U.S. patent application number 12/106765 was filed with the patent office on 2009-10-22 for system and method to facilitate treatement and sand control in a wellbore.
Invention is credited to Bradley P. Malone.
Application Number | 20090260814 12/106765 |
Document ID | / |
Family ID | 41200147 |
Filed Date | 2009-10-22 |
United States Patent
Application |
20090260814 |
Kind Code |
A1 |
Malone; Bradley P. |
October 22, 2009 |
System and Method to Facilitate Treatement and Sand Control in a
Wellbore
Abstract
A technique provides a multi-stage well treatment system having
a plurality of packers and a plurality of flow valves. The
multi-stage well treatment system can be moved downhole in a
wellbore and actuated to isolate a plurality of sections along the
wellbore for treatment. The system and methodology enable
treatment, e.g. fracturing, of select sections via the flow valves,
while also enabling use of the flow valves to establish a
permeable, stabilized pack surrounding each flow valve.
Inventors: |
Malone; Bradley P.;
(Manhattan, KS) |
Correspondence
Address: |
SCHLUMBERGER TECHNOLOGY CORPORATION;David Cate
IP DEPT., WELL STIMULATION, 110 SCHLUMBERGER DRIVE, MD1
SUGAR LAND
TX
77478
US
|
Family ID: |
41200147 |
Appl. No.: |
12/106765 |
Filed: |
April 21, 2008 |
Current U.S.
Class: |
166/276 ;
166/51 |
Current CPC
Class: |
E21B 43/02 20130101 |
Class at
Publication: |
166/276 ;
166/51 |
International
Class: |
E21B 43/02 20060101
E21B043/02 |
Claims
1. A well system, comprising: a tubular structure deployed in a
wellbore; a plurality of packers mounted on the tubular structure
and positioned for actuation in an annulus surrounding the tubular
structure to divide the wellbore into isolated sections; a
plurality of flow valves arranged on the tubular structure to
provide at least one flow valve in each isolated section to control
flow between an interior of the tubular structure and the annulus,
wherein the flow valves comprise a ball seat; and a stabilized
filter pack disposed in the annulus at each isolated section, the
stabilized filter pack being formed of a resin coated sand.
2. The well system as recited in claim 1, wherein the plurality of
flow valves comprises a plurality of sliding sleeves.
3. The well system as recited in claim 1, wherein the resin coated
sand is disposed in each isolated section between the flow valve
and a surrounding casing having a perforated region positioned to
allow fluid communication between the annulus and a surrounding
formation.
4. The well system as recited in claim 1, wherein the resin coated
sand is placed at or below fracturing pressure.
5. The well system as recited in claim 1, wherein each flow valve
comprises a ball seat.
6. The well system as recited in claim 1, wherein each flow valve
can be selectively closed to block flow between the annulus and an
interior of the tubular structure.
7. The well system as recited in claim 1, wherein the plurality of
packers comprises open hole packers.
8. A method to improve production from a well, comprising: forming
a tubular structure with a plurality of packers and a plurality of
flow valves, the plurality of packers creating sections for
isolation along the tubular structure, the plurality of flow valves
being placed such that at least one flow valve is in each section
between adjacent packers, and wherein the flow valves comprise a
ball seat; deploying the tubular structure in a wellbore; isolating
the sections along an annulus surrounding the tubular structure;
performing a fracturing procedure at each section by delivering a
fracturing fluid down through the tubular structure and out through
a flow valve at each section; and using the plurality of flow
valves to deliver a proppant to each section to form a permeable,
stabilized pack that performs sand control.
9. The method as recited in claim 8, wherein isolating comprises
actuating a plurality of packers.
10. The method as recited in claim 9, wherein actuating comprises
actuating the packers against a well casing having perforations in
each section.
11. The method as recited in claim 8, wherein using comprises
filling the annulus in each section with the permeable, stabilized
pack until the permeable, stabilized pack fills the space between
the flow valve in each section and a surrounding casing having a
perforated region.
12. The method as recited in claim 8, wherein using comprises
creating the permeable, stabilized pack with resin coated sand.
13. The method as recited in claim 8, further comprising flowing a
production fluid from a surrounding formation, through the
permeable, stabilized pack, and into the tubular structure through
the flow valve in at least some of the sections.
14. The method as recited in claim 8, further comprising
selectively closing selected flow valves.
15. A well system, comprising: a well string having a multi-stage
fracturing system deployed in a wellbore to fracture a plurality of
sections along the wellbore, the multi-stage fracturing system
having packers that can be actuated to isolate the plurality of
sections and flow valves disposed between the packers, and wherein
the flow valves comprise a ball seat; and a permeable, stabilized
pack disposed in each of the plurality of sections via the flow
valves.
16. The well system as recited in claim 15, wherein the permeable,
stabilized pack comprises resin coated sand.
17. The well system as recited in claim 15, wherein each flow valve
may be individually shifted between open and closed positions.
18. The well system as recited in claim 17, wherein each flow valve
comprises a sliding sleeve.
19. A method, comprising: constructing a multi-stage fracturing
system having packers and flow valves disposed between the packers
to create a plurality of sections, and wherein the flow valves
comprise a ball seat; deploying the multi-stage fracturing system
in a wellbore; actuating the packers to isolate the plurality of
sections; and using the flow valves to deliver a fracturing fluid
to each section and to deliver a proppant to each section for
forming a permeable, stabilized pack in an annulus at each
section.
20. The method as recited in claim 19, further comprising
sequentially fracturing each section.
21. The method as recited in claim 19, further comprising producing
a fluid at each section by flowing a production fluid from a
surrounding formation, through the permeable, stabilized pack, and
into the multi-stage fracturing system.
22. The method as recited in claim 19, wherein using comprises
forming the permeable, stabilized pack from resin coated sand.
Description
BACKGROUND
[0001] Fracturing operations are conducted in a well to improve the
flow of production fluid from a surrounding formation into a
wellbore. A variety of fracturing techniques can be employed and
involve pumping a fracturing fluid downhole and into the
surrounding formation to ultimately improve the flow of production
fluids through the formation and into the wellbore. If sand control
is required, a separate sand control completion is deployed in the
wellbore in an additional procedure to facilitate removal of
particulates from produced fluid.
SUMMARY
[0002] In general, the present invention provides a multi-stage
well treatment system having a plurality of packers and a plurality
of flow valves. The multi-stage well treatment system can be moved
downhole in a wellbore and actuated to isolate a plurality of
sections along the wellbore for treatment. The system and
methodology enable treatment, e.g. fracturing, of select sections
via the flow valves. However, the flow valves also are used to
establish a permeable, stabilized pack surrounding each flow valve
in the annulus of each section.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] Certain embodiments of the invention will hereafter be
described with reference to the accompanying drawings, wherein like
reference numerals denote like elements, and:
[0004] FIG. 1 is a schematic front elevation view of a multi-stage
well system deployed in a wellbore, according to an embodiment of
the present invention;
[0005] FIG. 2 is a schematic illustration of one example of the
multi-stage well system in which permeable, stabilized packs have
been formed in a plurality of isolated sections of the wellbore,
according to an embodiment of the present invention;
[0006] FIG. 3 is a flowchart illustrating a procedure for using the
multi-stage well system, according to an embodiment of the present
invention; and
[0007] FIG. 4 is a flowchart illustrating another aspect of using
the multi-stage well system, according to an embodiment of the
present invention.
DETAILED DESCRIPTION
[0008] 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.
[0009] The present invention generally relates to a system and
method for facilitating well treatments, e.g. fracturing
treatments, and for placing permeable, stabilized packs at a
plurality of isolated sections along the wellbore. Generally, a
multi-stage well system is run into a wellbore and actuated to
isolate a plurality of sections along the wellbore. The multi-stage
well system comprises flow valves arranged so that at least one
flow valve is in each isolated section. The flow valves are used to
inject treatment fluid, e.g. fracturing fluid, into each of the
sections. However, the flow valves also can be used to direct a
proppant into the annulus at each section. The proppant is used to
form a stabilized filter pack in each section which functions as a
sand control tool.
[0010] The multi-stage well system uses a series of isolation
devices, e.g. packers, deployed along a tubular structure to form a
wellbore completion able to isolate the wellbore sections. The
packers can be used in either cased hole or open hole completions
to divide the well into manageable sections. These manageable
sections enable stimulation, and later production, that is specific
to intervals bounded by pairs of packers. The flow valves enable
well treatments, e.g. fracturing treatments, and also facilitate
creation of the permeable, stabilized packs in the isolated
wellbore sections. Generally, each wellbore section has a flow
valve positioned along the tubular structure towards the top of the
section so that flow through the isolation valve is generally at
the upper end of each isolated section when the well system is
actuated in a wellbore. During production, production fluids flow
from the surrounding formation and through the stabilized pack
before entering the completion through the flow valve in each
isolated wellbore section.
[0011] The multi-stage well system can be used to carry out a
variety of well treatment procedures in many types of wells,
including vertical wells and deviated wells, e.g. horizontal wells.
The well system also can be utilized in many types of well
environments, including high-temperature environments,
high-pressure environments, H.sub.2S environments, and CO.sub.2
environments. The treatment and production operations can be
carried out in sandstone, carbonate, shale, coal or other types of
formations.
[0012] Referring generally to FIG. 1, one embodiment of a
multi-stage well system 20 is illustrated as deployed in a wellbore
22. The well system 20 is designed to carry out well treatment
procedures and sand control to facilitate production. As
illustrated, multi-stage well system 20 comprises a treatment
system 24 that enables multi-stage treatment procedures. The
treatment procedures may be followed by production of fluid through
a plurality of isolated wellbore sections as production fluid flows
from a surrounding formation 26.
[0013] In the embodiment illustrated, multi-stage treatment system
24 is formed as part of a single tubing string/completion 30
deployed in wellbore 22 via a conveyance 32, such as tubing. In the
example provided, well system 20 is deployed into a generally
vertical well extending down from a surface rig 36 or other
deployment equipment positioned at a surface location 38. However,
well system 20 also can be deployed into deviated wellbores, such
as horizontal wellbores.
[0014] Multi-stage treatment system 24 comprises a plurality of
isolation devices 40, e.g. packers, which can be actuated to
isolate sections 42 along wellbore 22. The multi-stage treatment
system 24 further comprises a plurality of flow valves 44 with at
least one flow valve 44 disposed in each section 42 between
adjacent packers 40. Generally, the flow valve 44 in each wellbore
section 42 is positioned in the upper portion of the section 42
between adjacent packers 40. The flow valves 44 can be used to
direct/inject treatment fluid into each isolated well section 42
during a treatment procedure. For example, flow valves 44 can be
used to direct a fracturing fluid into the surrounding formation 26
at each well section 42 to fracture the desired formation zones,
thereby promoting the flow of production fluids to wellbore 22. In
many applications, the treatment procedure is conducted at
individual well sections 42 and progresses from one well section 42
to the next. In a specific application, the multi-stage treatment
system 24 is used to conduct a well stimulation procedure by
placing the flow valves 44 between external packers 40 at multiple
well sections 42. The packers 40 function to divide the well into
manageable sections that enable stimulation and production specific
to the interval bounded by packers at each end of that
interval/well section. Examples of stimulation procedures include
matrix stimulation, acid fracturing stimulation, and propped
fracturing stimulation.
[0015] Upon completion of the treatment procedure, production fluid
can be flowed from the various regions of formation 26 into
completion 30 via flow valves 44. As described in greater detail
below, the inflow of production fluid is filtered by a stabilized
filter pack disposed in the wellbore annulus surrounding completion
30 at each wellbore section 42 formed between adjacent packers 40.
In the embodiment illustrated, packers 40 and flow valves 44 are
mounted on a tubular structure 46. The tubular structure 46 can be
used to conduct treatment fluids to flow valve 44 and also to
receive production fluids, e.g. oil, through the flow valves
44.
[0016] In FIG. 1, packers 40 have been deployed into wellbore 22
and are ready for actuation against the surrounding wellbore wall
48. Depending on the specific application, wellbore wall 48 may be
an open wellbore wall or a casing in a cased wellbore. In an open
wellbore, packers 40 comprise open hole wellbore packers that can
be set against an uncased wellbore. However, packers 40 also can be
selected for actuation against a wellbore casing. In the latter
example, perforations are formed through the wellbore casing at
each isolated wellbore section 42 to enable flow between the
formation 26 and wellbore 22.
[0017] Referring to FIG. 2, one embodiment of well system 20 is
illustrated in greater detail. As illustrated, the packers 40 have
been actuated and expanded against wellbore wall 48 to isolate well
sections 42. In this embodiment, each flow valve 44 comprises a
sliding sleeve 50 that can be actuated between at least an open and
a closed position. The sliding sleeves 50 can be moved by a variety
of mechanisms, including balls or darts dropped downhole through
completion 30 or by shifting tools delivered downhole on an
appropriate conveyance. In embodiments that utilize balls to
actuate the sliding sleeve, each sliding sleeve comprises a ball
seat 52 that works in cooperation with the sliding sleeve 50 to
close off flow. The sliding sleeve 50 can be actuated to block flow
of fluid from tubing string 30 to the surrounding formation 26
within specific well sections 42. The balls also can be used to
block flow along tubing string 30 between isolated well sections
42. In some embodiments, the ball seats 52 have different diameters
from one flow valve 44 to the next to enable sequential closing of
the flow valves 44 as each sequential well section 42 is treated.
It should be noted, however, that other types of valves or
mechanisms can be used to control the flow of treatment fluid
through the tubing string and into each well section 42.
[0018] In the example illustrated in FIG. 2, the flow valves 44
also are used to deliver proppant into the isolated sections 42.
For example, the proppant can be delivered into a plurality of
annular regions 54 disposed between the tubular structure 46 and
the surrounding wellbore wall 48 in isolated well sections 42. The
proppant is delivered to form permeable, but stabilized packs 56
that function to perform sand control with respect to fluids
flowing in from the surrounding formation 26. The proppant can be
delivered downhole via a service tool 58, such as a conduit that
can be moved along the interior of completion 30 to selectively
deliver proppant to desired flow valves 44. The proppant is
delivered from tool 58, through the appropriate flow valve 44, and
into the surrounding annular region 54 to form the permeable,
stabilized pack 56 in the desired, isolated well section 42. By way
of example, the permeable, stabilized packs 56 can be formed from
resin coated sand 60. In many applications, the resin coated sand
is placed in each section 42 at or below fracturing pressure.
[0019] Accordingly, multi-stage well system 24 can be used for well
treatment, e.g. delivery of acid or fracturing fluid, and also for
sand control. Certain treatment procedures can be combined or
sequential. The well system 24 further provides a quick method to
place multizone, permeable, stabilized packs that also have the
ability to be easily isolated in the future if an undesirable
production profile develops. For example, select wellbore sections
42 can be isolated simply by closing the appropriate flow valve
44.
[0020] Once well system 20 is deployed in wellbore 22, the
permeable, stabilized packs 56 can be formed in some or all of the
annular regions 54. The stabilized packs 56 can be formed in an
open hole or a cased hole. In the embodiment illustrated in FIG. 2,
for example, the wellbore 22 is cased with a wellbore casing 62
having perforated regions 64 through which fluid is communicated
between formation 26 and wellbore 22 during injection or production
of fluids. In each isolated section 42, the flow valve 44 is
generally located at the top of the isolated section, and the
perforated regions 64 are generally located at a bottom end of the
isolated section to allow the stabilized pack 56 to better remove
particulates as fluid flows through a substantial portion of the
stabilized pack.
[0021] The well system 20 can be used in a variety of well
treatment and production applications. In one application example,
the treatment string/completion 30 is initially deployed in
wellbore 22, as illustrated by block 66 in the flowchart of FIG. 3.
Once deployed to a desired location in the wellbore, well sections
are isolated along wellbore 22 via packers 40, as illustrated by
block 68. At this stage of the process, an initial treatment
procedure can be carried out, as illustrated by block 70. The
treatment procedure may comprise injecting an acid or a fracturing
fluid at each well section 42 via the flow valve 44 located in that
specific well section. Additionally, a packing procedure can be
carried out in which the permeable, stabilized packs 56 are formed
in each well section 42, as illustrated by block 72. In some
applications, the fracturing and packing procedures may be
combined. The stabilized packs 56 may be formed from resin coated
sand delivered to the desired flow valves 44 and isolated sections
42 via service tool 58.
[0022] After completing the desired well treatment and the
deposition of permeable, stabilized packs 56, a desired formation
fluid can be flowed into wellbore 22 and into tubing string 30
through stabilized packs 56, as illustrated by block 74. The
stabilized packs 56 filter the inflowing fluid, thus removing
particulates from the fluid. After flowing through stabilized packs
56, the formation fluid moves into completion 30 through the
appropriate flow valve or flow valves 44 in each isolated section
42. Over time, if one or more of the isolated sections 42 begin
producing in an undesirable manner, flow through that particular
stabilized pack 56 and isolated section 42 can be reduced or
blocked. For example, the flow valve 44 in each isolated section 42
can be used to restrict or close off flow through that section as
desired to improve overall production, as illustrated by block 76.
Undesirable production in one or more of the well sections 42 may
result from the production of gas, water or other undesirable
fluids at some point during the life of the well.
[0023] Depending on the environment and the completions used to
produce fluids from formation 30, the procedures for
stimulation/treatment and production can be adjusted. In FIG. 4,
another example of a procedure for treating a well and controlling
sand during production from the well is illustrated in flowchart
form. In this example, the well is initially prepared, as
illustrated by block 78. Preparation of the well may involve
drilling the well, casing the well, removing an old completion from
an existing well, reducing the amount of completion skin to provide
each interval/section with an opportunity to be produced to its
full capacity, or conducting other procedures designed to
facilitate well treatment and production. The well may be prepared,
for example, in sand bodies of multiple low-pressure, weak
formations. The well also may be prepared in mature fields that are
intended for production from multiple zones via an artificial lift
mechanism, such as a high rate electric submersible pumping
system.
[0024] Once the wellbore is prepared, perforations 66 are formed in
each of the well sections 42, as illustrated by block 80. The
perforations 66 also can result from re-perforation by forming, for
example, oriented gravel pack perforations into the plane of
fracture. Subsequently, additional preparatory procedures may be
conducted to prepare the wellbore for receipt of well system 20, as
illustrated by block 82. For example, when well sections are thin
or open hole completions are utilized, an optional procedure may be
employed to squeeze well intervals with resin to consolidate the
formation. Pressure tests are then performed on the intervals
subjected to resin consolidation.
[0025] Following any additional preparatory procedures, the
multi-stage well system 20 is run in hole, as illustrated by block
84, and the packers 40 are set to isolate well sections 42. A
treatment procedure can then be performed in each isolated well
section 42, as illustrated by block 86. By way of example, the
treatment procedure may comprise sequentially performing an
acidizing or fracturing procedure at each of the isolated well
zones 42. The well sections 42 are then filled with, for example,
resin coated sand to establish the permeable, stabilized packs 56,
as illustrated by block 88. The resin coated sand is allowed to
reach a required minimum strength, and a final well clean out can
be conducted, as illustrated by block 90.
[0026] A final completion is then run downhole, as illustrated by
block 92. The final completion may comprise a variety of production
related completions, including completions designed for
artificially lifting production fluids to a desired collection
location. For example, an electric submersible pumping system can
be delivered downhole to pump the fluids that collect within the
well system 20. With the final completion in place, the well can be
placed on production to deliver production fluids to the desired
collection location, as illustrated by block 94. During production,
the flow valves 44 can be used to reduce or stop fluid flow through
well sections 42 that experience undesirable water cut or gas
influx.
[0027] As described above, well system 20 can be constructed in a
variety of configurations for use in many environments and
applications. Additionally, the size and arrangement of the
components can be adjusted according to the environment and
according to treatment or production parameters. A variety of
packers or other isolation devices can be used in both open hole
and cased hole applications. Also, various types of flow valves 44
can be used to direct proppant and various treatment fluids
outwardly or to conduct the inward flow of production fluids.
Furthermore, the permeable, stabilized packs 56 can be formed with
a variety of proppants, additives and materials capable of readily
forming multiple permeable, stabilized packs.
[0028] 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.
* * * * *