U.S. patent application number 12/911047 was filed with the patent office on 2011-04-28 for wellbore treatment apparatus and method.
Invention is credited to Gary Smart.
Application Number | 20110094754 12/911047 |
Document ID | / |
Family ID | 41426610 |
Filed Date | 2011-04-28 |
United States Patent
Application |
20110094754 |
Kind Code |
A1 |
Smart; Gary |
April 28, 2011 |
WELLBORE TREATMENT APPARATUS AND METHOD
Abstract
An apparatus for treating a wellbore comprises a downhole
component (22) and a body (16) mounted on the downhole component
(22) to protect the downhole component. The body (16) comprises a
treating agent and at least a portion of the body (16) is
configured to break up to expose the downhole component (22) and
permit release of the treating agent at a downhole location within
a wellbore.
Inventors: |
Smart; Gary; (Alford,
GB) |
Family ID: |
41426610 |
Appl. No.: |
12/911047 |
Filed: |
October 25, 2010 |
Current U.S.
Class: |
166/381 ;
166/205 |
Current CPC
Class: |
E21B 27/02 20130101;
E21B 43/16 20130101 |
Class at
Publication: |
166/381 ;
166/205 |
International
Class: |
E21B 23/00 20060101
E21B023/00; E03B 3/18 20060101 E03B003/18 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 23, 2009 |
GB |
0918617.2 |
Claims
1. An apparatus for treating a wellbore comprising a downhole
component and a body mounted on the downhole component to protect
the downhole component, wherein the body comprises a treating agent
and at least a portion of the body is configured to break up to
expose the downhole component and permit release of the treating
agent at a downhole location within a wellbore.
2. The apparatus according to claim 1, wherein downhole component
comprises a support member.
3. The apparatus according to claim 1, wherein the downhole
component comprises a tubular member.
4. The apparatus according to claim 1, wherein the downhole
component comprises a screen member.
5. The apparatus according to claim 1, wherein the downhole
component comprises a sand screen member.
6. The apparatus according to claim 1, wherein the downhole
component comprises a sensor arrangement.
7. The apparatus according to claim 1, wherein at least a portion
of the body is configured to break up upon exposure to a triggering
condition.
8. The apparatus according to claim 7, wherein the triggering
condition comprises exposure to a downhole fluid.
9. The apparatus according to claim 1, wherein at least a portion
of the body is at least one of degradable, frangible, friable,
dissolvable, wearable, dispersible and diffusible.
10. The apparatus according to claim 1, wherein at least a portion
of the body comprises an elastomer configured to break up to permit
release of the treating agent.
11. The apparatus according to claim 1, wherein the treating agent
is encapsulated within the body.
12. The apparatus according to claim 1, wherein the body comprises
a matrix material, wherein the treating agent is dispersed within
the matrix material.
13. The apparatus according to claim 1, wherein the body comprises
multiple layers, wherein the treating agent is provided in at least
one layer.
14. The apparatus according to claim 1, wherein the body comprises
a first layer comprising the treating agent and a second layer
configured to cover at least a portion of the first layer.
15. The apparatus according to claim 14, wherein the first layer is
at least partially contained within the second layer.
16. The apparatus according to claim 14, wherein at least a portion
of the second layer is configured to be removable from the first
layer to permit release of the treating agent.
17. The apparatus according to claim 14, wherein at least a portion
of the second layer is configured to break up to be removable from
the first layer to permit release of the treating agent.
18. The apparatus according to claim 1, wherein at least a portion
of the treating agent is directly retained within the body.
19. The apparatus according to claim 1, wherein at least a portion
of the treating agent is indirectly retained within the body.
20. The apparatus according to claim 1, wherein the treating agent
is contained within at least one capsule, wherein the at least one
capsule is configured to be released by the body.
21. The apparatus according to claim 1, wherein the treating agent
is configured to at least one of modify a downhole condition, and
stimulate production from a formation or reservoir.
22. The apparatus according to claim 1, wherein the treating agent
is configured to break up a substance.
23. The apparatus according to claim 22, wherein the treating agent
is configured to break up a substance to remove or at least reduce
blockages from one or more downhole flow paths.
24. The apparatus according to claim 1, wherein the treating agent
is configured to break up at least one of filter cake, particulate
material, drill cuttings, rock fragments, organic matter,
precipitates, scale, waxes, asphaltenes, emulsions, colloids, gels
and multiphase fluids.
25. The apparatus according to claim 1, wherein the treating agent
comprises at least one of a breaker agent, surfactant, amphiphilic
compound, acid, phase separator, viscosity modifier, pH modifier
and corrosion inhibitor.
26. The apparatus according to claim 1, wherein the treating agent
is configured to be substantially inactive prior to being released
from the body.
27. The apparatus according to claim 1, wherein the body is mounted
on an outer surface of the downhole component.
28. The apparatus according to claim 1, wherein the downhole
component is configured to form part of a completion assembly.
29. The apparatus according to claim 1, wherein the body is
configured to function as a centraliser.
30. A method of treating a wellbore, comprising: mounting a body on
a downhole component to protect said downhole component, wherein
the body comprises a treating agent; deploying the body and
downhole component into a wellbore; and breaking up at least a
portion of the body to expose the downhole component and permit
release of the treating agent.
31. A downhole apparatus comprising: a downhole component; a body
at least partially surrounding the downhole component, wherein at
least a portion of the body is configured to break up to expose the
downhole component.
32. A downhole method comprising: deploying a downhole component
within a wellbore, wherein the downhole component is at least
partially surrounded by a body; and at least partially breaking up
the body to expose the downhole component.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a wellbore treatment
apparatus and method, and in particular to an apparatus and method
for in-situ treatment of a wellbore with a treating agent.
BACKGROUND TO THE INVENTION
[0002] Wellbores for use in extraction of fluids, such as
hydrocarbons, from a subterranean reservoir or formation are
typically formed by drilling a bore from surface. Drilling is
achieved by use of a drill bit mounted on the end of a drill string
which is advanced into the earth, and a drilling fluid,
conventionally called drilling mud, is pumped through the drill
string and the drill bit. The drilling mud performs a number of
functions, such as lubrication of the drill bit and string, removal
of drill cuttings, wellbore support, containment of formation
fluids and the like. However, under certain conditions, such as
overbalanced drilling, it is known for a fluid portion of the mud
to be driven into the formation, which results in filtrate material
carried by the lost fluid being deposited on the wall of the
drilled bore. This deposited layer is conventionally known as mud
cake or filter cake, and represents a significant restriction to
the production of fluids from the formation.
[0003] Once the wellbore has been drilled to the required depth,
suitable wellbore infrastructure, conventionally called completion
infrastructure is installed within the wellbore and is arranged to
permit controlled production of fluids to surface. Completion
infrastructure, which may include liners, production tubing,
packers, sand screens, valves, flow control devices and the like,
can be very sensitive to the quality of the well, and it is
therefore important that the wellbore is adequately cleaned
following the drilling operation. Cleaning may involve purging the
wellbore of drill cuttings and other solid matter, removal of mud
cake and the like. Chemical agents, such as breaker fluids,
surfactant fluids, acids and the like may also be pumped from
surface into the wellbore for chemical treatment, such as breaking
up emulsions, dissolving solid matter and the like. It has also
been proposed in the art to deliver chemical treating agents into a
wellbore within containers which dissolve to permit release of the
chemical agent. Such proposals are disclosed within, for example,
U.S. Pat. No. 4,611,664, U.S. Pat. No. 4,790,386 and U.S. Pat. No.
2,775,302.
[0004] However, if a poor well clean-up operation is performed this
may result in poor productivity from the well, for example by flow
blockages, damage to completion infrastructure, thick mud cake
deposits and the like. Such poor productivity will require remedial
action, such as performing complex workover or intervention
operations, pumping further chemical agents downhole, or the like,
which may be difficult and expensive to achieve, particularly with
infrastructure which is configured for production operations.
SUMMARY OF THE INVENTION
[0005] According to an aspect of the present invention there is
provided an apparatus for treating a wellbore comprising a body
adapted to be deployed into a wellbore and comprising a treating
agent, wherein the body is configured to permit release of the
treating agent at a downhole location.
[0006] The apparatus may therefore permit a treating agent to be
released at a downhole location within a wellbore. Furthermore, the
apparatus may permit the body to be located at a desired location
within a wellbore, thus providing a more concentrated effect of the
treating agent at the desired location. The apparatus of the
present invention may eliminate or at least mitigate problems
associated with prior art arrangements in which treating agents are
pumped from surface.
[0007] The apparatus may define a downhole apparatus.
[0008] At least a portion of the body may be configured to break up
to permit release of the treating agent. At least a portion of the
body may be configured to break up upon exposure to a triggering
condition. The triggering condition may comprise a natural
condition, such as exposure to a native subterranean fluid,
temperature or the like. The triggering condition may comprise an
artificial condition, such as exposure to artificial heating or
cooling, radiation, electrical current, injected fluids such as
chemicals, mechanical action such as abrasion, erosion, agitation,
crushing or the like. The triggering condition may comprise
exposure to a downhole condition. The downhole condition may
comprise temperature. The downhole condition may comprise pressure.
The downhole condition may comprise a downhole fluid, such as a
hydrocarbon, water, drilling fluid, fracturing fluid or the
like.
[0009] At least a portion of the body may be configured to break up
by one or more of degrading, dissolving, dispersal, diffusion,
erosion, fragmentation or the like. At least a portion of the body
may be at least one of degradable, frangible, friable, dissolvable,
wearable, dispersible, diffusible or the like.
[0010] In one particular embodiment at least a portion of the body
may be configured to degrade upon exposure to a downhole fluid such
as a hydrocarbon fluid.
[0011] At least a portion of the body may comprise an elastomer
configured to break up to permit release of the treating agent. At
least a portion of the body may comprise a degradable elastomer. At
least a portion of the body may comprise one or more of natural
rubber, synthetic rubber, such as EPDM, butyl rubber,
styrene-butadiene rubber and the like.
[0012] The entire body may be configured to break up to release the
treating agent. In this arrangement the body may be sacrificial to
permit release of the treating agent.
[0013] The treating agent may be encapsulated within the body, for
example dispersed within the body.
[0014] The body may comprise a matrix material, wherein the
treating agent is dispersed within the matrix material. The matrix
material may be configured to break-up to permit release of the
treating agent. The matrix material may comprise an elastomer, such
as one or more of natural rubber, synthetic rubber, such as EPDM,
butyl rubber, styrene-butadiene rubber and the like. The matrix
material may be mixed with the treating agent and then formed, for
example by moulding, to produce at least part of the body.
[0015] The body may comprise multiple layers, wherein the treating
agent is provided in at least one layer. The body may comprise a
first layer comprising the treating agent and a second layer
configured to cover at least a portion of the first layer. The
first layer may be wholly or at least partially contained within
the second layer. At least a portion of the second layer may be
configured to be removable from the first layer to permit release
of the treating agent. At least a portion of the second layer may
be configured to be delaminated, de-bonded, separated or the like
from the first layer. At least a portion of the second layer may be
configured to break up to be removable from the first layer.
[0016] The body may comprise a chamber configured to hold the
treating agent, wherein the chamber is configured to be selectively
opened to permit release of the treating agent therefrom. The
chamber may be configured to be selectively opened by break up of
at least a portion of the body.
[0017] The chamber may be configured to be selectively opened by
use of a releasing mechanism. The releasing mechanism may form part
of the apparatus, for example part of the body. The releasing
mechanism may be adapted to be operated upon receipt of a control
signal. The control signal may comprise a wirelessly transmitted
signal, such as an acoustic signal, electromagnetic signal or the
like. The control signal may comprise a wired transmitted signal,
such as an electrical signal, optical signal, pressure signal or
the like. The releasing mechanism may comprise a moveable barrier
member. The moveable barrier member may be moveable to open a port
associated with the chamber. The moveable barrier member may
comprise a valve member, sleeve, plate or the like.
[0018] The treating agent may be directly retained within the
body.
[0019] The treating agent may be indirectly retained within the
body. In one arrangement the treating agent may be contained within
at least one capsule, wherein the at least one capsule may be
configured to be released by the body. In this arrangement the
capsule may be configured to release the treating agent, for
example by time-release, such as by degrading, dissolving or the
like within a downhole environment. At least one capsule may
comprise a container configured to hold the treating agent. At
least one capsule may comprise or be defined by a particle, such as
an elastomer particle, configured to hold the treating agent within
a matrix material within the particle.
[0020] The treating agent may comprise a removable coating, such as
a degradable coating.
[0021] The treating agent may be provided in liquid form, for
example diluted form, concentrated form, or the like. The treating
agent may be provided in solid form, for example in particulate
form, powder, divided form or the like.
[0022] The treating agent may be configured to modify a downhole
condition, such as porosity, for example to at least partially
remedy formation damage.
[0023] The treating agent may be configured to stimulate production
from a formation or reservoir.
[0024] The treating agent may be configured to break up a
substance. The treating agent may be configured to break up a
substance to remove or at least reduce blockages from one or more
downhole flow paths. The one or more downhole flow paths may
comprise formation pores, formation/wellbore interfaces, annulus
areas, wellbore infrastructure flow paths, such as may be provided
in sand screens, gravel packs, inflow control devices, production
tubing or the like. The treating agent may be configured to break
up a substance by, for example, degrading, dissolving, separating,
diluting, concentrating or the like.
[0025] The substance may comprise mud or filter cake. The substance
may comprise particulate material, such as drill cuttings, rock
fragments, organic matter or the like. The substance may comprise
precipitates, such as salt precipitates, scale, waxes, asphaltenes
or the like. The substance may comprise an emulsion, colloid, gel
or the like. The substance may comprise a multiphase fluid, such as
a mixture of oil and water.
[0026] The treating agent may comprise at least one of a breaker
agent, such as an enzymatic breaker agent, surfactant, amphiphilic
compound, acid, phase separator, viscosity modifier, pH modifier or
the like, or any suitable combination thereof.
[0027] The treating agent may comprise a corrosion treating agent,
such as a corrosion inhibitor. In one embodiment the apparatus may
be configured for use in applying the treating agent, which may
comprise a corrosion inhibitor, to perforations within a tubing,
such as a casing tubing. The apparatus may be configured for use
during or subsequent to a perforation operation used to form
perforations within a wellbore. As such, the treating agent may be
released form the body to treat the formed perforations.
[0028] The treating agent may be configured to be substantially
inactive prior to being released from the body.
[0029] The body may be configured to permit a gradual release of
the treating agent. For example, the treating agent may be released
over a time period. The time period may comprise a random time
period. The time period may comprise a predefined time period.
[0030] The body may be configured to permit an intermittent release
of the treating agent.
[0031] The body may be configured to permit a bulk release of the
treating agent. For example, at least a portion, such as a majority
portion of the treating agent may be released from the body
substantially simultaneously.
[0032] The body may be configured to permit automatic release of
the treating agent.
[0033] The body may be configured to permit manual release of the
treating agent, such as upon receipt of an instruction from a
user.
[0034] The apparatus may comprise a support member, wherein the
body is adapted to be mounted on the support member.
[0035] The support member may be configured to be deployed within a
wellbore. In this arrangement the body may be deployed within the
wellbore by the support member.
[0036] The body may be mounted on an outer surface of the support
member. In this arrangement, in use, the body may be positioned
within an annulus formed between a bore wall and the support
member. This may permit release of the treating agent within the
annulus area at a desired location, which is otherwise difficult to
achieve in prior art arrangements.
[0037] The support member may be configured to be permanently
deployed within a wellbore. The support member may be configured to
be installed within a wellbore. The support member may be
configured to form part of a completion assembly.
[0038] The support member may comprise a tubular member such as a
production tubular, casing tubular, liner tubular or the like. The
support member may comprise a screen member, such as sand screen.
The support member may comprise a connector, such as a threaded
connector. The connector may be configured for connecting adjacent
tubulars of a tubing string together.
[0039] The body may be configured to be directly mounted on the
support member. For example, the body may be configured to be
directly secured to the support member, for example by bonding,
interference fitting, screwing, bolting or the like.
[0040] The body may be configured to be indirectly mounted on the
support member. For example, the body may be mounted on a sleeve
and then mounted on the support member. The sleeve may be sealingly
engaged with the support member. The sleeve may permit fluid
communication between the sleeve and the support member.
[0041] The body may be configured to protect a downhole component.
For example, the body may be configured to protect a downhole
component during deployment within a wellbore, during use within a
wellbore or the like. This arrangement may be used in combination
with a body, at least part of which body is configured to break up,
such that break up of the body may expose a portion of the downhole
component, for example to permit use, activation or the like of the
downhole component.
[0042] The downhole component may form part of the apparatus.
[0043] The downhole component may comprise a support member, such
as a sand screen tubular. The downhole component may comprise a
sand screen tubular configured to at least partially support the
body. In this arrangement, break up of the body may permit exposure
of a protected screen region. This may permit protection of at
least a portion of the sand screen tubular, for example from
becoming blocked, plugged or the like from particulate matter,
while the treating agent is being released, following which the
protected screen region may be exposed for appropriate use.
[0044] The downhole component may comprise a sensor arrangement,
such as a sensor cable, sensor head or the like.
[0045] The apparatus may comprise a sensor arrangement. The sensor
arrangement may be configured for use in sensing a condition
associated with at least one of the wellbore, formation and
apparatus. The sensing arrangement may comprise a distributed
sensor arrangement, such as an optical distributed sensor
arrangement. The sensing arrangement may be configured to sense at
least one of pressure, temperature, salinity, phase distribution or
the like. The sensing arrangement may be configured to sense
release, such as complete release, of the treating agent. This may
permit a monitoring or status signal to be communicated to a user,
controller or the like.
[0046] The body may comprise an annular structure. The body may
comprise a strip, block, segment or the like. The body may be
pliable. This may permit the body to be manipulated, shaped or the
like for appropriate use, for example by being wrapped around a
support member.
[0047] The apparatus may comprise a sealing arrangement. The
sealing arrangement may be configured to swell upon exposure to a
swelling activator, such as hydrocarbons, water or the like, or any
suitable combination thereof. The sealing arrangement may be
configured to become exposed to a swelling activator prior to,
during or following release of the treating agent. In one
embodiment the sealing arrangement may be configured to be isolated
from a swelling activator by the body, wherein at least a portion
of the body is configured to break up, for example during release
of the treating agent, to expose the sealing arrangement to a
swelling activator. The sealing arrangement may form part of the
body.
[0048] The body may comprise a gauge mandrel.
[0049] The body may be configured to function as a centraliser. The
body may be configured to function as a centraliser during
deployment of the body within a wellbore. The body may comprise one
or more ribs, which may function as centraliser ribs.
[0050] The apparatus may comprise a single body. The apparatus may
comprise a plurality of bodies, whereat least two of the plurality
of bodies may be configured identically, similarly, differently or
the like.
[0051] According to another aspect of the present invention there
is provided a method of treating a wellbore, comprising:
[0052] deploying a body comprising a treating agent within a
wellbore; and
[0053] releasing the treating agent at a downhole location.
[0054] The method according to the second aspect may be performed
by use of the apparatus according to the first aspect. Features and
uses of the apparatus defined above, directly or indirectly, may be
considered to be optional features of the method according to the
second aspect. For example, the method may comprise breaking up at
least a portion of the body, for example by degrading, to permit
release of the treating agent.
[0055] According to a further aspect of the present invention there
is provided an apparatus for treating a wellbore comprising a body
adapted to be deployed into a wellbore and comprising a treating
agent, wherein at least a portion of the body is configured to
break up to permit release of the treating agent at a downhole
location.
[0056] According to another aspect of the present invention there
is provided a method of treating a wellbore, comprising:
[0057] deploying a body comprising a treating agent within a
wellbore; and
[0058] breaking up at least a portion of the body to release the
treating agent at a downhole location.
[0059] Features and uses of the apparatus defined above, directly
or indirectly, in relation to the first aspect may be considered to
be optional features of the apparatus according to the third aspect
and the method according to the fourth aspect.
[0060] According to a further aspect of the present invention there
is provided a downhole apparatus comprising:
[0061] a downhole component;
[0062] a body at least partially surrounding the downhole
component, wherein at least a portion of the body is configured to
break up to expose the downhole component.
[0063] The downhole component may comprise a sensor
arrangement.
[0064] The downhole component may comprise a sand screen.
[0065] The body may comprise a treating agent configured to be
released upon break up of the body.
[0066] According to another aspect of the present invention there
is provided a downhole method comprising:
[0067] deploying a downhole component within a wellbore, wherein
the downhole component is at least partially surrounded by a
body,
[0068] at least partially breaking up the body to expose the
downhole component.
[0069] Features and uses of the apparatus defined above, directly
or indirectly, in relation to the first aspect may be considered to
be optional features of the apparatus according to the fifth aspect
and the method according to the sixth aspect.
[0070] According to a further aspect of the present invention there
is provided a centraliser comprising a body adapted to be deployed
into a wellbore and comprising a treating agent, wherein the body
is configured to permit release of the treating agent at a downhole
location.
[0071] The body may comprise at least one centralising component,
such as a rib. The centralising component may be separately formed
and subsequently secured to the body. The centraliser component may
be integrally formed with the body.
[0072] Features and uses of the apparatus defined above, directly
or indirectly, in relation to the first aspect may be considered to
be optional features of the centraliser according to the seventh
aspect.
[0073] According to an still further aspect of the present
invention there is provided a downhole apparatus configured to
provide at least one downhole function, wherein the apparatus
comprises a body adapted to be deployed into a wellbore and
includes a treating agent, wherein the body is configured to permit
release of the treating agent at a downhole location.
[0074] Accordingly, the apparatus may be configured to provide at
least one downhole function in addition to permitting treating of a
wellbore.
[0075] The at least one downhole function may comprise centralising
a wellbore member, such as a tubular.
[0076] The at least one downhole function may comprise establishing
a seal, such as a swelling seal. The seal may be provided in the
form of a packer.
[0077] The at least one downhole function may comprise catching a
ball or dart.
[0078] The at least one downhole function may comprise protecting a
downhole component, such as a cable, sensor, sand screen, connector
or the like.
[0079] The at least one downhole function may comprise coupling two
or more downhole components together.
[0080] Another aspect of the present invention relates to n
apparatus for treating a wellbore comprising a downhole component
and a body mounted on the downhole component to protect the
downhole component, wherein the body comprises a treating agent and
at least a portion of the body is configured to break up to expose
the downhole component and permit release of the treating agent at
a downhole location within a wellbore.
[0081] A further aspect of the present invention relates to a
method of treating a wellbore, comprising:
[0082] mounting a body on a downhole component to protect said
downhole component, wherein the body comprises a treating
agent;
[0083] deploying the body and downhole component into a wellbore;
and
[0084] breaking up at least a portion of the body to expose the
downhole component and permit release of the treating agent.
BRIEF DESCRIPTION OF THE DRAWINGS
[0085] These and other aspects of the present invention will now be
described, by way of example only, with reference to the
accompanying drawings, in which:
[0086] FIGS. 1a, 1b and 1c show sequential steps of the use of an
apparatus for treating a wellbore in accordance with an embodiment
of the present invention;
[0087] FIG. 2 shows an apparatus for treating a wellbore configured
in accordance with an embodiment of the present invention;
[0088] FIG. 3 shows an apparatus for treating a wellbore configured
in accordance with an alternative embodiment of the present
invention;
[0089] FIGS. 4a and 4b show sequential steps of the use of an
apparatus for treating a wellbore in accordance with a further
alternative embodiment of the present invention;
[0090] FIGS. 5a and 5b show sequential steps of the use of an
apparatus for treating a wellbore in accordance with a further
alternative embodiment of the present invention;
[0091] FIGS. 6a and 6b show sequential steps of the use of an
apparatus for treating a wellbore in accordance with a further
alternative embodiment of the present invention, wherein the
apparatus defines a centraliser; and
[0092] FIGS. 7 to 9 show alternative arrangements of mounting a
body of an apparatus for treating a wellbore to a support
member.
DETAILED DESCRIPTION OF THE DRAWINGS
[0093] FIGS. 1a, 1b and 1c show sequential steps of the use of an
apparatus, generally identified by reference numeral 10, for
treating a wellbore 12 in accordance with an embodiment of the
present invention. In the embodiment shown the wellbore extends
through a hydrocarbon bearing formation 14.
[0094] Referring initially to FIG. 1a, the apparatus 10 comprises a
pair of bodies 16 which are impregnated with a treating agent,
wherein each body 16 is configured to release the treating agent
in-situ into the wellbore 12 to effect a treating operation
thereof. In the embodiment shown the treating agent comprises a
breaker or surfactant configured to reduce drilling fluid viscosity
and emulsions, and break up solids within the wellbore, such as
drill cuttings 18, filter cake 20 or the like, to thus remove flow
restrictions and permit greater production capacity from the
wellbore 12. It will be recognised, however, that any other
treating agents may be used, such as formation stimulants to
stimulate production of fluids from the formation 14, improve
formation porosity, remediate formation damage or the like.
[0095] Each body 16 is mounted on a support member, which in the
embodiment shown is a slotted sand screen tubular 22 which forms
part of a production tubing string 24. The sand screen 22 is
configured as known in the art, and facilitates production of
formation fluids through the production string 24 while eliminating
particulate matter. In this respect the treating agent within the
apparatus 10 may be configured to remove plugged particles from the
sand screen 22.
[0096] A pair of axially spaced packers 26, 28 are configured to
form a seal between a wall of the wellbore 12 and the production
tubing string 24 to establish an isolated annular production zone
30, within which the apparatus 10 is located. The packers 26, 28,
which may be provided by swelling packers, mechanical packers,
inflatable packers or the like, are configured to prevent migration
of fluids along the annulus outside the isolated zone 30. It should
be noted that a relatively short isolated annular zone 30 is
illustrated. However, this is for clarity only and it will be
recognised that a longer zone may be provided.
[0097] The apparatus 10 is deployed on the production tubing string
24 from surface until the required wellbore depth is reached,
following which the packers 26, 28 are set. Once located at the
required depth, or even while still being deployed towards the
required depth, the treating agent may be released from the bodies
16, as shown in FIG. 1b. In this respect each body 16 is formed
from a degradable matrix material, specifically a degradable
rubber, which is impregnated with the treating agent. The rubber
matrix material in the embodiment shown is configured to degrade
upon exposure to a downhole fluid, such as hydrocarbon fluid,
drilling fluid or the like. In other embodiments the rubber matrix
material may be configured to degrade upon exposure to particular
temperatures ranges, pressures or the like. Accordingly, once the
bodies 16 begin to degrade within the wellbore 12, as shown in FIG.
1b, the treating agent will be released into the isolated zone 30,
as demonstrated by arrows 32, to break up or reduce emulsions,
particulate matter 18 and filter cake 20.
[0098] Once the bodies 16 have completely degraded, as shown in
FIG. 1c, fresh regions 34 of the sand screen tubular 22 will become
exposed. In this respect regions 34 may be protected from plugging
and the like prior to and during release of the treating agent, and
subsequently be exposed following treatment. This arrangement may
therefore provide a degree of flow assurance associated with the
sand screen 22 and tubing string 24.
[0099] Although the apparatus 10 shown in FIG. 1 includes a pair of
bodies 16 formed by a degradable matrix impregnated with the
treating agent, other arrangements are possible within the scope of
the invention, some of which are shown in FIGS. 2 to 4.
[0100] Referring initially to FIG. 2, a wellbore treatment
apparatus, generally identified by reference numeral 110 includes a
body 116 which comprises an outer layer 140 which defines an inner
chamber containing a treating agent 142. The treating agent 142 may
be provided as a layer of the body 116. The outer layer 142
comprises a degradable material, such as a degradable rubber, which
is configured to degrade upon exposure to a triggering condition,
such as contact with hydrocarbons, to permit release of the
treating agent 142.
[0101] FIG. 3 shows a wellbore treatment apparatus, generally
identified by reference numeral 210, which includes a body 216
having an outer casing 244 which defines an inner chamber
containing a treating agent 242. The outer casing 244 includes a
port 246 which is selectively opened by a sleeve 248. In FIG. 2 the
upper half of the apparatus 110 is illustrated with the sleeve 246
in a closed configuration, and the lower half of the apparatus 210
is illustrated in an open configuration, permitting release of the
treating agent 242 as demonstrated by arrow 250. The sleeve 248 is
configured to be actuated to open the port 246 upon receipt of a
control signal, which in the embodiment shown comprises an acoustic
control signal 252.
[0102] FIG. 4 illustrates a further embodiment of a wellbore
treatment apparatus, in this case generally represented by
reference numeral 310. As shown in FIG. 4a, the apparatus 310
comprises a body 316 which is formed of an outer layer 354 which
encapsulates an inner layer of swellable material 356, such as
swellable rubber. The swellable material 356 is configured to swell
upon exposure to a swelling activator, such as a downhole fluid,
for example hydrocarbons. Accordingly, the outer layer 354 may
function to isolate the swellable material 256 from exposure to a
swelling activator. This may prevent the swelling rubber from
swelling prematurely, for example while the apparatus 310 is being
deployed into a wellbore.
[0103] The outer layer 354 is formed of a degradable matrix
material which is impregnated with a treating agent, wherein the
matrix material is configured to degrade upon exposure to a
suitable triggering condition, such as exposure to a downhole
fluid, for example hydrocarbons, thus releasing the treating agent.
Accordingly, when in situ in a wellbore the outer layer 354 will
degrade, thus exposing the swellable material 356 to a swelling
activator to cause swelling, as illustrated in FIG. 4b. The
swellable material 356 in the embodiment shown may be configured to
function as a packer. For example, the swellable material 356 may
be configured to function as one or both packers 26, 28 shown in
FIG. 1.
[0104] As described above in relation to FIG. 1, a sand screen
tubular 22 may be afforded a degree of protection from the body 16
prior to and during release of the treating agent. However, in
other arrangements such a configuration may be used to afford
protection to other downhole components. Such an exemplary
alternative arrangement is shown in FIG. 5, reference to which is
now made.
[0105] FIG. 5a illustrates a wellbore treatment apparatus, in this
case generally identified by reference numeral 410. Apparatus 410
is similar to apparatus 10 shown in FIG. 1, and as such like
features share like reference numerals, incremented by 400.
Accordingly, the apparatus 410 includes a body 416 which degrades
to release a treating agent for treating a wellbore 412, wherein
the body 416 is mounted on a support member in the form of a sand
screen tubular 422. In other arrangements, however, the body 416
may be mounted on any other support member, such as a solid
tubular, connector or the like.
[0106] The body 416 is configured to encapsulate a sensing
arrangement 458, wherein the sensing arrangement 458 is exposed
when the body 416 is completely degraded, as shown in FIG. 5b.
Accordingly, the body 416 may provide a degree of protection to the
sensing arrangement 458, for example when the apparatus 410 and
sensing arrangement 458 are being deployed into the wellbore
412.
[0107] The sensing arrangement 458 may be configured to sense one
or more conditions within the wellbore, such as temperature,
pressure or the like. The sensing arrangement 458 may comprise one
or more point sensors, distributed sensors or the like, and may be
associated with a sensor cable 460, which may be configured for
distributed sensing, transmitting signals associated with the
sensor arrangement 548, or the like.
[0108] The sensing arrangement 458 may additionally, or
alternatively, be configured to sense the condition of the body
416, and thus the release of the treating agent. For example, the
sensing arrangement 458 may be configured to sense the degree or
rate of degrading of the body 416.
[0109] Reference is now made to FIGS. 6a and 6b in which there is
shown a further alternative embodiment of the present invention. In
this case a wellbore treating apparatus, generally identified by
reference numeral 510, includes a body 516 mounted on a support
tubular 522. The body 516 is provided in the form of a centraliser
and includes a number of ribs 562. In use, the centraliser is
configured to centralise the support tubular 522 and associated
infrastructure within a wellbore 512, for example to minimise
friction contact, stick-slip and the like during deployment.
Additionally, the centraliser may provide protection to the support
tubular 522 when being deployed within the wellbore, and may also
provide protection to cables, conduits or the like, such as cable
564. The body 516 comprises a degradable matrix material which is
impregnated with a treating agent, such that when the matrix
material degrades, for example upon contact with a downhole fluid,
the treating agent is released, as demonstrated by arrows 566 in
FIG. 6b.
[0110] Although the entire body 516 is shown to be degradable in
FIG. 6, this is not essential. For example, the ribs may be formed
of a non-degradable material, such as a tough or durable material
which will resist damage and the like during contact with a wall of
the wellbore 512 or other downhole infrastructure.
[0111] In the embodiments shown above, arrangements are described
which include a body mounted on a support member. Many
configurations of mounting the body on the support member fall
within the scope of the invention. For example, as shown in FIG. 7
an apparatus 610 may be configured in which a body 616 is directly
mounted on a support member 622, for example by bonding, clamping,
screwing, riveting, interference fitting or the like.
[0112] Alternatively, as shown in FIG. 8 an apparatus 710 may be
configured in which a body 716 is mounted on a sleeve 770, for
example by bonding, wherein the sleeve 770 is mounted on a support
member 722. In this embodiment the sleeve 770 may form part of the
body 716. As shown in FIG. 8, the sleeve 770 is fully engaged with
the outer surface of the support member 722. A sealing arrangement
(not shown) may be provided between the sleeve 770 and the support
member 722.
[0113] FIG. 9 shows a further alternative embodiment of a wellbore
treating apparatus, identified by reference numeral 810. In a
similar manner to that shown in FIG. 8, the apparatus 810 includes
a body 816 mounted on a sleeve 870 which is in turn mounted on a
support member 822. However, in this embodiment the sleeve 870 is
mounted on the support member 822 to define a flow path 872
therebetween. This flow path may be used to assist circulation of
the treating agent or the like.
[0114] The present invention may advantageously permit in situ
treatment of a wellbore, without requiring delivery, for example by
pumping, of a treating fluid from surface level, complex
intervention operations or the like. Furthermore, in embodiments
where a treating agent is released as a result of break up or
degrading of part of the apparatus, this provides advantages in
eliminating any particular tool or carrier assembly from being
permanently installed within a wellbore, which may be
undesirable.
[0115] It should be understood that the embodiments described
herein are merely exemplary and that various modifications may be
made thereto without departing from the scope of protection. For
example, the body may be provided in any suitable form, including
the illustrated annular form, for example in the form of a strip,
block, segment or the like. Additionally, in embodiments where the
body is degradable, only a portion may be degradable. For example,
a portion of the body may be non-degradable. Furthermore, although
embodiments have been described in which the body, or portions of
the body are degradable, this may also include other mechanisms
which permit break up of the body, such as dissolving, fragmenting,
eroding, diffusing or the like. Additionally, any number of bodies
may be provided with a wellbore treating apparatus. Further, the
apparatus ay comprise a component which is configured to degrade or
break up upon exposure to any suitable triggering condition, such
as temperature, pressure, downhole fluid or the like.
* * * * *