U.S. patent application number 13/913805 was filed with the patent office on 2014-12-11 for through casing coring.
The applicant listed for this patent is Baker Hughes Incorporated. Invention is credited to James Cernosek, Marcelo F. Civarolo, James C. Hunziker, Doug Mack.
Application Number | 20140360784 13/913805 |
Document ID | / |
Family ID | 52004506 |
Filed Date | 2014-12-11 |
United States Patent
Application |
20140360784 |
Kind Code |
A1 |
Hunziker; James C. ; et
al. |
December 11, 2014 |
Through Casing Coring
Abstract
Devices and methods for obtaining core samples from a formation
that surrounds a cased wellbore. A coring tool includes a casing
cutter for cutting an opening in the casing and a coring device for
obtaining a core sample from the formation.
Inventors: |
Hunziker; James C.; (New
Caney, TX) ; Cernosek; James; (Missouri City, TX)
; Civarolo; Marcelo F.; (The Woodlands, TX) ;
Mack; Doug; (Spring, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Baker Hughes Incorporated |
Houston |
TX |
US |
|
|
Family ID: |
52004506 |
Appl. No.: |
13/913805 |
Filed: |
June 10, 2013 |
Current U.S.
Class: |
175/58 ;
175/244 |
Current CPC
Class: |
E21B 29/005 20130101;
E21B 10/02 20130101; E21B 49/06 20130101 |
Class at
Publication: |
175/58 ;
175/244 |
International
Class: |
E21B 10/02 20060101
E21B010/02; E21B 49/02 20060101 E21B049/02 |
Claims
1. A coring tool for obtaining a core sample from a formation
surrounding a cased wellbore, the coring tool comprising: a casing
cutter for cutting an opening in casing lining the wellbore; and a
coring device for obtaining a core sample from the formation.
2. The coring tool of claim 1 further comprising a hole plugging
subassembly to close off said opening in the casing lining the
wellbore.
3. The coring tool of claim 1 wherein: the coring tool has an outer
housing having an opening therein; and the casing cutter and the
coring device are retained within a carrier that is moveable within
the outer housing between a first operational position wherein the
casing cutter is aligned with the opening in the coring tool
housing and a second operational position wherein the coring device
is aligned with the opening in the coring tool housing.
4. The coring tool of claim 3 wherein the carrier is rotatable
within the casing tool housing.
5. The coring tool of claim 1 wherein the casing cutter comprises a
casing cutting mill bit that is mounted upon a rotary cutting
device.
6. The coring tool of claim 1 wherein the coring device comprises a
coring bit that is mounted upon a rotary cutting device.
7. The coring tool of claim 1 wherein: the coring tool is
positioned by wireline manipulation to align the casing cutter with
a target position within the wellbore from which it is desired to
obtain a core sample; and the coring tool is then repositioned by
wireline manipulation to align the coring device with the target
position to obtain a coring sample from the target position.
8. A coring tool for obtaining a core sample from a formation
surrounding a cased wellbore, the coring tool comprising: a casing
cutter for cutting an opening in casing lining the wellbore; a
coring device for obtaining a core sample from the formation; and a
hole plugging subassembly to close off said opening in the casing
lining the wellbore.
9. The coring tool of claim 8 wherein: the coring tool has an outer
housing having an opening therein; and the casing cutter and the
coring device are retained within a carrier that is moveable within
the outer housing between a first operational position wherein the
casing cutter is aligned with the opening in the coring tool
housing and a second operational position wherein the coring device
is aligned with the opening in the coring tool housing.
10. The coring tool of claim 9 wherein the carrier is rotatable
within the casing tool housing.
11. The coring tool of claim 8 wherein the casing cutter comprises
a casing cutting mill bit that is mounted upon a rotary cutting
device.
12. The coring tool of claim 8 wherein the coring device comprises
a coring bit that is mounted upon a rotary cutting device.
13. A method of obtaining a core sample from a formation
surrounding a cased wellbore, the method comprising the steps of:
forming an opening in casing lining the wellbore; and obtaining a
core sample from the formation.
14. The method of claim 13 further comprising the step of closing o
the opening in the casing.
15. The method of claim 14 wherein the step of closing off the
opening in the casing further comprises actuating a hole plugging
subassembly to emplace a plug in the opening.
16. The method of claim 13 further comprising disposing the core
sample in a core sample receptacle within the coring tool.
17. The method of claim 13 wherein the step of forming an opening
in the casing comprises rotating a casing cutting bit to form a
circular cut within the casing.
18. The method of claim 13 wherein the step of obtaining a core
sample comprises rotating a coring bit to form a cylindrical core
sample and separating the core sample from the formation.
19. The method of claim 13 wherein: the step of forming an opening
in casing lining the wellbore further comprises locating the casing
cutter to be aligned with a target position from which it is
desired to obtain a core sample and actuating the casing cutter to
cut an opening in the casing; and the step of obtaining a core
sample from the formation further comprises locating the coring
device to be aligned with the target position and actuating the
coring device to obtain a core sample from the target position.
20. The method of claim 19 wherein the coring device is located to
be aligned with the target position by moving a bit box carriage
within an outer housing of the coring tool.
21. The method of claim 19 wherein the coring device is located to
be aligned with the target position by moving an outer housing
containing the coring device within the wellbore.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The invention relates generally to devices and methods for
obtaining core samples from the sidewall of a cased wellbore. The
device is also useful for obtaining cores from the sidewall of an
openhole wellbore.
[0003] 2. Description of the Related Art
[0004] Coring devices are more typically known for obtaining core
samples from the uncased sidewall of a wellbore. The inventors have
recognized that there might be an to advantage to evaluating
certain formation zones after a well has been cased.
SUMMARY OF THE INVENTION
[0005] The invention provides devices and methods for obtaining
core samples from the sidewall of a cased wellbore. In a described
embodiment, a coring tool is provided includes an outer housing
that encloses a plurality of bit boxes. The bit boxes are moveable
within the housing so that they may be selectively aligned with an
opening in the outer housing. In a particular embodiment, the bit
boxes are contained within a carriage that is axially moveable
within the outer housing between separate operational positions
wherein the tools within the bit boxes are selectively aligned with
a portion of the wellbore from which it is desired to obtain a core
sample.
[0006] In certain embodiments, the housing contains a first bit box
with a casing cutter having a casing cutting bit that is suitable
for cutting through the surrounding casing and cement. The housing
preferably also contains a second bit box with a coring device
having a coring bit that is suitable for cutting and obtaining a
core sample from the surrounding formation. Preferably also, the
coring device can articulate or move angularly to separate the core
sample from the formation. The separated core sample is preferably
deposited into a coring tube or receptacle within the coring tool
housing.
[0007] In particular embodiments, the coring tool contains a third
bit box that includes a device for placement of a casing plug into
the opening that was previously cut into the casing.
[0008] According to a further preferred feature of the invention,
the carrier is rotatable to within the outer casing of the coring
tool. An operator can rotate the carrier within the coring tool
housing in order to obtain core samples from other angular
locations within the wellbore. A coring tool in accordance with the
present invention can preferably be disposed within a wellbore on
wireline conveyance. Power and data communication with the coring
tool can then be conducted via the wireline. In particular
embodiments, the coring tool includes an electronic and power
section that controls and provides power to the casing cutter
device, the coring device and the hole plugging subassembly. In
addition, the coring tool preferably includes a power transfer
medium for movement of the carriage within the coring tool outer
housing.
[0009] The invention provides methods for obtaining coring samples
from cased wellbores. In exemplary operation, a coring tool is
disposed into a cased wellbore to a depth or location at which it
is desired to obtain one or more core samples. Stabilizers may be
set within the wellbore to secure the coring tool in place within
the wellbore. Thereafter, the carrier is axially moved within the
outer housing of the coring tool so as to selectively align first
the casing cutter device and then the coring device so that each of
these tools can operate at a preselected location and a core sample
is obtained. If desired, the carrier is then moved axially within
the outer housing to align the hole plugging subassembly with the
opening that was previously formed in the casing. The hole plugging
subassembly is then operated to secure a plug within the opening in
the casing. The devices and methods of the present invention allow
for multiple cores to be obtained from multiple locations.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] For a thorough understanding of the present invention,
reference is made to the following detailed description of the
preferred embodiments, taken in conjunction with the accompanying
drawings, wherein like reference numerals designate like or similar
elements throughout the several figures of the drawings and
wherein:
[0011] FIG. 1 is a side, cross-sectional view of an exemplary cased
wellbore with an exemplary coring tool disposed therein which is
constructed in accordance with the present invention.
[0012] FIG. 2 is an enlarged side, cross-sectional view of portions
of the coring tool shown in greater detail and being used to form
an opening in the wellbore casing.
[0013] FIG. 3 is a side, cross-sectional view of the portions of
the coring tool of FIG. 2, now in an operational configuration to
obtain a core sample from surrounding formation.
[0014] FIG. 4 is a side, cross-sectional view of the portions of
the coring tool shown in FIGS. 2 and 3, now in a configuration for
plugging an opening previously created in the surrounding
casing.
[0015] FIG. 5 is a detail view depicting a core sample being
obtained by a coring bit.
[0016] FIG. 6 is a schematic axial cross-sectional view
illustrating exemplary rotation of a bit box carrier within the
coring tool outer housing.
[0017] FIG. 7 depicts an alternative embodiment for an exemplary
coring arrangement wherein the coring tool is moved within the
wellbore to reposition cutting, coring and plugging components.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] FIG. 1 depicts an exemplary wellbore 10 that has been
drilled through the earth 12 from the surface (not shown). The
wellbore 10 is surrounded by a formation 14 at a lo depth from
which it is desired to obtain one or more sidewall core samples.
The wellbore 10 is lined with a metallic casing 16 which has been
secured in place with cement 18.
[0019] A coring tool 20 has been disposed within the wellbore 10 by
wireline 22, in a manner known in the art. The coring tool 20
includes a generally cylindrical outer housing 24 that encloses the
various components used to accomplish coring, as will be described.
An opening 26 is formed in the outer housing 24. Stabilizers 28, of
a type known in the art, have been extended radially outwardly from
the coring tool 20 to secure it within the wellbore 10. Preferably,
the stabilizers 28 maintain the coring tool 20 in proximity to one
side of the wellbore 10.
[0020] FIG. 2 depicts interior components of an exemplary coring
tool 20 as the coring tool 20 is being used to cut an opening in
the casing 16 and cement 18 lining the wellbore 10. The coring tool
20 includes an electronics and power section, indicated
schematically at 30. The electronics and power section 30 receives
electrical power for the coring tool 20 via the wireline 22. The
electronics and power section 30 may be electrically coupled to any
of the components in the coring tool 20 requiring electrical power
to operate. Also, the electronics and power section 30 may include
any number of electrical components to facilitate operation of
coring tool components. As depicted in FIG. 2, the electronics and
power section 30 includes a processing system 32 having at least
one information processor 34 of a type known in the art for
actuation and control of the various components of the coring tool
20. The electronics and power section 30 also includes transmitter
and receiver circuits 36 to convey information to surface and to
receive information and commands from the surface via a wireline
communication cable. Additionally, the electronics and power
section 30 includes a memory unit 38 for storing programs and
information processed by the processor 34 in order to operate the
various components of the coring tool 20. The electronics and power
section 30 may also include electronic components used for cooling,
radiation hardening, vibration and impact protection, potting and
other packaging details that do not require in-depth discussion as
they are known in the art. A data bus 40 is used to communicate
information between the various components of the electronics and
power section 30 as well as externally to a power transfer medium
42.
[0021] The electronics and power section 30 is operably associated
with a power transfer medium, schematically shown at 42. The power
transfer medium 42 may be selected according to the particular
power generating devices used to actuate and position bit boxes
within the coring tool housing 24. The power transfer medium 42 may
be a hydraulic fluid conduit where the power transfer device
includes a hydraulic pump. The power transfer medium 42 may be an
electrical conductor where the power generating device includes an
electrical power generator. Alternatively, the power transfer
medium 42 may be a drive shaft or gearbox where the power
generating device includes a mechanical power output for extending
a tool radially outwardly from the coring tool 20.
[0022] A bit box carriage 44 is retained within the coring tool 20
and is axially moveable and repositionable within the coring tool
housing 24 between multiple operational positions. In order to
ensure proper alignment and prevent undesirable radial movement of
the bit box carriage 44, a guide rail or track (not shown), of a
type known in the art, may be incorporated into the coring tool
housing 24 along which the bit box carriage 44 can slidably move.
One example of a suitable guide rail arrangement would be an
opposing pair of rigid plates. Each of the plates would have an
elongated slot formed therein, while the bit box carriage 44 would
have complimentary lugs that would ride within these slots.
However, other suitable guide rail or track arrangements could also
be used to help ensure precision alignment and movement of the bit
box carriage 44 within the housing 24. The bit box carriage 44
depicted in FIG. 2 contains two individual bit boxes: a casing
cutter bit box 46 and a coring bit box 48. The bit boxes 46 and 48
are each adapted to orient and extend a cutting tool radially
outwardly from the coring tool 20 through opening 26. In certain
embodiments, the bit box carriage 44 also includes a hole plugging
subassembly 50 that is located in a separate box 52 within the
carriage 44. The bit box carriage 44 can be moved axially within
the coring tool housing 24 by the power transfer medium 42, which
in turn may be actuated and controlled by the processing system 32
in accordance with a preprogrammed scheme. In FIG. 2, the bit box
carriage is oriented within the coring tool housing 24 such that
the casing cutter bit box 46 is aligned with the opening 26 of the
coring tool housing 24.
[0023] The casing cutter bit box 46 includes a casing cutter in the
form of a casing cutting mill bit 54 that is mounted upon a rotary
cutting device 56. The rotary cutting device 56 is capable of
rotating the cutting mill bit 54 and extending it radially
outwardly through the opening 26 and into cutting engagement with
the casing 16 lining the wellbore 10. The casing cutting mill bit
54 is preferably a generally cylindrical cutter with an open center
portion that is capable of forming a circular cut within the casing
16 and the cement 18. When the casing cutting mill bit 54 cuts
through the casing 16 and cement 18, the cutaway portions will
typically be retained within the open center portion of the bit 54
in this instance. Alternatively, the cutting mill bit 54 might be a
drill tip type cutter which forms an opening in to the casing 16
and cement 18 in the manner of a rotary drill. In certain
embodiments, the rotary cutting device 56 may also swivel to allow
the cutting mill bit 54 to be rotated between a position wherein
the bit 54 is facing away from the opening 26 (see phantom position
54a) and a position wherein the bit 54 is facing toward the opening
26 and can be extended toward the casing 16.
[0024] The coring bit box 48 is preferably located axially below
the casing cutter box 46 within the chassis 44. Also, the coring
bit box 48 preferably includes an opening 58 along its lower side
so that captured cores can be released into a core tube 60 within
the coring tool housing 24. The coring tool bit box 48 retains a
coring device in the form of a coring bit 62 which is capable of
cutting and capturing a core sample from the formation 14. Suitable
coring bits for this purpose are described in U.S. Pat. No.
7,373,994 entitled "Self Cleaning Coring Bit" and issued to
Tchakarov et al. This patent is owned by the assignee of the
present application and is hereby incorporated by reference in its
entirety. The coring bit 62 is mounted upon a rotary cutting device
64. The rotary cutting device 64 is capable of rotating the coring
bit 62 and extending it radially outwardly through the opening 26
and into cutting engagement with the formation 14 to obtain a core
sample. Additional details relating to the operation of rotary
coring tools to obtain a core sample from a wellbore sidewall are
described in U.S. Pat. No. 7,530,407 issued to Tchakarov et al.
This patent is owned by the assignee of the present application and
is hereby incorporated by reference in its entirety. Suitable
rotary cutting devices for this purpose include the MaxCOR.TM.
rotary sidewall coring system that is available commercially from
Baker Hughes Incorporated of Houston, Tex.
[0025] The hole plugging subassembly 50 includes a magazine 66
which contains one or more circular plugs 68. Each of the plugs 68
is shaped and sized to close of an opening in the casing 16 that
has been cut by the casing cutting mill bit 54. In addition, the
hole plugging subassembly 50 includes an extendable piston assembly
70 that can urge the plugs 68 within the magazine 66 outwardly so
that the outermost plug 68 is seated within such a milled
opening.
[0026] The bit box carriage 44 is selectively moveable between
axial operational positions within the housing 24 in order to
position the carriage 44 to enable it to perform operations that
will permit a core sample to be obtained from a cased wellbore 10
These positions are illustrated by FIGS. 2, 3 and 4. In FIG. 2, the
carriage 44 is positioned in a first operational position so that
the casing cutter bit box 46 is located proximate the opening 26 in
the housing 24 to allow the casing cutting mill bit 54 to cut an
opening in the casing 16 and cement 18 at a desired target position
Once an opening is formed in the casing 16 and cement 18, the
casing cutting mill bit 54 is withdrawn back into the coring tool
outer housing 24. The bit box carriage 44 is then axially shifted
by the power transfer medium 42 from the first operational position
shown in FIG. 2 to a second operational position, as illustrated in
FIG. 3.
[0027] When the coring tool 20 is in the second operational
position shown in FIG. 4, the coring bit box 48 is generally
aligned with the opening 26 in the coring tool housing 24. As
depicted in FIG. 3, the rotary cutting device 64 rotates the coring
bit 62 and extends the coring bit 62 outwardly through the opening
26 and into cutting engagement with the formation 14. As FIG. 5
depicts, a core sample 72 is formed as the coring bit 62 creates a
circular cut 74 in the formation 14. Articulation or angular
movement of the shaft 76 that retains the coring bit 62 (as
illustrated at 78) will break off the core sample 72 from the lo
formation 14. The core sample 72 can then be ejected into the core
tube 60 The core sample 72 will be brought to the surface when the
coring tool 10 is withdrawn from the wellbore 10.
[0028] FIG. 4 illustrates the coring tool 20 in a third operational
configuration wherein the carriage 44 has been aligned by the power
transfer medium 42 so that the box 52 is aligned with the opening
26 in the coring tool housing 24. The piston assembly 70 urges the
stack of plugs 68 radially outwardly until the outermost plug 68 is
seated into the opening 80 that was formed in the casing 18. The
plug 68 is preferably secured within the opening 80 by an
interference fit. It is noted that this step of plugging the
opening 80 in the casing 18 is not always required. If the coring
operation is being performed, for example, in a formation zone
wherein production is already occurring through perforated casing
16, then it is unnecessary to plug the opening 80.
[0029] In particular embodiments of the present invention, the
coring tool 20 is capable of obtaining multiple core samples from
the wellbore 10. In addition, the coring tool 20 is preferably
capable of plugging multiple openings 80 formed within the casing
16 of the wellbore 10. According to an exemplary embodiment, the
carriage 44 is capable of axial rotation with respect to the outer
housing 24 of the coring tool. A torsional motor 82 applies
rotational force to the carriage 44 to rotate it angularly within
the housing 24. FIG. 6 illustrates an embodiment for the coring
tool 10 wherein there are multiple openings 26 in the outer housing
24. Rotation of the carriage 44 thereby allows the cutting tools
54, 62 to be angularly aligned with each of the openings 26a, 26b,
26c, or 26d. Although there are four openings 26a, 26b, 26c, 26d
shown in FIG. 6, it should be understood that there may be more or
fewer than four such openings. The carriage 44 may be rotated in
the angular directions indicated by arrows 84 in FIG. 6. This
feature permits the carriage 44 to be repositioned so that it can
obtain further core samples.
[0030] If it is desired to obtain core samples from other depths or
locations within the wellbore 10, the stabilizers 28 can be unset
and the coring tool 20 then raised or lowered to another depth or
location within the wellbore 10 from which it is desired to obtain
further core samples. Thereafter, additional core samples can be
obtained in the manner previously described.
[0031] According to an exemplary method of operation, the coring
tool 20 is disposed into the wellbore 10 to a depth or location
within the cased wellbore 10 from which it is desired to obtain one
or more core samples 72. The stabilizers 28 are then set to secure
the coring tool 20 in place within the wellbore 10. The carriage 44
is positioned in the first operational position depicted in FIG. 2.
This may occur prior to running the coring tool 20 to its desired
depth or afterward. The rotary cutting device 56 is actuated so
that the casing cutting bit 54 cuts an opening 80 in the casing 16
of the wellbore 10. The carriage 44 is moved to the second
operational position depicted in FIG. 3. The rotary cutting device
64 then operates the coring bit 62 to obtain a core sample 72 from
the formation 14 that lies radially outside of the casing 16 and
cement 18. The core sample 72 is then disposed into a core tube 60
or other core sample receptacle. The carriage 44 may then be moved
to the third operational position depicted in FIG. 4. The hole
plugging subassembly 50 is then actuated to close off the opening
80 in the casing 16. If desired, an operator can then rotate the
carriage 44 within the outer housing 24 to align with other
openings, such as 26b, 26c or 26d and obtain additional coring
samples.
[0032] FIG. 7 illustrates an alternative arrangement for obtaining
a core from a cased wellbore 10. An exemplary coring tool 90 is
disposed within the wellbore 10 by wireline 22 suspension. The
coring tool 90 includes an outer housing 92 which contains bit
boxes 46, 48 which are preferably fixed against axial movement with
respect to the outer housing 92. In addition, the coring tool 90
preferably contains a hole plugging subassembly 50. The outer
housing 92 is provided with three lateral openings 94, 96, 98.
Opening 94 is aligned with the casing cutter rotary cutting device
56 so that the casing cutting mill bit 54 may be extended radially
outwardly through the opening 94. The mill bit 54 can cut an
opening in the casing 16 when aligned with a target point 100
(shown in phantom in FIG. 7) within the wellbore 10. Opening 96 is
aligned with the rotary cutting device 64 so that the coring bit 62
can be extended radially outwardly through the opening 96. The
coring bit 62 can obtain a core sample, as described above, when
the opening 96 is aligned with the target point 100. Opening 98 is
aligned with the hole plugging subassembly 50. The hole plugging
subassembly 50 can emplace a plug 68 within a previously-milled
opening within the casing 16 when the opening 98 is aligned with
the target point 100.
[0033] In operation, the coring tool 90 is moved axially upwardly
and downwardly within the wellbore 10 via wireline manipulation, as
illustrated by arrows 102 in order to align the appropriate lateral
openings 94, 96 or 98 with the target position 100 in order to
accomplish the tasks to obtain a core sample from the target
position 100 of the wellbore 10. First, the coring tool 90 is
positioned within the wellbore 10 so that the opening 94 is aligned
with the target position 100. Reversible slips or anchors (not
shown) of a type known in the art may be used to secure the coring
tool 90 in this position. Thereafter, the rotary cutting device 56
is actuated to cut an opening in the casing 16. The coring tool 90
is then repositioned in the wellbore 10, moving the coring tool 90
with the wireline 22 until the opening 96 is aligned with the
target position 100. Again, reversible slips or anchors may be used
to secure the coring tool 90 in this position. The cutting device
64 is actuated so that the coring bit 62 extends through the
opening in the casing 16 to obtain a core sample from the
surrounding formation. Next, the coring tool 90 is moved by
wireline 22 until the opening 98 is aligned with the target
position 100. Next, the hole plugging subassembly 50 is actuated to
emplace a plug 68 within the previously-formed opening in the
casing 16. Thereafter, one can remove the coring tool 90 from the
wellbore 10 via wireline retrieval.
[0034] Those of skill in the art will recognize that numerous
modifications and changes may be made to the exemplary designs and
embodiments described herein and that the invention is limited only
by the claims that follow and any equivalents thereof.
* * * * *