U.S. patent application number 13/215379 was filed with the patent office on 2012-03-01 for reservoir pressure monitoring.
This patent application is currently assigned to BAKER HUGHES INCORPORATED. Invention is credited to John H. Clark, Philip G. Cooper, Randy L. Evans, Roger J. Marsh.
Application Number | 20120048539 13/215379 |
Document ID | / |
Family ID | 45695592 |
Filed Date | 2012-03-01 |
United States Patent
Application |
20120048539 |
Kind Code |
A1 |
Clark; John H. ; et
al. |
March 1, 2012 |
Reservoir Pressure Monitoring
Abstract
A method of completing a wellbore that includes providing
wellbore casing having shaped charges and permanent pressure gauges
on an outer surface of the casing. In an example of use, the casing
is inserted into the wellbore and cement is injected into an
annulus formed between the casing and wellbore. The shaped charges
are strategically deployed on the casing so they aim towards a wall
of the wellbore and are spaced apart along the casing. Thus
detonating the shaped charges creates perforations into a formation
around the wellbore and places the pressure gauges into pressure
communication with the formation. Pressure readings are delivered
to the surface from the pressure gauges in the form of signals.
Inventors: |
Clark; John H.; (Aberdeen,
GB) ; Cooper; Philip G.; (Aberdeen, GB) ;
Evans; Randy L.; (Sugar Land, TX) ; Marsh; Roger
J.; (Palmyra, AU) |
Assignee: |
BAKER HUGHES INCORPORATED
Houston
TX
|
Family ID: |
45695592 |
Appl. No.: |
13/215379 |
Filed: |
August 23, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61376327 |
Aug 24, 2010 |
|
|
|
Current U.S.
Class: |
166/250.01 ;
73/152.51 |
Current CPC
Class: |
E21B 47/06 20130101 |
Class at
Publication: |
166/250.01 ;
73/152.51 |
International
Class: |
E21B 47/06 20060101
E21B047/06 |
Claims
1. A method of characterizing a subterranean formation comprising:
a. providing a perforator in an annulus formed between a downhole
tubular and a wall of a borehole that intersects the subterranean
formation; b. using the perforator to form a perforation through
the wall and into the subterranean formation thereby communicating
pressure in the subterranean formation to the annulus; and c.
estimating pressure in the subterranean formation by measuring
pressure in the annulus.
2. The method of claim 1, wherein step (c) is performed over a
period of time and changes of pressure in the subterranean
formation over the period of time are monitored.
3. The method of claim 1, wherein the perforator comprises a device
selected from the group consisting of a shaped charge, a
perforating bullet, and a fluid jet.
4. The method of claim 1, wherein the step of measuring pressure in
the annulus comprises providing a pressure gauge in the annulus and
monitoring an output from the pressure gauge.
5. The method of claim 3, wherein the perforator comprises a
housing and the perforation extends into the housing so that an
inside of the housing is in pressure communication with the
subterranean formation, and wherein an input to the pressure gauge
is ported to the inside of the housing.
6. The method of claim 3, wherein the perforator comprises a
housing and the perforation extends into the housing so that an
inside of the housing is in pressure communication with the
subterranean formation, and wherein the pressure gauge is disposed
inside the housing.
7. The method of claim 1, wherein the subterranean formation
includes multiple zones, the method further comprising performing
steps (a)-(c) in at least two of the zones.
8. The method of claim 1, further comprising providing cement in
the annulus after step (a) and before step (b).
9. A system for measuring pressure in a subterranean formation
comprising: a perforator selectively disposed in an annulus formed
between a downhole tubular and a wall of a wellbore; a pressure
gauge in pressure communication with the perforator; and a coupling
mounted on the pressure gauge attached to a signal line, so that
when the perforator is initiated to create a perforation through
the wall of the wellbore, the pressure gauge is brought into
pressure communication with the formation and the pressure in the
formation can be measured through the signal line.
10. The system of claim 9, wherein the perforator comprises a
perforating gun with a shaped charge and wherein cement is provided
in the annulus and the perforation extends through a portion of the
cement.
11. The system of claim 9, further comprising tubing connected
between the pressure gauge and the perforator for providing
pressure communication between the pressure gauge and the
perforator.
12. The system of claim 9, further comprising a controller in
communication with the pressure gauge through the signal line and
in communication with the perforator through a signal line.
13. The system of claim 9, wherein the downhole tubular comprises
casing lining the wellbore and the perforator and the pressure
gauge are each clamped to an outer surface of the casing.
14. A method of measuring pressure in a formation adjacent a
wellbore lined with casing, the method comprising: a. providing a
shaped charge in an annulus between the casing and a wall of the
wellbore; b. providing a pressure gauge in the annulus and in
pressure communication with the shaped charge; c. forming a
perforation in the formation by projecting a jet from the shaped
charge into the formation from the annulus; d. sensing pressure of
the formation with the pressure gauge; and e. directing a signal
from the pressure gauge through a signal line that represents
pressure sensed in the formation.
15. The method of claim 14, wherein the shaped charge is included
within a perforating gun having a housing, and the pressure gauge
is in fluid communication with the shaped charge by a length of
tubing connecting the housing and the pressure gauge.
16. The method of claim 14, wherein the shaped charge is included
within a perforating gun having a housing, and the pressure gauge
is disposed in the housing.
17. The method of claim 14, further comprising repeating steps
(a)-(e), and wherein the perforation of step (c) is in a portion of
the formation that is isolated from the portion of the formation of
claim 14 by a formation barrier.
Description
RELATED APPLICATIONS
[0001] This application claims priority to and the benefit of U.S.
Provisional Application Ser. No. 61/376,327, filed Aug. 24, 2010,
the full disclosure of which is hereby incorporated by reference
herein.
BACKGROUND
[0002] 1. Field of Invention
[0003] The invention relates generally to the field of downhole
pressure measurement. More specifically, the present invention
relates to measuring formation pressure with permanent pressure
gauges mounted outside of wellbore casing and using shaped charges
mounted outside the casing to communicate pressure from the
formation to the gauges.
[0004] 2. Description of Prior Art
[0005] Formation pressure adjacent to a hydrocarbon producing
wellbore can be monitored to assess reservoir characteristics and
forecast future hydrocarbon production. Formation pressures are
also sometimes monitored for evaluating safety and environmental
concerns. Over time, more complex wells have been developed that
are deeper and include more elaborate lateral branches. As the
deeper and branched wells generally extend through more than one
formation, additional locations for pressure monitoring are
identified. As well production technology advances to allow deeper
and more complex well systems, similar advancements in pressure
monitoring have been made.
[0006] For open hole wellbores that have not yet been lined, tools
are sometimes inserted into the wellbore and a probe from the tool
penetrates into the adjacent formation to directly measure pressure
in the formation. Such characterization tools are impractical once
the wellbore has been lined. Thus after completion of the wellbore,
permanent pressure gauges are typically deployed inside the
wellbore casing for measuring the internal wellbore pressure.
SUMMARY OF INVENTION
[0007] Disclosed herein is a method of completing a wellbore that
includes providing wellbore casing having shaped charges and
permanent pressure gauges on an outer surface of the casing. In an
example of use, the casing is inserted into the wellbore and cement
is injected into an annulus formed between the casing and wellbore.
The shaped charges are strategically deployed on the casing so they
aim towards a wall of the wellbore and are spaced apart along the
casing. Thus detonating the shaped charges creates perforations
into a formation around the wellbore and places the pressure gauges
into pressure communication with the formation. Pressure readings
are delivered to the surface from the pressure gauges in the form
of signals.
[0008] Also disclosed herein is a method of characterizing a
subterranean formation. In one example the method of characterizing
includes providing a perforator in an annulus that is between a
downhole tubular and a borehole wall. The perforator is used to
form a perforation through the wall and into the subterranean
formation; thus the perforation allows communication of pressure in
the subterranean formation to the annulus. Pressure in the
subterranean formation is then estimated by measuring pressure in
the annulus. In one example embodiment, pressure measurements are
taken over a period of time so that changes of pressure in the
subterranean formation over the period of time can be monitored.
The perforator can be a shaped charge, a perforating bullet, or a
fluid jet. In one example embodiment, measuring pressure in the
annulus involves providing a pressure gauge in the annulus and
monitoring an output from the pressure gauge. In an example, the
perforator includes a housing and the perforation extends into the
housing so that an inside of the housing is in pressure
communication with the subterranean formation, and wherein an input
to the pressure gauge is ported to the inside of the housing. In an
optional embodiment, the perforator is made up of a housing and the
perforation extends into the housing so that an inside of the
housing is in pressure communication with the subterranean
formation, and wherein the pressure gauge is disposed inside the
housing. Optionally, the subterranean formation includes multiple
zones, in this example the method involves repeating the steps of
providing, perforating, and measuring in at least two of the zones.
Alternatively, cement is provided in the annulus after the
perforator is included but before the formation is perforated.
[0009] Further described herein is a system for measuring pressure
in a subterranean formation. In one example embodiment the system
is made up of a perforator selectively disposed in an annulus
formed between a downhole tubular and a wall of a wellbore and a
pressure gauge in pressure communication with the perforator.
Further included is a coupling mounted on the pressure gauge
attached to a signal line, so that when the perforator is initiated
to create a perforation through the wall of the wellbore, the
pressure gauge is brought into pressure communication with the
formation and the pressure in the formation can be measured through
the signal line. In an example embodiment, the perforator is a
perforating gun with a shaped charge, and cement is provided in the
annulus; as such, the perforation extends through a portion of the
cement. Tubing may optionally be provided that is connected between
the pressure gauge and the perforator for providing pressure
communication between the pressure gauge and the perforator. Yet
further optionally included is a controller in communication with
the pressure gauge through the signal line and in communication
with the perforator through a signal line. In another alternative
embodiment, the downhole tubular is casing that lines the wellbore
and the perforator and the pressure gauge are each clamped to an
outer surface of the casing.
[0010] Also described herein is a method of measuring pressure in a
formation adjacent to a wellbore lined with casing. In one example
the method involves providing a shaped charge in an annulus between
the casing and a wall of the wellbore, providing a pressure gauge
in the annulus and in pressure communication with the shaped
charge, forming a perforation in the formation by projecting a jet
from the shaped charge into the formation from the annulus, sensing
pressure of the formation with the pressure gauge, and directing a
signal from the pressure gauge through a signal line that
represents pressure sensed in the formation. In an alternate
embodiment, the shaped charge is included within a perforating gun
having a housing, and the pressure gauge is in fluid communication
with the shaped charge by a length of tubing connecting the housing
and the pressure gauge. Optionally, the shaped charge is included
within a perforating gun having a housing, and the pressure gauge
is disposed in the housing. The method can optionally be repeated,
and the perforation can occur in a portion of the formation that is
isolated from the first portion of the formation perforated by a
formation barrier.
BRIEF DESCRIPTION OF DRAWINGS
[0011] Some of the features and benefits of the present invention
having been stated, others will become apparent as the description
proceeds when taken in conjunction with the accompanying drawings,
in which:
[0012] FIG. 1 is a side sectional view of a system in a wellbore
for estimating pressure in a subterranean formation.
[0013] FIG. 2 is a side sectional view of the system of FIG. 1 with
cement added into the wellbore.
[0014] FIG. 3 is a side sectional view of the system of FIG. 2
forming perforations in the formation.
[0015] FIG. 4 is a side view of a sample embodiment of a pressure
gauge and perforator.
[0016] FIG. 5 is a side sectional view of a portion of a pressure
gauge of FIG. 4.
[0017] FIG. 6 is a side view of a perforator and pressure gauge on
an outer surface of a casing.
[0018] FIG. 7 is a side view of a perforator and pressure gauge on
an outer surface of a well bore casing.
[0019] FIG. 8 is a side sectional view of an alternate embodiment
of the system for measuring pressure in a subterranean
formation.
[0020] While the invention will be described in connection with the
preferred embodiments, it will be understood that it is not
intended to limit the invention to that embodiment. On the
contrary, it is intended to cover all alternatives, modifications,
and equivalents, as may be included within the spirit and scope of
the invention as defined by the appended claims.
DETAILED DESCRIPTION OF INVENTION
[0021] The present invention will now be described more fully
hereinafter with reference to the accompanying drawings in which
embodiments of the invention are shown. This invention may,
however, be embodied in many different forms and should not be
construed as limited to the illustrated embodiments set forth
herein; rather, these embodiments are provided so that this
disclosure will be thorough and complete, and will fully convey the
scope of the invention to those skilled in the art. Like numbers
refer to like elements throughout.
[0022] It is to be understood that the invention is not limited to
the exact details of construction, operation, exact materials, or
embodiments shown and described, as modifications and equivalents
will be apparent to one skilled in the art. In the drawings and
specification, there have been disclosed illustrative embodiments
of the invention and, although specific terms are employed, they
are used in a generic and descriptive sense only and not for the
purpose of limitation. Accordingly, the invention is therefore to
be limited only by the scope of the appended claims.
[0023] Referring now to FIG. 1, an example well bore 10 is shown in
a side sectional view having a casing string 12 inserted into the
well bore 10. The casing string 12 of FIG. 1 has perforating guns
14 attached on the outer surface of the casing string 12 that are
disposed in an annulus 16 formed in between the casing 12 and inner
wall of the well bore 10. In the embodiment of FIG. 1, each
perforating gun 14 includes a perforator 18 oriented so that it is
aimed away from the casing string 12 and into a formation 20
surrounding the well bore 10. Examples of perforators 18 include
shaped charges, perforating bullets, and fluid jets. It should be
noted that while the perforating gun 14 as shown contains a single
shaped charge, a perforating gun used for this application may
contain many shaped charges. In the example of FIG. 1, the
perforating guns 14 may be arranged so that the perforators 18
associated with each perforating gun 14 are spaced apart axially
within the well bore 10. The spacing of the perforators 18 can vary
depending on the particular formation 20 in which the well bore 10
is formed. It is believed it is well within the capabilities of
those skilled in the art to determine a designated spacing of the
perforators 18.
[0024] Pressure gauges 22 are further illustrated that are coupled
on the outer circumference of the casing string 12. In the example
embodiment of FIG. 1, a pressure gauge 22 is provided for each
perforating gun 14. However, other embodiments exist of the well
bore assembly of FIG. 1 wherein any number of pressure gauges 22
can vary from the number of perforating guns 14. As described in
more detail below, the pressure gauges 22 may be in communication
with the surface and optionally coupled with other pressure gauges
within the well bore 10.
[0025] FIG. 2 depicts cement 24 having been injected into the
annulus 16 of FIG. 1 for anchoring the casing string 12 within the
well bore 10. In the annulus 16, the cement 24 covers the outer
surfaces of the perforating guns 14 and pressure gauges 22.
Embodiments exist where the cement 24 is any substance flowable
into the annulus 16 and/or used for securing the casing string 12.
Moreover, the cement 24 may also be used to provide a barrier
preventing flow along the length of the annulus 16.
[0026] Referring now to FIG. 3, perforators 18 have been detonated
to form perforations 26 that extend through a portion of the cement
24 and into the formation 20 in a direction away from the casing
string 12. In one example, the perforating guns 14 include a single
perforator 18 with an associated detonator (not shown) for
initiating detonation of the perforator 18. In the example of FIG.
3, the perforator 18 is a shaped charge and has formed and directed
a jet 19 into the formation 20 to create the perforations 26.
Optionally, a digital switch (not shown) may be included with the
perforating guns 14 so each individual perforating gun 14 may be
independently fired. The perforations 26 provide pressure
communication from the formation 20 to the annulus 16.
Communicating pressure from the formation 20 into the annulus 16 in
turn communicates with the pressure gauges 22. Thus pressure in the
formation 20 may be monitored by the pressure gauges 22 via the
perforations 26. Accordingly, in one example embodiment the
pressure gauges 22 are mounted onto the casing string 12 adjacent
to the portion of the perforating guns 14 having the perforator 18
to maximize accuracy of pressure measurements in the formation 20.
Moreover, the permanent placement of the gauges 22 in the annulus
16 allows for pressure monitoring of the formation 20 over time,
where the time frame can be as discrete as minutes, up to multiples
of years, and all time frames in between. The ability to monitor
formation pressure over a time frame not only can help identify
transient issues downhole, but also be useful in estimating
production capacity of the formation and anticipated production
duration.
[0027] Further illustrated in the example of FIG. 3 are multiple
zones Z.sub.1-Z.sub.n, included within the formation. Barriers
B.sub.1-B.sub.n separate the zones Z.sub.1-Z.sub.n, from one
another, wherein the barriers B.sub.1-B.sub.n may block fluid flow
between adjacent zones Z.sub.1-Z.sub.n, and allow a pressure
gradient to form that is in excess of hydrostatic pressure. The
example embodiment of FIG. 3 depicts the perforating guns 14 and
pressure gauges 22 strategically located so that perforations 26
created by the perforators 18 are in separate zones Z.sub.1-Z.sub.n
thereby enabling discrete pressure measurements from more than one,
or each of, the zones Z.sub.1-Z.sub.n. Also, dimensions of a
hydrocarbon producing reservoir in the formation 20 can affect how
the pressure gauges 22 are strategically located. It is appreciated
that it is within the capabilities of those skilled in the art to
identify locations in a subterranean reservoir of hydrocarbons
where pressure measurements would provide information useful for
characterizing the reservoir. An advantage of strategically located
pressure measurements is the ability to measure pressure depletion
along a path where the borehole 10 intersects the formation 20;
which can be used for estimating reserves in the formation 20 and
also useful for maximizing recovery of hydrocarbons from the
formation 20.
[0028] In FIG. 4, example tandems 27 each made up of a perforating
gun 14 and a pressure gauge 22 are illustrated in a side view. The
tandems 27 of FIG. 4 represent a portion of the perforating guns 14
and pressure gauges 22 included with the casing string 12 disclosed
herein. As shown, tandems 27 are formed by coupling a perforating
gun 14 and pressure gauge with clamps 28. Initiation lines 30 are
shown connected to upper and lower ends of each perforating gun 14.
The initiation lines 30 may be cables that transmit a signal
instructing the firing head (not shown) within the perforating gun
14 to detonate the shape charge therein. Alternatively, the
initiation lines 30 may be detonation cord that once ignited at one
end transmits a detonation shock wave along the length of the
initiation line 30 for detonating shape charges within each
perforating gun 14. Signal lines 32 communicate pressure between
the pressure gauges 22 in the tandems 27 depicted in FIG. 4 and
also to the other tandems 27 with the casing string 12 thereby
forming a pressure gauge circuit. A coupling 33 is shown provided
with one of the pressure gauges 22 for attachment to the signal
line 32. Couplings 33 can be provided at each point where signal
lines 32 attach to the pressure gauges 22. A coupling 33 can be any
form of attaching the signal line 32 with the pressure gauge 22,
such as a male/female socket arrangement or simple contact of
conducting elements (not shown) in the signal line 32 with contacts
(not shown) in the pressure gauge 22. Further illustrated in FIG. 4
is tubing 34 coupled on one end to each pressure gauge 22 and on
its other end to the body of an associated perforating gun 14. As
such, pressure within the formation 20 communicates through the
perforation 26, into the body or bodies of the perforating guns 14,
and through the tubing 34 to each pressure gauge 22.
[0029] A controller 36 is further schematically illustrated in FIG.
4 shown disposed above the surface 37 and connected to ends of the
initiation and signal lines 30, 32. As such, the controller 36 of
FIG. 4 is in communication with the perforators 14 via the
initiation lines 30 and pressure gauges 22 via the signal lines 32.
Selective activation of the perforators 14 can be done using the
controller 36 as well as monitoring signals from the pressure
gauges 22 for collecting pressure data. The controller 36 can be an
information handling system that is stand alone or incorporated
within a surface truck (not shown).
[0030] Provided in a side view in FIG. 5 and taken along line 5-5
from FIG. 4, is an example embodiment of the pressure gauge 22
having a signal line 32 depending downward from a lower end of the
pressure gauge 22. The signal line 32 of FIG. 5 connects to another
pressure gauge (not shown) at a different elevation on the casing
string. Further illustrated in FIG. 5 is a pressure port 38 formed
through the outer body of the pressure gauge 22 that may optionally
be threaded and adapted to receive the tubing 34 of FIG. 4.
[0031] An alternative example embodiment of the well bore assembly
is shown in a side view in FIG. 6. In this example, a perforating
gun 14 is anchored onto the outer surface of the casing 12 and
initiation lines 30 attach to respective upper and lower ends of
the perforating gun 14. The pressure gauge 22 shown adjacent the
perforating gun 14 is anchored on the outer surface of the casing
string 12 thereby out of the path of a perforating jet that forms
upon detonation of the perforator 18. Tubing 34 connects the
pressure gauge 22 with the inside of the body of the perforating
gun 14. In one example, the pressure gauge is made of a device
having oscillatory quartz crystal that responds to pressure
variations so that pressure is experienced by pressure gauge 22 can
be converted into signals that are then transmitted to surface via
the signal line 32, or other communications means. Additionally, to
maximize penetration of the formation 20 with the perforation 26 at
0.degree. phase can be designated for creating the perforation 26
(FIG. 3). That is, a line generally coaxial with the perforation 26
extends substantially towards an axis A.sub.X of the casing 12
rather than at an angle with the axis A.sub.X.
[0032] In another embodiment provided in a side view in FIG. 7,
clamps 40 are shown coupling the perforating gun 14 with the outer
surface of the casing 12. Additional clamps 28 are shown attaching
the pressure gauge 22 to the perforating gun 14 to define a tandem
arrangement mounted on the casing string 12. Placement of the
clamps 28, 40 is variable depending on position of the tubing 34
and perforator 18.
[0033] In one example of use, as illustrated in FIG. 1, a casing
string 12 is provided with the perforating guns 14 and pressure
gauges 22 on its outer surface and then deployed into the well bore
10. Alternatively, the pressure gauges 22 may be housed inside the
perforating guns 14 and protected therein while inserting the
casing string 12 into the wellbore 10. The perforating gun 14 can
also shield the pressure gauges 22 during cement 24 injection, as
shown in FIG. 2. Further illustrating the example, after the cement
24 is set, the perforators 18 are detonated to produce perforations
26 in the formation 20. A sequence of perforator 18 initiation may
begin by first initiating the lower most perforator 18, and then
sequentially initiating each successive perforator 18 towards the
surface. By porting the pressure gauge to a void within the
perforating gun 14, pressure from the formation 20 is communicated
directly to each pressure gauge 22. Thus over time, pressure
monitored with the pressure gauges 22 may be analyzed to assess
characteristics within the formation 20, such as a prediction of
future or expected hydrocarbon production from within the well bore
10.
[0034] FIG. 8 illustrates in a side sectional view an alternate
embodiment of a system for measuring pressure in a subterranean
formation. In this example the casing 12A includes collars 42 where
adjacent sections of casing 12A are joined, such as by a threaded
fitting (not shown). In the example of FIG. 8 a perforator 18A and
pressure gauge 22A are set within the body of the collar 42. In the
embodiment of FIG. 8, at least a portion of the initiation lines
30A and signal lines 32A are routed through the collar 42.
[0035] The present invention described herein, therefore, is well
adapted to carry out the objects and attain the ends and advantages
mentioned, as well as others inherent therein. While a presently
preferred embodiment of the invention has been given for purposes
of disclosure, numerous changes exist in the details of procedures
for accomplishing the desired results. For example, components of
the perforating gun and pressure gauge could be integrated into a
single modular unit within a single housing. In this embodiment the
perforating gun components could be miniaturized to fit within a
housing that would normally only accommodate the pressure gauge.
These and other similar modifications will readily suggest
themselves to those skilled in the art, and are intended to be
encompassed within the spirit of the present invention disclosed
herein and the scope of the appended claims.
* * * * *