that cement level.
[0011] The exit opening(s) are made with any suitable known
apparatuses, equipment and methods, including, but not limited to,
with a mill or mills, jet cutter(s), and explosives. In certain
aspects, a diverter, mill guide, and/or whipstock is positioned and
secured for directing a mill or mills against the tubing and/or
casing. A suitable mill or mills are then used to make the exit
opening(s) or window(s). In one aspect the mill or mills are run on
a string rotatable from the surface. In another aspect, a coiled
tubing string is used that includes a downhole motor for rotating a
mill. Such a coiled tubing string may be used within the tubing
that does not necessitate removal of the tubing string from the
well or removal of a wellhead at the surface. The emplacement of
the seal apparatus and perforating of the tubing can also be done
without removal of the wellhead.
[0012] Once the exit opening(s) are provided, a lateral wellbore
may be drilled out ("sidetracked") from the casing exit as desired.
The lateral wellbore may then be lined or cased as is well known in
the art.
[0013] In another embodiment, following sealing of the tubing,
cementing, and sidetracking, a jet cutter is lowered into the
tubing to sever the tubing above the sealing apparatus. The entire
tubing string is then raised at the surface and re-hung to provide
a desired gap, e.g. of 30 feet in length, at a desired location
down in the wellbore for installing a new upper primary
barrier.
[0014] In yet another embodiment, following sealing of the tubing,
cementing, and sidetracking as described above, an explosive device
according to the present invention is run into the tubing and
positioned adjacent the area at which a tubing gap is desired. One
or more selectively activatable holding subs, e.g. but not limited
to, the "button subs" or "hold downs" disclosed in U.S. Pat. No.
5,785,120, are activated by pumping fluid under pressure down the
tubing string to secure the explosive device in position.
Alternatively mechanical anchors or the like may be used. A fluid
pressure-activated firing head of the explosive device is activated
by pumping fluid under pressure down the tubing string. The firing
head simultaneously fires three separate charges: 1. a top charge
that severs the tubing at a top level; 2. a bottom charge that
severs the tubing at a bottom level; and 3. a slotting charge that
fires to produce a series of longitudinal slots and corresponding
fingers in and around the severed tubing. The explosive device is
connected at the end of a tubing or coiled tubing string which is
then lowered, pushing the housing of the explosive device down into
the remaining tubing. The button sub(s) hold the severed tubing
and, as the severed tubing is lowered, the fingers go down between
the tubing's exterior and the casing's interior, creating an open
axial gap in the tubing. The button sub(s) are then released and
the housing of the explosive device is retrieved from the tubing. A
sealing apparatus, e.g. an inflatable packer, a mechanical packer,
either of which may be a through-tubing packer is then run into the
tubing on a tubing string or on coiled tubing and positioned at the
gap in the tubing. Activating the packer seals off the
tubing/casing annulus. The string is then released from the packer
and retrieved from the wellbore.
[0015] In another embodiment a system with a mill and a downhole
motor on coiled tubing is positioned with a mill adjacent the
desired location for removal of a section of the tubing. The system
is secured in place within the tubing with any suitable securement
apparatus, including, but not limited to, one or more of the button
subs discussed above. The system also includes a movement or
stroking apparatus, e.g., but not limited to, as disclosed in FIGS.
1A-1E of U.S. Pat. No. 5,785,120 and accompanying text or in U.S.
application Ser. No. 09/183,943 filed Oct. 31, 1998. The coiled
tubing string includes a downhole motor that rotates the mill as
the stroking apparatus pulls the coiled tubing and, hence, the mill
upwardly to mill out the desired gap in the tubing. Depending on
the length of the stroke of the stroking apparatus and the length
of a desired milled gap in the tubing, more than one stroke may be
needed. Alternatively any known milling or cutting system and
method, including those in which a mill mills downwardly upwardly,
or both and is supported from the surface and/or within the tubing
below the surface may be used.
[0016] In any method described herein the stabilization and/or
perforating and cementing steps may be optional. It is also to be
understood that whenever a sealing apparatus is mentioned it may,
within the scope of this invention, be any known suitable
inflatable or mechanical packer (including but not limited to
hydraulically set packers, mechanically set packers, and
hydraulically set mechanical packers).
[0017] It is, therefore, an object of at least certain preferred
embodiments of the present invention to provide:
[0018] New, useful, unique, efficient, and novel and nonobvious
methods for re-completing a well above a previous completion
zone;
[0019] Such methods which do not require removal of a wellhead and
related equipment from a wellbore;
[0020] Such methods which provide a new primary barrier around a
tubing string above a new completion zone;
[0021] Such methods which do not require re-installation of a
drilling rig;
[0022] Such methods which employ stabilization of a portion of
tubing in a wellbore prior to making a tubing exit through that
tubing portion;
[0023] Such methods which do not require the removal of a tubing
string to provide a new exit above a previous completion zone in an
area through which a tubing string extends; and
[0024] Apparatus and equipment useful in such methods.
[0025] Certain embodiments of this invention are not limited to any
particular individual feature disclosed here, but include
combinations of them distinguished from the prior art in their
structures and functions. Features of the invention have been
broadly described so that the detailed descriptions that follow may
be better understood, and in order that the contributions of this
invention to the arts may be better appreciated. There are, of
course, additional aspects of the invention described below and
which may be included in the subject matter of the claims to this
invention. Those skilled in the art who have the benefit of this
invention, its teachings, and suggestions will appreciate that the
conceptions of this disclosure may be used as a creative basis for
designing other structures, methods and systems for carrying out
and practicing the present invention. The claims of this invention
are to be read to include any legally equivalent devices or methods
which do not depart from the spirit and scope of the present
invention.
[0026] The present invention recognizes and addresses the
previously-mentioned problems and long-felt needs and provides a
solution to those problems and a satisfactory meeting of those
needs in its various possible embodiments and equivalents thereof.
To one skilled in this art who has the benefits of this invention's
realizations, teachings, disclosures, and suggestions, other
purposes and advantages will be appreciated from the following
description of preferred embodiments, given for the purpose of
disclosure, when taken in conjunction with the accompanying
drawings. The detail in these descriptions is not intended to
thwart this patent's object to claim this invention no matter how
others may later disguise it by variations in form or additions of
further improvements.
DESCRIPTION OF THE DRAWINGS
[0027] A more particular description of embodiments of the
invention briefly summarized above may be had by references to the
embodiments which are shown in the drawings which form a part of
this specification. These drawings illustrate certain preferred
embodiments and are not to be used to improperly limit the scope of
the invention which may have other equally effective or legally
equivalent embodiments.
[0028] FIG. 1A is a side schematic cross-section view of a wellbore
with a casing and tubing string therein.
[0029] FIGS. 1B-1I are side schematic views in cross-section
showing a method according to the present invention.
[0030] FIG. 2 is a side schematic cross-section view of a wellbore
cutting system according to the present invention.
[0031] FIGS. 3A-3F are side schematic views in cross-section
showing a method according to the present invention employing the
system of FIG. 2.
[0032] FIGS. 4A-4D are side schematic cross-section views of a
wellbore cutting system according to the present invention.
[0033] FIGS. 5A and 5B are side schematic views of a sealing
apparatus for use with a system according to the present
invention.
[0034] FIGS. 5C and 5D are side schematic views of a system
according to the present invention using the apparatuses of FIGS.
5A and 5B.
DESCRIPTION OF EMBODIMENTS PREFERRED AT THE TIME OF FILING FOR THIS
PATENT
[0035] Referring now to FIG. 1A, an earth wellbore W is cased with
casing C extending down from the earth's surface to a completion
zone Z from which, originally, desirable hydrocarbons are produced.
Typical completion equipment is used for the zone Z. A tubing
string T within the casing C has a lower end R that terminates
above the completion zone Z. A packer P seals the tubing-casing
annulus. For convenience the wellbore W, although present, is not
shown in FIGS. 1B-IE and the lower end of the wellbore is also not
shown in FIGS. 1B-1I.
[0036] As shown in FIGS. 1B-1H in a method according to the present
invention, a system 10 is used to create an in-tubing lateral
wellbore L. As shown in FIG. 1B, the previously open lower end R of
the tubing T is sealed with a sealing apparatus 12 to prevent fluid
flow therethrough. This sealing apparatus may be any known suitable
device, e.g. a packer or a plug. The sealing apparatus 12 may be
installed using a wireline, coiled tubing, another jointed pipe or
tubing string movable through the tubing string T.
[0037] As shown in FIG. 1C an opening 14 has been made through the
tubing T (e.g. made by milling, with explosives or with a
perforation device) and, optionally, a centralizing device 16 has
been installed which is anchored within the tubing T. The
centralizing device 16 has arms 18 which contact the casing C and
centralize and stabilize the tubing T. The arms 18 are originally
collapsed so that the centralizing device 16 is movable down
through the tubing, e.g. on coiled tubing, on a wireline or on
another tubing string. The arms expand to centralize the tubing T,
particularly in an inclined wellbore if the tubing T is off-center
with respect to the casing and/or laying against the casing. A body
19 of the device 16 is hollow permitting fluid flow
therethrough.
[0038] As shown in FIG. 1D, wellbore cement 20 has been circulated
down through the tubing T (or through a workstring within the
tubing T such as a coiled tubing string), through the body 19 of
the centralizing device 16, out through the opening 14, and into a
tubing-casing annulus 22 to a level 24. The cement 20 is allowed to
set to stabilize the portion of the tubing T encompassed by the
cement 20. The cement 20: secures the lower end of the tubing T to
the casing C preventing relative movement between the two;
stabilizes the tubing T during subsequent milling or window
formation operations; defines a circulation path down the coiled
tubing and up the annulus for cuttings resulting from milling,
drilling, or milling-drilling; and provides a borehole path from
the interior of the tubing to the new wellbore exterior of the
casing through which a completion can be run into a lateral
wellbore. The cement stabilizes the tubing in the casing and closes
or fills voids around the tubing exterior so that the flow path
during later milling, drilling, and/or milling-drilling operations
has a defined confined flow area of known size so that circulating
fluid velocities can be sufficiently maintained to keep cuttings in
suspension and moving up-hole.
[0039] As shown in FIG. 1E a suitable guide, diverter, or whipstock
30 is run into the tubing T, e.g. on coiled tubing, wireline, or
another tubing string, and anchored in place. Any suitable known
guide, diverter, or whipstock may be used. Alternatively, openings
to be made through the tubing T, cement 20, and casing C may be
made with known explosives and explosive devices, with known
chemicals and chemical devices, or with known jetting cutters. The
guide, diverter, or whipstock may be a permanently set device, a
retrievable device, or a millable device.
[0040] As shown in FIG. 1F, an opening or window 40 is milled
through the tubing T with any suitable known mill or milling
system, as is a window 41 through the casing C and an opening 42
through the cement 20. The mill or mill system may also progress
into a formation 33 initiating a lateral wellbore 34. In one
particular aspect, the lateral wellbore 34 is extended to any
desired length employing suitable drilling and directional drilling
apparatuses. In one aspect the open hole section 35 is underreamed
to facilitate installation of a liner (in one aspect an expandable
liner) in the lateral wellbore 34. Optionally, the whipstock 30 may
now be removed.
[0041] As shown in FIG. 1G, a section 36 is cut out of the tubing T
with any known suitable cutter or mill. As with the other devices
used in the system 10, the cutter or mill may be used on coiled
tubing, a wireline, or another tubing string. Alternatively the
section, according to the present invention, can be removed with
known suitable explosives and explosive devices, chemicals and
chemical devices, and/or with known jetting cutters.
[0042] As shown in FIG. 1H, a liner 50 is installed with its lower
end 51 extending into the lateral wellbore 34. A sealing apparatus
52, including but not limited to any suitable known through-tubing
packer, is installed to seal off the tubing-casing annulus 22. In
certain preferred embodiments the sealing apparatus provides a
primary barrier. An expansion joint 53 (or polished bore receptacle
and seal assembly) located between tubing end 54 and sealing
apparatus 52 accommodates relative movement between the two, e.g.,
but not limited to, during subsequent production and injection
(e.g. injection of water or gas in an injection well). The top of
the lateral liner may be dropped off outside the window opening
and, optionally, not connected to the original tubing or casing.
Alternatively it may be attached to the tubing end 54 with a travel
joint 53 and packer 52 all secured to the top end of the liner 50.
Optionally, cement may be emplaced on top of the apparatus 52.
[0043] FIG. 1I shows schematically an alternative way to cement the
tubing-casing annulus 22 in which a perforation device 38 (e.g. any
known suitable perforator or perforating gun) perforates through
the tubing T (and through an optional travelling joint 39 if one is
present; such a joint may be used in the method of FIG. 1B). As in
FIG. 1D, cement is then circulated through the resulting
perforation or perforations into the annulus 22. The method shown
in FIG. 1I does not require the devices 16 or the formation of the
opening 14. The casing is, preferably, not perforated.
[0044] FIG. 2 illustrates schematically a tubing cutter system 60
according to the present invention useful in methods according to
the present invention described below. The system 60 includes a
selectively activatable firing initiator or head 61, selectively
activatable securement apparatus 62; explosives 63, 64, and 65; a
housing 66; and a lower end 67. The securement apparatus 62 may be
any suitable known wellbore anchoring apparatus or mechanism. As
shown, a plurality of "button subs" (as previously mentioned
herein) are used. The explosives 63 are used to sever a section of
the tubing at an upper level; the explosives 65 for severing the
section of tubing at a lower level; an the explosives 64 for
producing a series of longitudinal slots and corresponding fingers
around the severed tubing section. A detonation cord 68
interconnected between the head 61 and explosives provides for
simultaneously firing of all the explosives.
[0045] The system 60 is used, as shown in FIGS. 3A-3F to cut and
move a section of the tubing T (e.g. the section 36 as shown in
FIG. 1G). The system 60 is lowered within the tubing T to a desired
location (it being understood that the wellbore W of FIG. 3A is the
wellbore W of FIG. 1A and that the same completion zone Z, etc. are
present). The firing head 61 is activated (e.g. by a fluid pressure
pulse or by an electrical signal), firing the explosives 63, 64,
65. The tubing T is severed at a top level 47 and at a bottom level
48 creating a severed tubing section 46. Fingers 49 are formed with
slots between them. The fingers 49 are free to move outwardly. As
shown in FIG. 3B, lowering of the system 60, which is secured to
the severed tubing section 46 by the securement apparatus 62,
results in lowering of the severed tubing section 46. The lower
ends of the fingers 49 encounter an upper end 45 of the tubing T
and move outwardly as the system 60 and tubing section 46 are
lowered (see FIG. 3C). Optionally, a telescopically collapsing
apparatus as disclosed in U.S. Pat. No. 4,905,759 may be used as
the stroking movement apparatus to facilitate lowering of severed
casing. The pressure differential across the stroking apparatus's
piston then strokes the tubing section 46 downward without lowering
the coiled tubing.
[0046] As shown in FIG. 3D, pressure has been relieved releasing
the button subs and the system 60 has been removed and the severed
tubing section 46 has been lowered to expose a desired gap 44
between ends 45 and 43 of the tubing T. As shown in FIG. 3E a
selectively activatable sealing apparatus 70, (e.g. any suitable
known sealing device, packer, etc.) is moved down through the
tubing T and positioned between the tubing end 43 and a top end of
the severed tubing section. As shown in FIG. 3F, the sealing
apparatus 70 is activated to seal off the wellbore W. A tubular
string or coiled tubing supporting the sealing apparatus 70 is
released therefrom and retrieved from the wellbore.
[0047] FIGS. 4A-4D show a system 80 according to the present
invention useful in severing a tubing section (and creating a gap
in the tubing, e.g. as in FIG. 1G). The system 80 includes
selectively activatable securement apparatus 82 for selectively
anchoring the system 80 in tubing such as the tubing T; movement
apparatus 81 for moving part of the system 80 upwardly; a downhole
motor system 83 for rotating a mill system; and a mill system 84
for milling out the tubing section to create a desired gap therein.
The system 80 has a lower end 85. Appropriate internal flow
channels in the systems of the system 80 permit fluid to flow from
the top to the bottom of the system to selectively activate the
securement apparatus 82, to selectively activate and power the
movement apparatus 81, to selectively activate and power the
downhole motor system 83, and to selectively activate and power the
mill system 84. Fluid may flow out from a channel 86 through the
end 85.
[0048] The securement apparatuses 82 may be "button subs" as
previously mentioned herein which are selectively activatable by
pumping fluid under pressure down to the system 80 and through a
channel 87 in a top sub 88 that is in fluid communication with
fluid flow channels to the apparatuses 82.
[0049] The movement apparatus 81 may be any suitable downhole
movement apparatus. In one aspect the movement apparatus is a
stroke section mechanism as disclosed in U.S. application Ser. No.
09/183,943 filed Oct. 31, 1998, co-owned with the present invention
and incorporated fully herein for all purposes.
[0050] The downhole motor system 83 is any suitable known downhole
motor including, but not limited to a commercially available PDM
motor or MacDrill motor of Rotech Holdings, Ltd.
[0051] The mill system 84 may be any known suitable mill or mill
system, including, but not limited to, the tool of U.S. Pat. No.
5,735,359 issued Apr. 7, 1998, co-owned with the present invention
and incorporated fully herein for all purposes.
[0052] FIG. 5A shows a sealing apparatus 100 with a body 101, a
lower end or "stinger" 102, lower slips 103 for engaging a tubing's
interior, a packer element 104, upper slips 105 for engaging a
tubing's interior, locking teeth or threads 107 (or with typical
threads for threadedly engaging the apparatus 110), and seals
106.
[0053] FIG. 5B shows a sealing apparatus 110 with a body 111, a
lower end or "stinger" 112, a packing element 114, with locking
threads or teeth 117 for locking engagement with the teeth 107 of
the apparatus 100 (or with typical threads) and a seal bore 115
with an interior surface 116.
[0054] As shown in FIG. 5C, the apparatuses of FIGS. 5A and 5B may
be used to both provide the primary barrier above the end of the
severed tubing 55 (created as in FIG. 1G above) and to seal off the
annulus between the interior of the upper tubing end 54 and the
exterior of the apparatus 100. The apparatus 100 is connected to
and above the apparatus 110 and then the two are lowered on a
tubular string, wireline, or coiled tubing 120 so that the stinger
112 of the apparatus 110 enters the lower severed tubing end 55.
Optionally a running tool 130 may be used. The apparatuses are
configured, sized and positioned so that the packing element 114
when activated provides a primary barrier across the casing C and
the packing element 104 seals off the annulus between the interior
of the tubing end 54 and the exterior of the apparatus 100.
[0055] As shown in FIG. 5D, the slips 103, 105 of the apparatus 100
have been selectively activated as is well known in the art to
anchor the apparatus 100 in place in the tubing end 54; the stinger
102 has sealingly engaged the seal bore 115; the packing elements
104 and 114 have been selectively activated to effect the desired
sealing; and the string 120 has been released from the apparatus
100 and retrieved from the wellbore W.
[0056] Alternatively, the apparatus 110 may be moved into the
wellbore and located as shown in FIG. 5C and its packing element
activated. Then the apparatus 100 is lowered and positioned as
shown in FIG. 5C and its packing element is activated. The tubular
string (wireline, coiled tubing) 120 is then released from the
apparatus 100.
[0057] Each of the elements of the sytem described above has a
fluid flow channel therethrough from top to bottom to provide fluid
pumoped through the surface through the apparatus 100, through the
apparatus 110, and down into the tubing 55 and therebelow
selectively as desired. Either sealing apparatus in any system
disclosed herein may have appropriate landing surfaces or landing
nipples for receiving plugs or other apparatus pumped onto them.
These plugs may be any known suitable plug, with or without
anti-rotating structure, and/or they may be retrievable and/or
drillable.
[0058] The present invention, therefore, provides in certain, but
not necessarily all embodiments, a method for wellbore operations
in an earth wellbore with tubing within casing in an earth
wellbore, the wellbore extending down into earth from an earth
surface, the tubing including a tubing string with a lower end and
extending down within the casing with the lower end at a point
above a lower end of the casing, a tubing-casing annulus between
the tubing and the casing sealed by a first sealing apparatus, the
method including sealing the lower end of the tubing string with a
sealing device to prevent fluid flow therethrough, and sealing the
tubing-casing annulus with a second sealing apparatus above and
spaced apart from the first sealing apparatus. Such a method may
include one, some (in any possible combination) or all of the
following: making an exit opening or openings through the tubing
and an exit opening or openings through the casing, each exit
opening located above the first sealing apparatus; stabilizing the
tubing at a location above the first sealing apparatus; perforating
the tubing string at a level above a level of the first sealing
apparatus producing at least one perforation, introducing a
hardenable material into the tubing-casing annulus through the at
least one perforation and flowing the hardenable material within
said annulus up to a level spaced-apart from and above the level of
the first sealing apparatus; hardening the hardenable material;
wherein the hardenable material is cement; wherein the at least one
perforation is a plurality of perforations; wherein the wellbore
includes a first completion zone located below the lower end of the
tubing; wherein the second sealing apparatus is a primary barrier;
the first sealing device and the second sealing apparatus
constitute a primary barrier; wherein, prior to sealing the
tubing-casing annulus with the second sealing apparatus, the method
includes removing a section of the tubing above the first sealing
apparatus, moving the second sealing apparatus down through the
tubing to the area from which the section of tubing has been
removed, and activating the second sealing apparatus to seal off
the tubing-casing annulus; wherein the exit opening or openings are
made with a mill; wherein the mill is on a tubular string extending
from the earth surface and the mill is rotated for milling by the
tubular string; the mill is moved downwardly by moving the tubular
string downwardly or the mill is moved upwardly by moving the
tubular string upwardly, or both; wherein the mill is connected to
a downhole motor on a tubular string in the wellbore and the
downhole motor rotates the mill for milling and wherein the mill is
moved downwardly by moving the tubular string downwardly or wherein
the mill is moved upwardly by moving the tubular string upwardly,
or both; wherein the downhole motor is interconnected with movement
apparatus that is anchorable in the tubing at a point below the
earth surface, the movement apparatus for moving, upwardly and/or
downwardly, the downhole motor and mill during milling; wherein the
downhole motor is interconnected with movement apparatus anchorable
in the tubing at a point below the earth surface, the movement
apparatus for moving the downhole motor and the mill upwardly
and/or downwardly during milling; wherein the section of tubing is
made by explosive means for severing the tubing at two spaced-apart
locations; wherein the explosive means is on a movable tubular
string on the wellbore and includes a securement apparatus
securable within the tubing at the location of the section of
tubing to be removed, the securement apparatus remaining secured
with the section of tubing following severing of the tubing by the
explosive means, the method including lowering the section of
tubing to expose a gap in the tubing into which the second sealing
apparatus may be moved; making a tubing opening in the tubing above
the first sealing apparatus, installing a centralizer for
centralizing the tubing within the casing, the centralizer having a
hollow body through which hardenable material is pumpable out
through the centralizer, through the tubing opening, and into the
tubing-casing annulus; installing a whipstock within the tubing for
directing a mill for making the exit opening(s); removing the
whipstock after the exit openings are made; and/or drilling a
lateral wellbore from the exit opening through the casing;
installing a liner in at least a portion of the lateral
wellbore.
[0059] In conclusion, therefore, it is seen that the present
invention and the embodiments disclosed herein and those covered by
the appended claims are well adapted to carry out the objectives
and obtain the ends set forth. Certain changes can be made in the
subject matter without departing from the spirit and the scope of
this invention. It is realized that changes are possible within the
scope of this invention and it is further intended that each
element or step recited in any of the following claims is to be
understood as referring to all equivalent elements or steps. The
following claims are intended to cover the invention as broadly as
legally possible in whatever form it may be utilized. The invention
claimed herein is new and novel in accordance with 35 U.S.C. .sctn.
102 and satisfies the conditions for patentability in .sctn. 102.
The invention claimed herein is not obvious in accordance with 35
U.S.C. .sctn. 103 and satisfies the conditions for patentability in
.sctn. 103. This specification and the claims that follow are in
accordance with all of the requirements of 35 U.S.C. .sctn. 112.
The inventors may rely on the Doctrine of Equivalents to determine
and assess the scope of their invention and of the claims that
follow as they may pertain to apparatus not materially departing
from, but outside of, the literal scope of the invention as set
forth in the following claims.
* * * * *