U.S. patent application number 14/543515 was filed with the patent office on 2016-05-19 for system and method for enabling the detection of fluid production and stimulation of a portion of a wellbore.
The applicant listed for this patent is Baker Hughes Incorporated. Invention is credited to Fahmi Bahrini, Rostyslav Dolog, Juan Carlos Flores, Othon R. Monteiro, Carlos A. Prieto, Pavan M.V. Raja.
Application Number | 20160138360 14/543515 |
Document ID | / |
Family ID | 55961234 |
Filed Date | 2016-05-19 |
United States Patent
Application |
20160138360 |
Kind Code |
A1 |
Dolog; Rostyslav ; et
al. |
May 19, 2016 |
System and Method for Enabling the Detection of Fluid Production
and Stimulation of a Portion of a Wellbore
Abstract
A system and method to isolate a portion of a wellbore and to
detect fluid production from the wellbore. The system includes
first and second isolators connected to a tubing string. The
isolators include memory shape elements positioned between sealing
elements and mandrels that may be actuated from a first shape to a
second shape to create a seal within the wellbore with the sealing
elements. The system may include a sensor configured to detect
production from the wellbore. A sensor may be configured to detect
a pressure of the isolated portion of the wellbore. A port between
the isolators may permit fluid communication to the portion of the
wellbore isolated by the sealing elements. The memory shape
elements may be actuated from the first shape to the second shape
at a first temperature and may actuated back to the second shape at
a second temperature
Inventors: |
Dolog; Rostyslav; (Houston,
TX) ; Prieto; Carlos A.; (Katy, TX) ; Flores;
Juan Carlos; (The Woodlands, TX) ; Monteiro; Othon
R.; (Houston, TX) ; Raja; Pavan M.V.;
(Houston, TX) ; Bahrini; Fahmi; (Houston,
TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Baker Hughes Incorporated |
Houston |
TX |
US |
|
|
Family ID: |
55961234 |
Appl. No.: |
14/543515 |
Filed: |
November 17, 2014 |
Current U.S.
Class: |
166/250.01 ;
166/191; 166/66 |
Current CPC
Class: |
E21B 47/06 20130101;
E21B 47/10 20130101; E21B 43/14 20130101; E21B 33/124 20130101 |
International
Class: |
E21B 33/124 20060101
E21B033/124; E21B 23/06 20060101 E21B023/06; E21B 43/25 20060101
E21B043/25; E21B 43/26 20060101 E21B043/26; E21B 47/00 20060101
E21B047/00; E21B 47/06 20060101 E21B047/06 |
Claims
1. A system to detect fluid production from an isolated zone
comprising: a tubing string; a first isolator connected to the
tubing string, the first isolator including at least one first
sealing element, a first mandrel, and at least one first memory
shape element positioned between the at least one first sealing
element and the first mandrel, wherein the at least one first
memory shape element may be actuated between a first shape and a
second shape to move the at least one first sealing element away
from the first mandrel; a second isolator connected to the tubing
string, the second isolator including at least one second sealing
element, a second mandrel, and at least one second memory shape
element positioned between the at least one second sealing element
and the second mandrel, wherein the at least one second memory
shape element may be actuated between a first shape and a second
shape to move the at least one second sealing element away from the
second mandrel; and wherein a portion of the wellbore is
substantially isolated when the at least one first memory shape
element and the at least one second memory shape element are each
actuated to the second shape.
2. The system of claim 1, further comprising a first sensor
configured to detect a production flow from a wellbore.
3. The system of claim 2, wherein the at least one first sealing
element further comprises a first plurality of sealing elements,
wherein the at least one first memory shape element further
comprises a first plurality of memory shape elements, wherein the
at least one second sealing element further comprises a second
plurality of sealing elements, and wherein the at least one second
memory shape element further comprises a second plurality of memory
shape elements.
4. The system of claim 2, further comprising a port between the
first isolator and the second isolator, the port in fluid
communication with an interior of the tubing string and wherein the
first sensor is configured to detect the production flow from the
isolated portion of the wellbore through the tubing string.
5. The system of claim 3, further comprising a second sensor
positioned between the first isolator and the second isolator,
wherein the second sensor is configured to monitor a pressure of
the isolated portion of the wellbore while the first plurality of
memory shape elements and the second plurality of memory shape
elements are each actuated to the second shape.
6. The system of claim 3, wherein the first and second plurality of
sealing elements are configured in a substantially circular
configuration and wherein the first and second plurality of sealing
elements have a first diameter when the first and second plurality
of shape memory elements are in their respective first shape and a
second diameter when the first and second plurality of shape memory
elements are in their respective second shape.
7. The system of claim 6, wherein the second diameter is larger
than the first diameter.
8. The system of claim 3, wherein each of the first and second
plurality of memory shape elements actuates from their respective
first shape to their respective second shape at a predetermined
first temperature.
9. The system of claim 8, wherein each of the first and second
plurality of memory shape elements actuates from their respective
second shape to their respective first shape at a predetermined
second temperature.
10. The system of claim 9, wherein the first temperature is at
least approximately five degrees Celsius greater than the second
temperature.
11. The system of claim 3, wherein the first and second plurality
of memory shape elements further comprises memory shape polymer
that actuates from their respective first shape to their respective
second upon contact with an actuating fluid.
12. A method of substantially isolating a portion of a wellbore
comprising: positioning an isolator adjacent a first portion of a
wellbore, the isolator comprising a first plurality of shape memory
elements operatively connected to a first plurality of sealing
elements and a second plurality of shape memory elements
operatively connected to a second plurality of sealing elements,
wherein the first and second plurality of shape memory elements are
in a respective first shape; actuating the first and second
plurality of shape memory elements of the isolator to move to a
respective second shape, wherein the actuation of the first and
second plurality of shape memory elements to their respective
second shapes engages the first and second plurality of sealing
elements against the wellbore to substantially isolate the first
portion of the wellbore; enabling detection of a production of
fluids from the isolated first portion of the wellbore.
13. The method of claim 12, wherein detection of the production of
fluids from the isolated first portion of the wellbore further
comprises measuring a fluid flow through a tubing string fluidly
connected to the isolated first portion of the wellbore via a port
in the isolator.
14. The method of claim 12, further comprising treating the
isolated first portion of the wellbore by pumping fluid through the
tubing string and out the port in the isolator.
15. The method of claim 14, wherein treating the isolated first
portion of the wellbore comprises re-fracturing a wellbore
formation.
16. The method of claim 14, wherein treating the isolated first
portion of the wellbore comprises restimulation of a wellbore
formation.
17. The method of claim 12, wherein detection of the production of
fluids from the isolated first portion of the wellbore further
comprises detecting a change in the production of fluid from the
wellbore due to the isolation of the first portion of the
wellbore.
18. The method of claim 17, further comprising monitoring a
pressure of the first portion of the wellbore while it is isolated
by the isolator.
19. The method of claim 12, wherein actuating the first and second
plurality of shape memory elements further comprises heating the
first and second plurality of shape memory elements to at least a
first predetermined temperature, wherein the first and second
plurality of shape memory elements actuates to their respective
second shape at approximately the first predetermined
temperature.
20. The method of claim 19, wherein heating the first and second
plurality of shape memory elements further comprises applying an
electric current.
21. The method of claim 20, wherein electric current is applied via
a battery located within the wellbore.
22. The method of claim 19, wherein heating the plurality of shape
memory elements further comprises pumping heated fluid down the
wellbore.
23. The method of claim 19, wherein heating the plurality of shape
memory elements further comprises transmitting radio frequency
waves or microwaves into the wellbore.
24. The method of claim 19, further comprising cooling the first
and second plurality of shape memory elements to a second
predetermined temperature, wherein each of the shape memory
elements actuates back to their respective first shape at
approximately the second predetermined temperature.
25. The method of claim 24, wherein the first predetermined
temperature is at least approximately fife degrees Celsius greater
than the second predetermined temperature.
26. The method of claim 12, wherein actuating the first and second
plurality of shape memory elements further comprises pumping a
fluid down the wellbore, wherein the exposure of the first and
second plurality of shape memory elements to the fluid actuates the
first and second plurality of shape memory elements.
Description
FIELD OF THE DISCLOSURE
[0001] The embodiments described herein relate to systems and
methods for enabling the detection of the production of fluids,
such as hydrocarbons, from an isolated zone of a wellbore and
potentially the stimulation of the isolated zone of the
wellbore.
BACKGROUND
Description of the Related Art
[0002] Various tools may be conveyed on a tubing string into a
wellbore for the diagnostic and/or treatment of a portion of the
wellbore. Multiple packers, or a single a straddle packer, may be
used to hydraulically isolate a portion of a wellbore. Packers are
often actuated to isolate a portion of a wellbore by movement of
the tubing string or may be actuated hydraulically. Movement of the
tubing string may limit the actuation of a single isolator within
the wellbore. Thus, a single isolator may need to be set and unset
multiple times to isolate more than one location within a wellbore.
It may also be required to run different tools into a wellbore in
order to isolate a portion of the wellbore, treat a portion of the
wellbore, and/or re-fracture a portion of the wellbore. Each trip
into the wellbore increases the production costs and may require
large amounts of time during which the wellbore may not be
producing hydrocarbons.
SUMMARY
[0003] The present disclosure is directed to systems and methods
for enabling the detection of the production of fluids, such as
hydrocarbons, from an isolated zone of a wellbore, evaluate the
zone, design a treatment program, and stimulate the zone that
overcomes some of the problems and disadvantages discussed
above.
[0004] One embodiment is a system to detect fluid production from
an isolated zone of a wellbore comprising a tubing string and a
first isolator connected to the tubing string. The first isolator
includes at least one first sealing element, a first mandrel, and
at least one first memory shape element positioned between the at
least one first sealing element and the first mandrel, wherein the
at least one first memory shape element may be actuated between a
first shape and a second shape to move the at least one first
sealing element away from the first mandrel. The system comprises a
second isolator connected to the tubing string, the second isolator
includes at least one second sealing element, a second mandrel, and
at least one second memory shape element positioned between the at
least one second sealing element and the second mandrel, wherein
the at least one second memory shape element may be actuated
between a first shape and a second shape to move the at least one
second sealing element away from the second mandrel and wherein a
portion of the wellbore is substantially isolated when the at least
one first memory shape element and the at least one second memory
shape element are each actuated to the second shape. The system may
comprise a first sensor configured to detect a production flow from
a wellbore and
[0005] The at least one first sealing element may comprise a first
plurality of sealing element, the at least one first memory shape
element may comprises a first plurality of memory shape elements,
the at least one second sealing element may comprise a second
plurality of sealing elements, and the at least one second memory
shape element may comprise a second plurality of memory shape
elements. The system may comprise a port between the first isolator
and the second isolator, the port being in fluid communication with
an interior of the tubing string and the first sensor may be
configured to detect the production flow from the isolated portion
of the wellbore through the tubing string. The system may comprise
a second sensor positioned between the first isolator and the
second isolator, the second sensor being configured to monitor a
pressure of the isolated portion of the wellbore while the first
plurality of memory shape elements and the second plurality of
memory shape elements are each actuated to the second shape.
[0006] The first and second plurality of sealing elements may be
configured in a substantially circular configuration and the first
and second plurality of sealing elements may have a first diameter
when the first and second plurality of shape memory elements are in
their respective first shape and a second diameter when the first
and second plurality of shape memory elements are in their
respective second shape. The second diameter may be larger than the
first diameter. The first and second plurality of memory shape
elements may actuate from their respective first shape to their
respective second shape at a predetermined first temperature. The
first and second plurality of memory shape elements may actuate
from their respective second shape to their respective first shape
at a predetermined second temperature. The first temperature may be
at least approximately five degrees Celsius greater than the second
temperature. The first and second plurality of memory shape
elements may comprise a memory shape polymer and may actuate from
their respective first shape to their respective second shape upon
contact with an actuating fluid.
[0007] One embodiment is a method of isolating a portion of a
wellbore comprising positioning an isolator adjacent a first
portion of a wellbore, the isolator comprising a first plurality of
shape memory elements operatively connected to a first plurality of
sealing elements and a second plurality of shape memory elements
operatively connected to a second plurality of sealing elements,
wherein the first and second plurality of shape memory elements are
in a respective first shape. The method comprises actuating the
first and second plurality of shape memory elements of the isolator
to move to a respective second shape, wherein the actuation of the
first and second plurality of shape memory elements to their
respective second shapes engages the first and second plurality of
sealing elements against the wellbore to isolate the first portion
of the wellbore. The method comprising enabling detection of a
production of fluids from the isolated first portion of the
wellbore.
[0008] The detection of the production of fluids from the isolated
first portion of the wellbore may comprise measuring a fluid flow
through a tubing string fluidly connected to the isolated first
portion of the wellbore via a port in the isolator. The method may
comprise treating the isolated first portion of the wellbore by
pumping fluid through the tubing string and out the port in the
isolator. Treating the isolated first portion of the wellbore may
comprise re-fracturing a wellbore formation. Treating the isolated
first portion of the wellbore may comprise restimulation of a
wellbore formation. The detection of the production of fluids from
the isolated first portion of the wellbore may comprise detecting a
change in the production of fluid from the wellbore due to the
isolation of the first portion of the wellbore. The method may
include monitoring a pressure of the first portion of the wellbore
while it is substantially isolated by the isolator.
[0009] Actuating the first and second plurality of shape memory
elements may comprise heating the first and second plurality of
shape memory elements to at least a first predetermined
temperature, wherein the first and second plurality of shape memory
elements actuates to their respective second shape at approximately
the first predetermined temperature. Heating the first and second
plurality of shape memory elements may comprise applying an
electric current. The electric current may be applied via a battery
located within the wellbore. Heating the first and second plurality
of shape memory elements may comprise pumping heated fluid down the
wellbore. Heating the first and second plurality of shape memory
elements may comprise transmitting radio frequency waves or
microwaves into the wellbore. The method may include cooling the
first and second plurality of shape memory elements to a second
predetermined temperature, wherein each of the shape memory
elements actuates back to their respective first shape at
approximately the second predetermined temperature. The first
predetermined temperature may be at least approximately five
degrees Celsius greater than the second predetermined temperature.
Exposure of the first and second plurality of shape memory elements
to a fluid pumped down the wellbore may actuate the first and
second plurality of shape memory elements.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 shows an embodiment of an isolator comprised of
memory shape elements in a first or initial shape.
[0011] FIG. 2 shows the isolator of FIG. 1 with the memory shape
elements in a second or actuated shape.
[0012] FIG. 3 shows tubing string positioning an embodiment of an
isolator with two isolating elements within a wellbore.
[0013] FIG. 4 shows the tubing string of FIG. 3 with the isolating
elements being actuated to hydraulically isolate a portion of the
wellbore.
[0014] FIG. 5 shows the tubing string of FIG. 3 monitoring the
production of the wellbore while the portion of the wellbore is
selectively isolated by the actuated isolating elements.
[0015] FIG. 6 shows the tubing string of FIG. 3 monitoring the
production from the portion of the wellbore being selectively
isolated by the actuated isolating elements.
[0016] FIG. 7 shows the tubing string of FIG. 3 used to stimulate
and/or re-fracture the formation adjacent the isolation portion of
the wellbore.
[0017] FIG. 8 shows show a flow chart of one embodiment of a method
of isolating a portion of a wellbore.
[0018] FIG. 9 shows a tubing string with multiple isolating
elements located along the tubing string that may be actuated to
isolate multiple portions of a wellbore.
[0019] While the disclosure is susceptible to various modifications
and alternative forms, specific embodiments have been shown by way
of example in the drawings and will be described in detail herein.
However, it should be understood that the disclosure is not
intended to be limited to the particular forms disclosed. Rather,
the intention is to cover all modifications, equivalents and
alternatives falling within the scope of the invention as defined
by the appended claims.
DETAILED DESCRIPTION
[0020] FIG. 1 shows an embodiment of an isolator 100 that includes
memory shape elements 150 that may be used to repeatedly move
sealing elements 110 and 120 from a position towards a mandrel 145
to a position away from the mandrel 145. The isolator 100 may be in
a set or engaged configuration when the sealing elements 110 and
120 are positioned away from the mandrel 145 and the isolator 100
may be in an unset or unactuated configuration hen the sealing
elements 110 and 120 are positioned towards the mandrel as
discussed herein. FIG. 1 shows the isolator 100 in an unset or
unactuated configuration. In the unset configuration, the isolator
100 may have a first outer diameter 102A.
[0021] The isolator 100 may include a mandrel 145 having an inner
diameter 101 and an outer ring of components 125 with an inner ring
of components 135. The mandrel 145, outer components 125, and inner
components 135 may be solid components and may be comprises of
various hard materials, such as metal. The outer components 125 may
be connected together with a plurality of deformable elements 110
to form a single ring. The deformable elements 110 may be comprised
of various deformable materials, such as rubber, as would be
appreciated by one or ordinary skill in the art. A plurality of
sealing elements 120 may be connected to the exterior surfaces of
the outer components 125 as shown in FIG. 1. The sealing elements
120 may be comprised of various materials that permit the creation
of a seal when pressed against a wellbore, casing, or tubing. For
example, the sealing elements 120 may be comprised of rubber, but
could be various other materials as would be appreciated by one of
ordinary skill in the art having the benefit of this disclosure.
The shape and configuration of the isolator 100 and components is
for illustrative purposes only and may be varied depending on
application as would be appreciated by one of ordinary skill in the
art having the benefit of this disclosure.
[0022] The outer elements 125 are connected to the exterior of the
mandrel 145 via a first plurality of shape memory elements 150.
Likewise, the inner elements 135 are connected to the exterior of
the mandrel 145 via a second plurality of shape memory elements
150. The shape memory elements 150 are comprised of various shape
memory alloys that move from a first shape to a second shape upon
reaching a predetermined temperature. As shown in FIG. 1, the shape
memory elements 150 are at a temperature below a first temperature
and thus, the shape memory elements 150 are still in a first or
unactuated shape. As discuss herein, once the shape memory elements
150 are heated to the first temperature the shape memory elements
150 will move to, and stay in, a second shape (shown in FIG. 2)
until the temperature is cooled to a second temperature. The shape
memory elements 150 may be configured so that a change in degrees
between the first and second temperatures is required to actuate
the shape memory elements 150, such as five (5) degrees Celsius,
ten (10) degrees Celsius, twenty five (25) degrees Celsius, fifty
(50) degrees Celsius, or even more, if desired. The plurality of
memory shape elements 150 may comprise the inclusion of an
expandable or elastic sheet.
[0023] FIG. 2 shows an embodiment of the isolator 100 in a set or
actuated state. The memory shape elements 150 have been heated to,
or beyond, the first temperature so that the memory shape elements
150 have moved to a second shape moving the sealing elements 110
and 120 away from the mandrel 145. The inner diameter 101 of the
mandrel 145 may remain constant whereas the outer diameter 102B of
the isolator 100 may be increased due to the movement of the memory
shape elements 150 to the second shape. The shape memory alloys may
be capable of generating up to 40,000 PSI of force, which may be
sufficient to create and retain a seal between the sealing elements
110 and 120 and a portion of the wellbore. Alternatively, the
memory shape elements 150 may be configured so that the second
temperature is hotter than the first temperature, if desired.
[0024] The isolator 100 may not include inner components 135 and
outer components 125 that are both connected to the mandrel 145.
Instead, the memory shape elements 150 may connect the sealing
elements 110 and 120 in various configurations as would be
appreciated by one of ordinary skill in the art having the benefit
of this disclosure. For example, a single ring of solid members may
be connected to the mandrel 145 via the shape memory elements 150
with sealing elements 110 connected to the exterior of the single
ring of solid members.
[0025] The shape memory elements 150 may be heated in various ways
to actuate to the second shape as would be appreciated by one of
ordinary skill in the art. For example, fluid may be pumped down
the wellbore to heat the shape memory elements 150; the elements
150 could be heated via electricity from either the surface or a
downhole battery; the elements 150 could be heated via the
transmission of microwaves, electromagnetic radiation, or a radio
frequency to the isolator 100; and/or various other mechanisms.
Alternatively, the shape memory elements 150 may be comprised of a
shape memory polymer that is actuated from a first shape to a
second shape upon contact of a specific fluid. Thus, the specified
fluid may be pumped and retained in the wellbore when it is
desirous to isolate a portion of a wellbore using one or two
isolators comprising shape memory elements 150.
[0026] The shape memory elements 150 may be comprises of various
materials that move between different shapes depending on the
temperature of the element 150. The shape memory elements 150 may
be configured so that when the elements 150 are heated to a first
temperature the element 150 may move from a first or initial shape
to a second shape, which may be used to engage the sealing elements
110 and 120 of the isolator 100 with a wellbore to create a seal.
The engagement of the sealing elements 110 and 120 of the isolator
100 may substantially isolate or restrict a portion of the
wellbore. The elements 150 may be configured so that the element
remains in the second shape until the temperature cools to a second
temperature at which the elements 150 revert back to their first or
initial shape. The movement back to the first or initial shape may
be used to unset the isolator 100 from the wellbore. The material
of the memory shape elements 150 may be configured so that the
second temperature is at least 5 degrees Celsius lower than the
first temperature. As discussed above, the shape memory elements
150 may be comprised of various materials as would be appreciated
by one of ordinary skill in the art having the benefit of this
disclosure. For example, the shape memory elements 150 may be
comprised of, but not limited to, nickel titanium alloy, nickel
titanium zirconium alloy, titanium nickel copper alloy, copper
aluminum manganese alloy, iron nickel cobalt aluminum tantalum
boron alloy, copper aluminum niobium alloy, nickel manganese
gallium alloy, zirconium copper alloy, polycrystalline iron nickel
cobalt aluminum alloy, polycrystalline iron manganese aluminum
nickel alloy, polycrystalline nickel titanium zirconium niobium
alloy, titanium hafnium nickel rhenium alloy, iron manganese alloy,
zirconium copper alloy, iron manganese cobalt alloy, or cobalt
aluminum alloy.
[0027] FIG. 3 shows an isolator having a lower isolation element
100A and an upper isolation element 100B, herein after referred to
as upper and lower isolators, connected to tubing string 7 and
positioned within a portion of a wellbore 1. The tubing string 7
may be used to position the isolators 100A and 100B adjacent a
portion of the wellbore 1 that it may be desired to determine the
hydrocarbon production being produced by the desired portion. The
wellbore 1 may include a casing 6. The wellbore 1 may include a
plurality of locations 10a, 10b, 10c, 20a, 20b, 20c, 30a, 30b, and
30c at which the casing 6 has been perforated and the adjacent
formation 5 has been previously fractured. The wellbore may include
a number of zones A, B, and C each containing a multiple number
locations, such as fracture clusters, through which hydrocarbons
may be produced. The wellbore 1 may be a highly deviated wellbore,
such as a horizontal wellbore, or may be a vertical wellbore. The
wellbore 1 is shown as a horizontal wellbore only for illustrative
purposes.
[0028] A communication line 15 within the tubing string 7 may
connect a sensor 25 positioned within the wellbore 1 to the
surface. The sensor 25 may be a pressure sensor connected to the
exterior of the tubing string 6 between the lower isolator 100A and
the upper isolator 100B. A sensor 35 positioned at the surface may
be used to monitor the production from the wellbore 1. The
isolators 100A and 100B shown in FIG. 3 are isolators 100 having
memory shape elements 150 that may be actuated from a first shape
to a second shape, wherein in the second shape sealing elements on
the exterior of the isolator 100 will engage the casing 6 to
substantially isolate a portion of the wellbore 1. FIG. 3 shows the
isolators 100A and 100B in an unset configuration. Thus, the memory
shape elements 150 are in their respective first shapes.
[0029] FIG. 4 shows the actuation of the memory shape elements 150
of the isolators 100A and 100B being actuated to the second shape
by heating 101 transmitted down the wellbore. The heating 101 may
be hot fluid pumped down the wellbore, the transmission of a
signal, schematically depicted as dashed line 45, that heats up the
memory shape elements 150, and/or the conduction of electricity
down the wellbore 1 to heat up the memory shape elements 150.
Various mechanisms may be used to heat the memory shape elements
150 to a temperature that actuates the elements 150 to move to
their second shapes. The actuation of the memory shape elements 150
causes the lower and upper isolators 100A and 100B to engage the
casing and hydraulically isolate a portion of the wellbore 1. As
shown in FIG. 4, production cluster 10b is hydraulically isolated
from the rest of the wellbore.
[0030] The isolation of a portion of the wellbore 1 may be used to
detect the production being production by the isolated portion of
the wellbore 1. For example, the production from the wellbore 1 may
be measured prior to using the isolators 100A and 100B to
hydraulically isolate a portion of the wellbore 1. The production
from the wellbore may then be measured again after the portion of
the wellbore 1 is hydraulically isolated to detect the amount of
production being produced from the isolated portion. The portion of
the wellbore 1 below the isolated portion of the wellbore may be
produced up the tubing string 7 and the portion of the wellbore 1
above the isolated portion of the wellbore may be produced up the
annulus as indicated by the arrows in FIG. 5. Further, sensor 25
may measure the pressure as well as change in pressure of the
isolated portion of the wellbore 1 which may aid in the
determination of production from the isolated portion of the
wellbore 1. If the production of the specified portion of the
wellbore is inadequate, the portion of the wellbore may be treated,
stimulated, re-stimulated, and/or re-fractured as described herein.
The heating of the shape memory elements 150 may be terminated once
the measuring of a portion of the wellbore is completed. Once the
shape memory elements 150 are cooled to a second temperature the
elements 150 will move back to their respective first shapes
unsetting the isolators 100A and 100B from the casing 1. The
isolators 100A and 100B may then be conveyed to another portion of
the wellbore 1 of interest that may be hydraulically isolated and
monitored.
[0031] In an embodiment, the tubing string 6 may include a port 105
positioned between the lower and upper isolators 100A and 100B as
shown in FIG. 6. The port 105 provides fluid communication with the
exterior of the tubing string 7 and the interior of the tubing
string 7. After a portion of the wellbore 1 has been isolated by
the lower and upper isolators 100A and 100B, the port 105 permits
the monitoring of only the isolated portion of the wellbore 1. The
production from the isolated portion of wellbore 1, such as 10b,
may be produced up the tubing string 7 and monitored as indicated
by the arrows in FIG. 6. If it is determined that the production
from the isolated portion of the wellbore 1 is inadequate, the
tubing string 7 and isolators 100A and 100B may be used to treat
and/or re-facture the portion of the wellbore 1 as shown in FIG. 7.
Fluid is pumped down the tubing string 7 and out the port 105, as
indicated by the arrows in FIG. 7, to treat and/or re-fracture a
portion of the wellbore isolated by the actuated isolators 100A and
100B.
[0032] FIG. 8 shows a flow chart for an embodiment of a method 200
of isolating a portion of a wellbore. The method includes step 210
of positioning an isolator adjacent a first portion of a wellbore.
The isolator may be connected to a tubing string used to convey the
isolator into the wellbore and position the isolator adjacent a
desired portion of a wellbore. The method includes step 220 of
actuating shape memory elements to isolate the first portion of the
wellbore. As discussed herein, the temperature of the shape memory
elements may be increased by various means until a first
temperature is reached, which causes the shape memory elements to
move from a first shape to a second shape. In the second shape, the
shape memory elements may pressure sealing elements against the
wellbore to substantially hydraulically isolate the first portion
of the wellbore.
[0033] In step 230, the production of the isolated portion of the
wellbore is detected. The production from the isolated portion of
the wellbore may be produced and measured through the tubing
string. Alternatively, the production may be measured before and
after to determine the estimated production from the isolated
portion of the wellbore. Pressure readings of the isolated portion
of the wellbore may aid in determining the estimated production of
the first portion of the wellbore. The first portion of the
wellbore may optionally be treated in step 240 and/or the first
portion of the wellbore may optionally be re-fractured in step 250.
The shape memory elements are cooled in step 260 to move the
elements back to the first shape to unset the isolator from the
wellbore. In step 270, the isolator is located at a second portion
of the wellbore to substantially hydraulically isolate the second
zone so that the production of the second portion may also be
detected. Alternatively, the memory shape elements may be
configured so that the elements are cooled to be actuated to a set
position and heated to unset the isolator, if desired.
[0034] FIG. 9 shows a tubing string 7 within a wellbore 1 with a
plurality of isolators 100 positioned along the tubing string 7.
Each isolator includes a lower isolation element 100A and an upper
isolation element 100B, also referred herein as upper and lower
isolators. The tubing string 7 may be used to position the multiple
isolators 100 adjacent a plurality of portions of the wellbore 1
that it may be desired to isolate. The wellbore 1 may include a
casing 6. The wellbore 1 may include a plurality of locations 10a,
10b, 10c, 20a, 20b, 20c, 30a, 30b, and 30c at which the casing 6
has been perforated and the adjacent formation 5 has been
previously fractured. The wellbore 1 may be a highly deviated
wellbore, such as a horizontal wellbore, or may be a vertical
wellbore. The wellbore 1 is shown as a horizontal wellbore only for
illustrative purposes.
[0035] Each of the isolators 100 includes shape memory elements 150
that may be actuated at a first temperature to cause the isolators
100 to engage the casing 6 of the wellbore 1. The shape memory
elements 150 permits more than one isolators to be actuated and
deactivated at once permitting multiple zones to be isolated
simultaneously, if desired.
[0036] Although this disclosure has been described in terms of
certain preferred embodiments, other embodiments that are apparent
to those of ordinary skill in the art, including embodiments that
do not provide all of the features and advantages set forth herein,
are also within the scope of this disclosure. Accordingly, the
scope of the present disclosure is defined only by reference to the
appended claims and equivalents thereof.
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