Patent Application
20110094754
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.
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.
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.
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.
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.
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.
The apparatus may define a downhole apparatus.
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.
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.
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.
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.
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.
The treating agent may be encapsulated within the body, for example dispersed within the body.
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.
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.
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.
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.
The treating agent may be directly retained within the body.
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.
The treating agent may comprise a removable coating, such as a degradable coating.
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.
The treating agent may be configured to modify a downhole condition, such as porosity, for example to at least partially remedy formation damage.
The treating agent may be configured to stimulate production from a formation or reservoir.
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.
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.
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.
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.
The treating agent may be configured to be substantially inactive prior to being released from the body.
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.
The body may be configured to permit an intermittent release of the treating agent.
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.
The body may be configured to permit automatic release of the treating agent.
The body may be configured to permit manual release of the treating agent, such as upon receipt of an instruction from a user.
The apparatus may comprise a support member, wherein the body is adapted to be mounted on the support member.
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.
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.
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.
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.
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.
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.
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.
The downhole component may form part of the apparatus.
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.
The downhole component may comprise a sensor arrangement, such as a sensor cable, sensor head or the like.
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.
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.
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.
The body may comprise a gauge mandrel.
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.
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.
According to another aspect of the present invention there is provided a method of treating a wellbore, comprising:
deploying a body comprising a treating agent within a wellbore; and
releasing the treating agent at a downhole location.
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.
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.
According to another aspect of the present invention there is provided a method of treating a wellbore, comprising:
deploying a body comprising a treating agent within a wellbore; and
breaking up at least a portion of the body to release the treating agent at a downhole location.
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.
According to a further aspect of the present invention there is provided 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.
The downhole component may comprise a sensor arrangement.
The downhole component may comprise a sand screen.
The body may comprise a treating agent configured to be released upon break up of the body.
According to another aspect of the present invention there is provided a downhole method comprising:
deploying a downhole component within a wellbore, wherein the downhole component is at least partially surrounded by a body,
at least partially breaking up the body to expose the downhole component.
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.
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.
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.
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.
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.
Accordingly, the apparatus may be configured to provide at least one downhole function in addition to permitting treating of a wellbore.
The at least one downhole function may comprise centralising a wellbore member, such as a tubular.
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.
The at least one downhole function may comprise catching a ball or dart.
The at least one downhole function may comprise protecting a downhole component, such as a cable, sensor, sand screen, connector or the like.
The at least one downhole function may comprise coupling two or more downhole components together.
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.
A further aspect of the present invention relates to 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.
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:
a, 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;
a 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;
a 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;
a 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
a, 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.
Referring initially to
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.
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.
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
Once the bodies 16 have completely degraded, as shown in
Although the apparatus 10 shown in
Referring initially to
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
As described above in relation to
a illustrates a wellbore treatment apparatus, in this case generally identified by reference numeral 410. Apparatus 410 is similar to apparatus 10 shown in
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
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.
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.
Reference is now made to
Although the entire body 516 is shown to be degradable in
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
Alternatively, as shown in
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.
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.
| Number | Date | Country | Kind |
|---|---|---|---|
| 0918617.2 | Oct 2009 | GB | national |
