U.S. patent application number 11/958756 was filed with the patent office on 2009-06-18 for system and method for monitoring scale removal from a wellbore.
Invention is credited to Robert Greenaway.
Application Number | 20090151936 11/958756 |
Document ID | / |
Family ID | 40751699 |
Filed Date | 2009-06-18 |
United States Patent
Application |
20090151936 |
Kind Code |
A1 |
Greenaway; Robert |
June 18, 2009 |
System and Method for Monitoring Scale Removal from a Wellbore
Abstract
A technique enables the cleaning of scale from a well and the
monitoring of scale removal. A scale removal tool and a radiation
detector are deployed simultaneously into a wellbore having scale
with a radioactive signature. The scale removal tool is used to
remove deposits from a well component, e.g. from the interior of a
tubular member. The radiation detector enables the measuring and
monitoring of scale removal. Data related to the scale removal can
be output for use by an operator to help optimize scale removal and
fluid flow.
Inventors: |
Greenaway; Robert; (Frimley,
GB) |
Correspondence
Address: |
SCHLUMBERGER TECHNOLOGY CORPORATION;David Cate
IP DEPT., WELL STIMULATION, 110 SCHLUMBERGER DRIVE, MD1
SUGAR LAND
TX
77478
US
|
Family ID: |
40751699 |
Appl. No.: |
11/958756 |
Filed: |
December 18, 2007 |
Current U.S.
Class: |
166/250.05 ;
166/66 |
Current CPC
Class: |
E21B 37/00 20130101;
E21B 47/11 20200501 |
Class at
Publication: |
166/250.05 ;
166/66 |
International
Class: |
E21B 37/00 20060101
E21B037/00 |
Claims
1. A method of performing a well cleanout, comprising:
simultaneously deploying a jetting tool and a gamma ray detector
downhole into a wellbore on coiled tubing; locating scale at a
wellbore location with the gamma ray detector; pumping a cleanout
material down through the coiled tubing and out through the jetting
tool to remove scale at a the wellbore location; and monitoring the
removal of scale with the gamma ray detector.
2. The method as recited in claim 1, wherein monitoring comprises
monitoring in real time.
3. The method as recited in claim 1, wherein pumping comprises
pumping the cleanout material through the gamma ray detector.
4. The method as recited in claim 1, further comprising outputting
data from the gamma ray detector to a surface acquisition unit.
5. The method as recited in claim 4, wherein outputting comprises
outputting the data along a communication line routed along an
interior of the coiled tubing.
6. The method as recited in claim 4, wherein outputting comprises
outputting the data along a fiber optic line routed along an
interior of the coiled tubing.
7. The method as recited in claim 6, further comprising measuring
temperature and pressure proximate the gamma ray detector; and
outputting temperature and pressure data to the surface acquisition
unit.
8. The method as recited in claim 4, wherein locating further
comprises measuring casing collar locations; and outputting casing
collar location data to the surface acquisition unit.
9. A system for use in a wellbore, comprising: a bottom hole
assembly having: a jetting tool comprising at least one jetting
nozzle oriented to direct a scale removal material against a well
component surface; a radiation detector positioned to detect and
locate scale buildup along the well component surface.
10. The system as recited in claim 9, wherein the radiation
detector comprises a gamma ray detector positioned to detect scale
buildup within a tubular.
11. The system as recited in claim 10, wherein the gamma ray
detector comprises a passage through which the scale removal
material passes as it flows to the jetting tool.
12. The system as recited in claim 9, further comprising a coiled
tubing string coupled to the bottom hole assembly to convey the
bottom hole assembly downhole.
13. The system as recited in claim 12, further comprising a surface
acquisition unit and a communication line connecting the radiation
detector with the surface acquisition unit.
14. The system as recited in claim 13, wherein the communication
line comprises a fiber optic line deployed within the coiled tubing
string.
15. A method, comprising: determining a location of a scale deposit
within an interior of a tubular positioned in a wellbore; removing
scale from an the interior of the tubular positioned in a wellbore;
monitoring scale removal with a radiation detector; providing data
on the scale removal in real time to a surface acquisition unit and
determining the extent of the remaining scale deposit.
16. The method as recited in claim 15, wherein monitoring comprises
monitoring scale removal with a gamma ray detector.
17. The method as recited in claim 15, wherein monitoring comprises
detecting the radioactive signature of barium sulfate.
18. The method as recited in claim 15, wherein removing comprises
directing a jet of fluid and beads against the scale.
19. The method as recited in claim 18, wherein directing comprises
directing sterling beads against the scale.
20. The method as recited in claim 15, wherein providing comprises
providing data through a communication line routed along a coiled
tubing string.
21. The method as recited in claim 15, wherein providing comprises
providing data through a fiber optic line routed along an interior
of a coiled tubing string.
22. A system, comprising: a surface acquisition unit; a coiled
tubing string; a communication line routed along the coiled tubing
string to communicate data to the surface acquisition unit; and a
bottom hole assembly coupled to the coiled tubing string and the
communication line, the bottom hole assembly comprising: a jetting
tool oriented for scale removal; and a gamma ray detector to
determine a location of scale and to monitor the extent of scale
removal.
23. The system as recited in claim 22, wherein the communication
line is routed along an interior of the coiled tubing string.
24. The system as recited in claim 22, wherein the bottom hole
assembly further comprises a monitoring section having temperature
and pressure sensors.
25. The system as recited in claim 22, wherein the gamma ray
detector comprises a flow passage to enable flow from the coiled
tubing, through the gamma ray detector, and to the jetting tool.
Description
BACKGROUND
[0001] In many well environments and applications, the development
of scale can be problematic for downhole completion equipment and
other downhole components. Scale can result from a variety of
deposits that form along the interior of tubulars, e.g. production
tubing or casing, or on other well related equipment. Scale often
is formed in oil or gas wells that produce water or as result of
water injection to enhance recovery. If left untreated, the scale
can inhibit or prevent fluid flow along the wellbore.
[0002] Several techniques have been used in the removal of scale
from tubing and other well equipment. For example, some types of
scale can be dissolved by a pumping specific treatment fluids
downhole. In other applications, scale is removed by directing a
jet of abrasive slurry against the scale to effectively chip away
at the scale deposits. In any of these approaches, difficulty
arises in determining the extent of the scale removal and thus the
success of the treatment.
SUMMARY
[0003] In general, the present invention provides a system and
method for cleaning scale from a well and for monitoring removal of
the scale. A scale removal tool and a radiation detector are
deployed simultaneously into a wellbore having scale with a
radioactive nature. The scale removal tool is operated to remove
scale from a well component, e.g. from the interior of a tubular
member. The radiation detector is utilized in locating scale
deposits, measuring the extent of the scale removal, and outputting
data related to the extent of scale removal.
BRIEF DESCRIPTION OF THE DRAWINGS
[0004] Certain embodiments of the invention will hereafter be
described with reference to the accompanying drawings, wherein like
reference numerals denote like elements, and:
[0005] FIG. 1 is a front elevation view of a well system deployed
into a wellbore for scale removal, according to an embodiment of
the present invention;
[0006] FIG. 2 is a schematic representation of a scale removal
bottom hole assembly deployed via a coiled tubing conveyance
system, according to an embodiment of the present invention;
[0007] FIG. 3 is a front elevation view of the bottom hole assembly
illustrated in FIG. 2, according to an embodiment of the present
invention;
[0008] FIG. 4 is a cut away view of a coiled tubing conveyance with
a communication line, according to an embodiment of the present
invention; and
[0009] FIG. 5 illustrates one example of a display for providing
information to an operator regarding scale removal, according to an
embodiment of the present invention.
DETAILED DESCRIPTION
[0010] In the following description, numerous details are set forth
to provide an understanding of the present invention. However, it
will be understood by those of ordinary skill in the art that the
present invention may be practiced without these details and that
numerous variations or modifications from the described embodiments
may be possible.
[0011] The present invention relates to a system and methodology
for determining the location of scale deposits and for monitoring
removal of the scale. The system and methodology enable the
accurate monitoring of scale removal through detection of the
radioactive nature of the scale. For example, barium sulfate has a
radioactive nature/signature that is detected and monitored to
determine the amount of scale remaining in a well component. A
radiation detector, such as a gamma ray detector, is used to detect
the radiation and output data to a surface acquisition unit
indicative of the amount of remaining scale.
[0012] In one example, data from the gamma ray detector is provided
along with a casing collar locator log to determine the presence
and location of barium sulfate scale. Gamma ray readings indicate
the presence of barium sulfate scale, and higher readings indicate
greater buildup of scale. A surface readout may be used to provide
operational information related to the cleanout procedure, and may
include a variety of parameters such as string weight, speed, pump
rate, and pressure. These parameters inform an operator as to
whether further cleanout progress remains feasible.
[0013] The system also can be designed to provide downhole data to
the surface in real time. By way of example, data from the
radiation detector and other downhole sensors can be transmitted
uphole via a communication line, such as a fiber optic line. Both
data from the radiation detector and data from other downhole
sensors, e.g. pressure sensors, temperature sensors, casing collar
locator detectors, can be sent uphole to a surface acquisition unit
to enable monitoring and/or optimization of the scale removal.
[0014] Removal of scale can be accomplished by pumping appropriate
scale removal materials downhole. If the cleanout equipment is
conveyed downhole by coiled tubing, fluid based scale removal
materials can be pumped down through the coiled tubing. In one
example, scale removal material is pumped under pressure through a
jetting tool used to direct high-pressure fluid through one or more
jetting nozzles and against the scale buildup. The scale removal
material may comprise combinations of liquid and particulate matter
able to remove scale buildup when directed against the scale under
pressure. For example, scale removal materials are available from
Schlumberger Corporation, of Houston, Tex., and include materials
containing sterling beads and cleanout gels or fluids designed to
enhance the removal of scale. As the scale is removed, the
radiation detector, e.g. gamma ray detector, is used to monitor the
removal process.
[0015] Referring generally to FIG. 1, one example of a well system
20 is illustrated according to an embodiment of the present
invention. In this example, well system 20 comprises a bottom hole
assembly 22 that may have a variety of components related to a well
cleanout procedure. For example, bottom hole assembly 22 may
comprise a radiation detector 24, e.g. a gamma ray detector, and a
scale removal tool 26, such as a jetting tool. The bottom hole
assembly 22 is moved downhole to a desired cleanout area 28 that
may have deposits 30 resulting from scale buildup. Commonly, the
deposits 30 are caused by barium sulfate or other scale forming
materials having a radioactive nature/signature.
[0016] In the example illustrated, the scale buildup 30 is formed
within a tubular member 32 through which bottom hole assembly 22 is
run downhole. However, bottom hole assembly 22 can be utilized in
the removal of scale deposits from other downhole components. The
tubular member 32 may comprise casing, production tubing,
completion tubing, or other tubular members deployed in a wellbore
34. As illustrated, wellbore 34 is lined with a wellbore casing 36,
and desired regions can be isolated along tubular member 32 by
locating one or more packers 36 between tubular member 32 and
wellbore casing 36.
[0017] As illustrated in FIG. 1, wellbore 34 extends down from
surface equipment 38 positioned at a surface location 40. Surface
equipment 38 may comprise a rig for deploying bottom hole assembly
22 on a conveyance 42. By way of example, conveyance 42 comprises
tubing, such as coiled tubing. A surface acquisition unit 44 is
positioned at surface location 40 and communicates with bottom hole
assembly 22 and its various sensors/detectors via one or more
communication lines 46. Communication lines 46 may comprise one or
more hardwired lines routed along conveyance 42 or, in some
applications, may comprise wireless communication lines.
[0018] The bottom hole assembly 22 is moved downhole to enable
radiation detector 24 to detect the presence of scale deposits 30.
Once detected, scale removal tool 26 is used to remove the scale
buildup, and radiation detector 24 is used to monitor the removal.
In the embodiment illustrated, scale removal tool 26 comprises a
jetting tool, and radiation detector 24 comprises a gamma ray
detector. A scale removal material is flowed under pressure
downhole, e.g. through coiled tubing conveyance 42, as represented
by arrows 48. The scale removal material is flowed through gamma
ray detector 24 to jetting tool 26. Jetting tool 26 directs the
pressurized scale removal material outwardly through one or more
jets 50 against scale deposits 30.
[0019] In embodiments that utilize a coiled tubing conveyance 42,
the bottom hole assembly 22 is conveyed downhole by a coiled tubing
injection system 52, as illustrated in FIG. 2. In this example,
coiled tubing injection system 52 comprises a coiled tubing reel 54
from which a coiled tubing conveyance 42 can be unspooled to convey
bottom hole assembly 22 downhole or spooled to withdraw the coiled
tubing conveyance and bottom hole assembly 22. The coiled tubing
reel 54 deploys coiled tubing through a coiled tubing injector 56
which orients and delivers the coiled tubing downhole into wellbore
34. Preferably, movement of the coiled tubing reel 54 and coiled
tubing conveyance 42 is controlled by a suitable surface control
unit 67 coupled to a suitable power source. Alternatively, movement
of the coiled tubing reel 54 and coiled tubing conveyance 42 can be
controlled by a suitable surface control unit 58 coupled to a power
source 60 and a pressure bulkhead 62.
[0020] Additionally, the communication line or communication lines
46 can be deployed downhole with conveyance 42. For example,
communication line 46 can be mounted on the coiled tubing or
deployed within the coiled tubing. The communication line 46 is
connected to surface acquisition unit 44 to receive data sent
uphole from bottom hole assembly 22. In the example illustrated,
surface acquisition unit 44 may comprise a computer based control
having a computer 64 with a suitable processor or processors
programmed to process data received from components of bottom hole
assembly 22. Computer 64 also can be used to process data received
from a variety of other sensors/components of well system 20.
Information on scale removal, pressure, temperature, casing collar
locations, and other data can be displayed on one or more displays
66 located at the well site or at other locations. In this example,
each display 66 uses a suitable graphical user interface to provide
scale removal information and other desired information in a format
useful to an operator. In some applications, computer 64 also can
be used to output data downhole to control various downhole
components.
[0021] Referring generally to FIG. 3, one embodiment of bottom hole
assembly 22 is illustrated. The bottom hole assembly 22 comprises a
variety of components that are used in removing scale and
monitoring the scale removal. The bottom hole assembly components
help optimize both scale removal and the subsequent fluid flow
through the member from which scale deposits are removed. The
number, type and arrangement of components can vary from one
application to another, however FIG. 3 illustrates an arrangement
suitable for many types of applications.
[0022] As illustrated, the scale removal tool 26 is a jetting tool
located at a lower position of bottom hole assembly 22. The jetting
tool 26 directs and discharges scale removal material through
jetting nozzle 50, as represented by arrows 68. A filter 70 is
positioned to filter the scale removal material before it enters
jetting tool 26. Filter 70 is designed to remove debris that can
potentially clog or damage jetting tool 26. A check valve section
72, having check valves 74, provides a well control pressure
barrier. Check valve section 72 may be located adjacent filter 70
on a side opposite jetting tool 26.
[0023] The illustrated bottom hole assembly 22 also comprises a
variety of sensors to detect and monitor a variety of downhole
parameters. For example, radiation detector 24, e.g. a gamma ray
detector, is positioned to detect radiation from the scale
deposits. The radiation detector 24 comprises a flow passage 76
through which scale removal material is flowed to jetting tool 26.
Other sensory devices may comprise a casing collar locator 78 and a
stress detector 80 for detecting tension and compression in bottom
hole assembly 22. As illustrated, casing collar locator 78 and
stress detector 80 are positioned between radiation detector 24 and
check valve section 72. Additionally, a monitoring section 82 may
comprise one or more pressure sensors 84 and temperature sensors
86. In many applications, pressure sensors 84 are positioned to
measure internal pressures within bottom hole assembly 22 and
external pressures outside bottom hole assembly 22.
[0024] Data from the radiation detector 24 and other sensors, as
well as control signals sent downhole from surface acquisition unit
44, are handled by an electronics section 88 that may be positioned
above radiation detector 24 and monitoring section 82. Electronics
section 88 is designed according to the surface acquisition system
utilized. By way of example, electronics section 88 may comprise a
bulkhead for terminating an optical fiber communication line, a
power section to provide downhole power storage, and a suitable
telemetry control for sending and receiving data. A connector 90 is
used to connect bottom hole assembly 22 to coiled tubing conveyance
42 or to another type of conveyance.
[0025] The use of coiled tubing for conveying bottom hole assembly
22 downhole creates an internal flow path along which the scale
removal material can be flowed downhole, while also providing a
structural feature along which the communication lines 46 can be
routed. As illustrated in FIG. 4, for example, conveyance 42
comprises coiled tubing 92 having an interior 94 that creates a
passage along which the scale removal material flows downhole. In
this example, communication line 46 is routed along interior 94 of
coiled tubing 92. However, communication line 46 also can be
attached to an exterior of the coiled tubing 92, or it can be
deployed within the wall forming coiled tubing 92. By way of
example, communication line 46 comprises a small protective tube 96
that surrounds one or more optical fibers 98. The optical fibers 98
enable telemetry between surface acquisition unit 44 and bottom
hole assembly 22. Data can be carried by optical fibers 98 both to
and from the surface acquisition unit 44.
[0026] During a scale removal operation, data from the various
sensors in bottom hole assembly 22 is provided to surface
acquisition unit 44, processed as necessary to a desired form, and
output to display device 66. For example, data from gamma ray
detector 24 can be output to the one or more display devices 66 in
a form that helps an operator identify and visualize scale build up
in tubular member 32. During scale removal, the gamma ray detector
24 can be continually operated to provide updated data to surface
acquisition unit 44. This allows an operator to monitor the scale
removal progress. A variety of other data, including temperature
data, pressure data, casing collar data and other information also
can be provided to surface acquisition unit 44 and displayed for
use and evaluation by an operator. Furthermore, the data can be
processed by computer 64 according to a variety of models or
algorithms to present additional information to an operator related
to scale removal and other aspects of the well.
[0027] FIG. 5 provides one example of a graphical user interface
100 that can be used to display information to an operator via
display 66. In this particular example, graphical user interface
100 displays information related to scale deposits 30 in tubular
member 32. By way of example, the graphical user interface 100
provides a graphical representation of the well 102 with features
illustrated in a manner helpful to an operator. The graphical
representation 102 illustrates the scale deposits 30 at a
particular depth based on information provided by gamma ray
detector 24. In addition or as an alternative, a graphical
representation 104 can be used to illustrate a gamma ray detector
log having data indicative of scale deposits at specific depths. Of
course, the data related to scale deposits can be illustrated or
presented in a variety of other formats. Additionally, the displays
66 can be used to provide the operator with other types of
information based on data from many types of sensors in bottom hole
assembly 22. As described previously, various software models and
algorithms can be run on computer 64 to process data obtained from
the downhole environment to provide additional well analysis,
including scale removal analysis. The resulting analysis is
displayed via graphical user interface 100 in a desired format.
[0028] As the scale removal operation progresses, the gamma ray
detector 24 is used to periodically or continuously measure the
radioactive nature of the scale deposit. The resulting data is
transmitted uphole to provide an operator with information on the
extent of the remaining scale deposit. In many applications, the
data can be transferred uphole in real time to keep an operator
updated throughout the scale removal operation. The real time
monitoring is particularly helpful in optimization of the scale
removal procedure. The surface acquisition unit 44 records and
displays the downhole information, allowing the operator to adjust
the depth of the bottom hole assembly and to compare real time
readings against an existing baseline well log to enable real time
optimization of the procedure.
[0029] The present system and methodology enable monitoring of
scale removal operations through detection of scale deposits based
on the radiation signature of the deposits. By using a gamma ray
detector, for example, the position and amount of barium sulfate
scale or other radioactive scale can be determined by the strength
of the radioactive signature. Also, the ability to output data to
surface acquisition unit 44 in real time facilitates immediate
optimization of the scale removal procedure. The scale removal is
further optimized by virtue of the internal flow passage extending
through the radiation detector and other bottom hole assembly
components to enable pumping of a variety of treatment fluids down
through a coiled tubing conveyance and through the bottom hole
assembly components to the scale removal tool 26. As a result of
the design and monitoring ability, both the scale removal material,
e.g. treatment fluid, and the jetting tool can be selected and
subsequently adjusted to optimize scale removal. In some
applications, the ability to use coiled tubing as the conveyance
enables and improves the functionality of a variety of
communication lines, such as fiber optic lines.
[0030] Accordingly, although only a few embodiments of the present
invention have been described in detail above, those of ordinary
skill in the art will readily appreciate that many modifications
are possible without materially departing from the teachings of
this invention. Such modifications are intended to be included
within the scope of this invention as defined in the claims.
* * * * *