U.S. patent application number 11/860569 was filed with the patent office on 2009-03-26 for wireless casing collar locator.
Invention is credited to Clark Bergeron, Andy Cantrelle, Kelly Jackson, Scott Kruegel, Paulo S. Tubel.
Application Number | 20090078413 11/860569 |
Document ID | / |
Family ID | 40470403 |
Filed Date | 2009-03-26 |
United States Patent
Application |
20090078413 |
Kind Code |
A1 |
Tubel; Paulo S. ; et
al. |
March 26, 2009 |
WIRELESS CASING COLLAR LOCATOR
Abstract
A wireless casing collar locator includes a pipe coupling
detector configured to be conveyed through a wellbore. A detection
device is associated with the pipe coupling detector. The detection
device generates an output indicative of detection of a pipe
coupling in response to the output of the pipe coupling detector.
The locator includes an acoustic transmitter functionally
associated with the detection device. The transmitter is configured
to apply an acoustic impulse to a conveyance device used to move
the locator along the wellbore in response to communication to the
transmitter of the output of the detection device. A surface
receiver and processing unit used to convert acoustic energy into
electrical energy for processing in real time to determine the
location of the pipe detector in wellbores.
Inventors: |
Tubel; Paulo S.; (Spring,
TX) ; Jackson; Kelly; (Red Deer, CA) ;
Bergeron; Clark; (The Woodlands, TX) ; Cantrelle;
Andy; (The Woodlands, TX) ; Kruegel; Scott;
(The Woodlands, TX) |
Correspondence
Address: |
RICHARD A. FAGIN
P.O. BOX 1247
RICHMOND
TX
77406-1247
US
|
Family ID: |
40470403 |
Appl. No.: |
11/860569 |
Filed: |
September 25, 2007 |
Current U.S.
Class: |
166/255.1 ;
166/64 |
Current CPC
Class: |
E21B 47/09 20130101;
E21B 47/14 20130101 |
Class at
Publication: |
166/255.1 ;
166/64 |
International
Class: |
E21B 47/14 20060101
E21B047/14 |
Claims
1. A wireless casing collar locator, comprising: a pipe coupling
detector configured to be conveyed through a wellbore; a detection
device associated with the pipe coupling detector, the detection
device generating an output indicative of detection of a pipe
coupling in response to the output of the pipe coupling detector;
and an acoustic transmitter functionally associated with the
detection device, the transmitter configured to apply an acoustic
impulse to a conveyance device used to move the locator along the
wellbore in response to communication thereto of the output of the
detection device.
2. The locator of claim 1 further comprising an acoustic surface
receiver functionally associated with the downhole system that
converts the acoustic waves traveling through the conveyance into
an electrical signal for processing by an electronics system in
real time.
3. The locator of claim 1 wherein the pipe coupling detector
comprises a magnetic casing collar locator.
4. The locator of claim 1 wherein the detection device comprises a
pulse generator.
5. The locator of claim 1 wherein the acoustic transmitter
comprises a plurality of stacked piezoelectric disks.
6. The locator of claim 1 wherein the conveyance comprises a
slickline.
7. The locator of claim 1 further comprising an acoustic signal
detector in signal communication with the conveyance device
proximate the Earth's surface.
8. The locator of claim 7 wherein the acoustic signal detector
comprises an accelerometer.
9. A method for detecting a pipe coupling, comprising: moving a
pipe coupling detector along the interior of a pipe disposed in a
wellbore; conducting an output of the coupling detector to a signal
detector, the signal detector generating a pulse in response to
detection by the coupling detector of a pipe coupling in the
wellbore; conducting output of the signal detector to an acoustic
telemetry transmitter; and causing the transmitter to impart an
acoustic signal to an instrument conveyance device in response to
output of the signal detector.
10. The method of claim 9 further comprising detecting the acoustic
signal proximate the Earth's surface from the conveyance
device.
11. The method of claim 10 wherein the detecting the acoustic
signal comprises measuring acceleration of the conveyance
device.
12. The method of claim 9 wherein the conveyance device comprises
slickline
13. The method of claim 9 wherein the conveyance comprises coiled
tubing.
14. The method of claim 9 wherein the coupling detector comprises a
magnetic casing collar locator.
15. The method of claim 9 further comprising detecting the acoustic
signal proximate the Earth's surface and processing the signal
substantially in real time to determine positions of casing collars
in the wellbore.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] Not applicable.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not applicable.
BACKGROUND OF THE INVENTION
[0003] 1. Field of the Invention
[0004] The invention relates generally to the field of wellbore
instruments used to determine the position within a wellbore of
threaded connections between adjacent casing segments (or
"joints"). Such instruments are referred to in the art as "casing
collar locators", irrespective of whether the casing joints are
coupled to each other using internally threaded sleeve connectors
("collars") or alternating externally and internally threaded
casing joint ends ("pin" and "box" connections). More specifically,
the invention relates to casing collar locators that communicate to
the Earth's surface without using an electrical conductor or
optical fiber cable for a signal communication channel.
[0005] 2. Background Art
[0006] A casing collar locator is a instrument deployed in a
wellbore which finds or locates the collars or casing joint ends
which join together the individual joints to form a "string" of
well casing. After a wellbore has been drilled, and as part of the
wellbore completion procedure, the wellbore typically is "cased",
which means a length of steel or other high strength material pipe
is inserted into the wellbore and is typically cemented in place.
Casing is assembled by joining individual, discrete length segments
("joints") together end to end. The joints are normally joined
using an internally threaded coupling or "collar" which threads to
the externally threaded ends of each of a pair of adjacent casing
joints. The collar typically has a larger external diameter than
the casing joints and is thus easy to locate using magnetic
detection apparatus. Improvements in the design of threaded
couplings in some instances enables the collars to be omitted, by
incorporation of a different type of thread construction on the
longitudinal ends of the casing joints, namely, a "pin and box"
thread connection between adjacent joints. The pin end is
externally threaded and is inserted into the internally threaded or
"box" end of the adjacent casing joint. Pin and box casing
connections reduce the mass of metal proximate the threaded
connection. It provides a more uniform wall thickness while
reducing the mass of metal around the connection of joints.
[0007] It is important to correctly locate the collars or joints so
that the depth or location of a tool in the cased well can be
determined. Given the fact that casing joints have uniform spacing,
the depth of a particular instrument or device suspended in the
wellbore can be determined if the casing collars or joints can be
correctly counted.
[0008] An example of a casing collar locator that can generate an
electrical signal when the locator moves past a collar or past a
pin and box connection is described, for example, in U.S. Pat. No.
4,808,925 issued to Baird. Other types of casing collar locators
are well known in the art.
[0009] Irrespective of the configuration of the threaded connection
used in any casing string, as known in the art, it is necessary to
provide an electrical and/or optical signal channel to communicate
the output of the casing collar locator to the Earth's surface, so
that a record with respect to depth in the well of the collar
locator signal can be produced. For this reason, casing collar
locators are ordinarily used with "wireline", which is an armored
cable having at least one insulated electrical conductor therein.
There are configurations of wireline known in the art that also
include optical fibers.
[0010] It is known in the art to perform wellbore intervention
services using instrument conveyances that do not provide such
signal channel. Such conveyance methods include, for example,
coiled tubing, production tubing and slickline, for example. It is
known in the at to use electromagnetic signal communication (radio)
for signal communication over slickline. See, for example, U.S.
Pat. No. 7,224,289 issued to Bausov et al. It is believed that the
radio transmission device disclosed '289 patent may have limited
applicability in wellbores having highly conductive fluid therein,
particularly at great depth (in excess of about 5,000 feet). It is
also known in the art to make a slickline in the form of a tube
having an insulated electrical conductor therein. See, for example,
U.S. Pat. No. 5,495,755 issued to Moore. Making a slickline as
described in the Moore '755 patent is difficult and expensive, and
requires that a spooling device or winch, used to deploy the
slickline in the wellbore, include some form of slip ring or
similar device that enables the winch drum to rotate while making
electrical (or optical) connection to a rotationally fixed position
in the unit used to detect signals from the instrument in the
wellbore.
[0011] There continues to be a need for casing collar location
devices that do not require an electrical or optical signal channel
to communicate detection of a casing collar or connection to the
surface, and do not require modification of conventional "slickline
units" to include a slip ring or similar fixed-to-rotating
electrical and/or optical coupling.
[0012] The ability to know in real time the location of a tool
string in a well when the tool string is deployed using a coil
tubing or slickline is critical to compensate for the elongation of
the tubing string as it is deployed in the wellbore. The incorrect
determination of the location of the tool string when performing a
service in the wellbore can cause the string to fail in such
services as hydraulic fracturing work due to excessive pressure
that could be exerted onto the tool string.
SUMMARY OF THE INVENTION
[0013] A wireless casing collar locator according to one aspect of
the invention includes a pipe coupling detector configured to be
conveyed through a wellbore. A detection device is associated with
the pipe coupling detector. The detection device generates an
output indicative of detection of a pipe coupling in response to
the output of the pipe coupling detector. The casing collar locator
includes an acoustic transmitter functionally associated with the
detection device. The acoustic transmitter is configured to apply
an acoustic impulse to a conveyance device used to move the collar
locator along the wellbore in response to communication to the
acoustic transmitter of the output of the detection device when a
collar is detected.
[0014] A method for detecting a pipe coupling according to another
aspect of the invention includes moving a pipe coupling detector
along the interior of a pipe disposed in a wellbore. An output of
the coupling detector is conducted to a signal detector. The signal
detector generates a pulse in response to detection by the coupling
detector of a pipe coupling in the wellbore. Output of the signal
detector is coupled to an acoustic telemetry transmitter. The
transmitted is then caused to impart an acoustic signal to an
instrument conveyance device in response to output of the signal
detector.
[0015] Other aspects and advantages of the invention will be
apparent from the following description and the appended
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 shows an example of a casing collar locator being
conveyed into a wellbore by slickline.
[0017] FIG. 2 shows components of the casing collar locator of FIG.
1 in more detail.
[0018] FIG. 3 shows signal detection components disposed at the
Earth's surface for determining placement of a collar or other pipe
connection using the instrument shown in FIGS. 1 and 2.
DETAILED DESCRIPTION
[0019] A typical wellbore intervention operation including one
example of a casing collar locator 18 according to the invention is
shown in FIG. 1. The casing collar locator 18 may be disposed in a
sealed, pressure resistant housing (not shown separately) which
includes therein a pipe coupling detection device 18A and a signal
detection, processing and telemetry unit 18B. The foregoing device
18A and unit 18B will be explained in more detail with reference to
FIG. 3. In the present example, the casing collar locator 18 is
inserted into and withdrawn from a wellbore 10 drilled through
subsurface formations 12 at the end of a "slickline" 20. Slickline
is essentially a solid steel wire that is round in cross section.
It should be understood that the present invention may be used with
other forms of conveyance, such as tubing, coiled tubing, drill
pipe or the like, or any other conveyance that does not include an
electrical or optical signal channel for communicating signals from
the collar locator 18 to the Earth's surface.
[0020] The wellbore 10 includes a steel pipe or casing 14 inserted
therein. The casing 14 is typically formed by threadedly coupling
end to end a plurality of segments or "joints" of such pipe or
casing. In some examples, the casing joints include male threads
(pin ends) at both longitudinal ends, and the joints are threadedly
coupled by connecting two adjacent joints to a casing collar 16. A
casing collar is essentially an internally threaded sleeve
configured to mate with the pin (externally threaded) end of each
adjacent casing joint. It should be clearly understood that so
called "flush joint" casing having one end internally threaded (a
"box end") and configured to mate with the pin end of the adjacent
casing joint may also be used with the invention. One example of a
casing collar locator particularly suited to detect flush joint
threaded connections is described in U.S. Pat. No. 7,224,289 issued
to Bausov et al.
[0021] The slickline 20 can be extended from and withdrawn onto a
winch or similar spooling device (not shown separately) forming
part of a slickline unit 26. The slickline unit 28 may include a
spooling head 28 or similar laterally movable extension arm with
rollers (not shown) that enables the operator thereof to guide the
slickine 20 so that it is wound neatly on a winch drum (not shown).
In some examples, a motion detector 54, such as an accelerometer,
is coupled to the spooling head 28 such that an axial acceleration
of the slickline 20 is measured. As will be further explained with
reference to FIG. 3, the motion detector 54 may be used to detect
an acoustic signal imparted to the slickline 20 by the collar
locator 18 when a collar or threaded connection is detected. As
will be readily appreciated by those skilled in the art, the
slickline 20 can be passed through an upper sheave 22 and a lower
sheave 24 so that certain forces acting on the slickline 20 are
properly distributed. However, the configuration shown in FIG. 1
for inserting the slickline into the wellbore is not intended to
limit the scope of the invention.
[0022] In the example of FIG. 1, as the collar locator 18 is moved
past collars 16 or any other threaded coupling (e.g., "flush joint"
connections) of casing joint to casing joint, a magnetic field is
imparted to the casing 14 by one or more magnets (not shown) inside
the collar locator 18. A wire coil (not shown) is disposed
proximate the magnet and will have voltages induced therein when
the collar locator 18 passes by a casing collar 16. In the present
example, when a collar 16 is located by moving the collar locator
18 by a collar 16, the telemetry unit 18B imparts an acoustic wave
to the slickline 26 so that the position of the collar 16 can be
determined. The acoustic wave imparted to the slickline 20 is
detected by the motion detector 54, the output of which is coupled
to suitable detection and recording circuitry (collectively
referred to as a recording system 56) disposed inside the slickline
unit 26. The detected acoustic wave indicate the presence of a
casing collar or other type of threaded connection at the depth of
the collar locator 18 at the time of signal detection.
[0023] An example of circuitry that may be included in some
examples of a casing collar locator are shown schematically in FIG.
2. A pipe coupling detection device 32 may be any type of magnetic
casing collar locator device known in the art. One such collar
locator is described in U.S. Pat. No. 7,224,289 issued to Bausov et
al. as explained in the Background section herein. Such pipe
coupling detection devices include one or more magnets for inducing
a magnetic field in the casing, and a detection coil. Because of
the change in magnetic field distribution in the vicinity of
collars or threaded couplings, when a detection coil is moved
through such altered distribution magnetic field, a voltage is
induced in the coil. The detected voltage is interpreted to
determine the position of the threaded connection.
[0024] It is also possible to use contact arm-type caliper tools as
a pipe coupling detection device. One such contact arm caliper is
disclosed in U.S. Pat. No. 4,299,033 issued to Kinley et al. Inside
a pipe coupling, there is typically at least a small longitudinal
segment having a different internal diameter than the adjacent pipe
joints. Momentary increase in measured internal diameter may be
indicative of a pipe coupling.
[0025] Irrespective of the type of collar locator device used, the
output of the pipe coupling detection device 32 is coupled to a
detection circuit 34. The detection circuit 34 is configured to
determine from the signal sent from the pipe joint detection device
whether the device 32 has passed a connection between adjacent pipe
joints (collar or otherwise), and in response thereto provides a
pulsed output that is indicative of a casing collar or other
threaded connection in the casing (14 in FIG. 1). Output of the
detection circuit 34 is coupled to a controller 36, which may be
any microprocessor based controller. The controller 36 may be
programmed and reprogrammed by connection to an external signal
communication port 38 when the collar locator (18 in FIG. 1) is at
the Earth's surface. For example, the controller 36 may be
programmed to cause a telemetry transmitter (explained below) to
operate when an input pulse from the detection circuit 34 is
conducted to the controller 36. Electrical power to operate the
foregoing devices, and other devices to be explained further below,
may be provided by batteries 46.
[0026] During periods of time when the telemetry transmitter is not
operating, the batteries 46 charge, through a current regulator 44,
a bank of capacitors 42. The capacitors 42 store energy to be
released quickly through the telemetry transmitter to cause a large
amplitude acoustic pulse to be imparted to the slickline (20 in
FIG. 1). The capacitors 42 are also coupled to a transmitter driver
48. When instructed by the controller 36, the transmitter driver 48
couples the capacitors 42 to one side of transformer 50, the other
side of which is coupled to the acoustic transmitter. In the
present example, the acoustic transmitter can be a stack of
piezoelectric disk elements 52 in acoustic coupling with the collar
locator housing. When electrically actuated by application thereto
of the energy in the capacitors 42, the piezoelectric elements 52
generate an acoustic pulse which is ultimately imparted to the
slickline (20 in FIG. 1). In one example, the controller 36 and the
transmitter driver 48 are configured to cause the piezoelectric
elements 52 to emit a pulse of essentially monochromatic 1500 Hz
acoustic energy, such pulse corresponding to detection of a casing
collar or threaded coupling. Such acoustic pulse is detected at the
surface, as will be explained below with reference to FIG. 3.
[0027] The surface recording system 56 may include detection
circuitry configured to detect and interpret acoustic pulses
imparted to the slickline (or other conveyance) by the collar
locator (18 in FIG. 1). The previously mentioned accelerometer 54
is preferably mounted on the spooling arm or otherwise placed in
contact with the slickline (20 in FIG. 1) such that it is
responsive to axial motion of the slickline (20 in FIG. 1). The AC
(non zero frequency) output of the accelerometer 54 may be coupled
though a capacitance coupler 58 to a digital signal processing unit
("DSP") 64, such as one sold under model designation TMS320C33 by
Texas Instruments, Inc., Dallas, Tex. The DSP 64 is configured to
interpret the output of the accelerometer 54 to determine when an
acoustic pulse has been applied to the slickline (20 in FIG. 1) by
the casing collar locator (18 in FIG. 1). A power converter 60 may
convert standard house current or standard rig current (e.g., 120,
208, 240 or 480 volt AC) to suitable direct current for operating
the various devices in the recording system 56. Data output from
the DSP 64 may be conducted to a portable computer 66 such as a
notebook computer for making a record with respect to depth of the
detected casing collars or threaded couplings. An output driver 62
may provide signal output that can be used by a system operator or
system customer.
[0028] A casing collar locator system according to the invention
can provide casing collar or threaded coupling location in a
wellbore without the need to provide an electrical or optical
signal channel. Such capability may provide casing collar detection
in environments not well suited for electrical and/or optical
signal transmission.
[0029] While the invention has been described with respect to a
limited number of embodiments, those skilled in the art, having
benefit of this disclosure, will appreciate that other embodiments
can be devised which do not depart from the scope of the invention
as disclosed herein. Accordingly, the scope of the invention should
be limited only by the attached claims.
* * * * *