EP2459841A2

EP2459841A2 - Measurement apparatus

Info

Publication number: EP2459841A2
Application number: EP10731780A
Authority: EP
Inventors: Daniel Watley; Graeme Mcrobb
Original assignee: Swellfix BV
Current assignee: Swellfix BV
Priority date: 2009-07-31
Filing date: 2010-06-22
Publication date: 2012-06-06
Also published as: GB0913293D0; CA2769171A1; WO2011012838A3; WO2011012838A2

Abstract

A downhole measurement apparatus comprises a seal body (20) configurable from a non- sealing configuration to a sealing configuration to isolate a downhole region, wherein the seal body (20) is configured to permit communication between a measurement device (26) and the isolated region. In one embodiment the seal body (20) defines a port (30) configured to permit communication, such as fluid communication, between the measurement device (26) and the isolated region. The seal body may comprise a swellable material and the port support may comprise a telescopic tubular support (44)..

Description

MEASUREMENT APPARATUS

FIELD OF THE INVENTION

The present invention relates to a measurement apparatus, and in particular to a downhole measurement apparatus for use in measuring properties of a subterranean formation and/or a wellbore.

BACKGROUND TO THE INVENTION

In the oil and gas exploration and production industry, wellbores are drilled into the earth to intercept subterranean hydrocarbon bearing formations or reservoirs to permit the hydrocarbons to be produced to surface. The conditions within the wellbore and formation can have a significant influence on many aspects associated with the well, such as well infrastructure, production rates and the like. Accordingly, it is extremely desirable to perform a number of measurements associated with the wellbore, and even the formation, to identify particular in situ conditions. Such measurements may include pressure, temperature, vibration, chemical composition, or the like. These measurements may simply be used for monitoring purposes, improving reservoir management, and/or may be used to assist in identifying a requirement to take appropriate intervention or remedial action to ensure desired well conditions, such as production rates, can be achieved and maintained. Furthermore, appropriate measurements may provide information relating to the effectiveness, or otherwise, of any remedial action taken.

It is known in the art to take measurements from within a production well which is, or is intended to, produce hydrocarbons. A variety of measurement or logging techniques are known in this regard. For example, in some cases well activity may be ceased to permit a workover or intervention operation to be performed to take the necessary measurements, for example by deploying logging equipment into the well on wireline, followed by appropriate analysis and then any appropriate remedial action. However, ceasing well activity, especially production, is not desired due to the associated loss/delay of production. To resolve this is it known in the art to install permanent downhole gauges within a wellbore which are used to permit permanent monitoring to be achieved.

In many cases it may be desirable to take measurements from particular zones or regions within a wellbore and/or an associated formation. This typically requires isolation of the zone of interest such that the effects from adjacent zones can be minimised. One conventional approach to achieve this is to use a pair of axially spaced packers mounted on a tubing string, wherein once activated the packers create a seal between the tubing string and the wall of a bore. This results in an isolated annular region being defined axially between the packers, and laterally between the tubing string and the bore wall. A sensor or gauge mandrel is typically located between the packers within the isolated annulus to take the necessary measurements. However, this approach involves the deployment and activation of a number of separate components, and the resulting measurements are limited to conditions within the isolated annular region, which may not be entirely representative of the formation conditions. Also, the sensor or gauge mandrel will be exposed to contact with the wellbore while being deployed to the desired depth, such that damage of the sensor and measurement equipment may occur.

It is also known in the art to create an observation well within the vicinity of a production well, with the assumption that the conditions within the observation well and surrounding formation will be similar to that of the production well. This approach to measurement may reduce the complexities associated with measuring or logging within a production well which contains a significant amount of completion infrastructure and the like.

In the oil and gas industry it is desirable to know the relative quantities, or saturation, of oil and water within a formation. This may be achieved by performing carbon/oxygen logging, in which a radioactive based tool using gamma ray spectroscopy detects the carbon atoms in oil, and the oxygen atom in water, wherein the ratio of the two can provide an indication of reservoir saturation. This type of tool may be used within downhole tubulars to assess a surrounding formation. However, to obtain sufficient and accurate results it is important to ensure that there are no voids behind the tubing. This typically requires the tubing to be cemented in place, which in some applications may not be desirable, and it is often the case that cementing does not sufficiently fill all voids. Further, cracks and fractures are known to form within cement which may adversely affect any logging results.

US 2007/0151724 discloses a system and method for isolating a wellbore region, wherein a swellable sealing layer is configured to swell to seal an annulus between a completion and a bore wall. The sealing layer incorporates a probe, such as an electrode, on an outer surface thereof such that swelling of the layer brings the probe into contact with the bore wall. The probe may be used in taking appropriate measurements at the location of the seal.

SUMMARY OF THE INVENTION

According to a first aspect of the present invention there is provided a downhole measurement apparatus comprising a seal body configured to isolate a downhole region, wherein the seal body is adapted to permit communication between a measurement device and an isolated region.

In use, the measurement apparatus may be located at a desired downhole location and the seal body configured to isolate a downhole region, wherein measurement of at least one property of the isolated region may be achieved by communication with a measurement device via the seal body. The seal body may therefore function to both isolate a downhole region and permit a measurement device to communicate with said isolated region to measure properties thereof. This arrangement may permit the measurement device to measure one or more properties precisely at the location of the isolated region. The measurement device may be configured to measure at least one downhole property. The at least one downhole property may comprise pressure, temperature, chemical composition, conductivity, water saturation, interface properties, such as properties of an oil/water interface, carbon composition, oxygen composition, salinity, flow or the like.

The measurement device may be provided separately of the measurement apparatus. Alternatively, the measurement apparatus may comprise a measurement device.

The measurement device may be provided remotely from the seal body. In this arrangement at least one conduit or the like may be provided between the seal body and the measurement device.

The measurement device may be configured to be deployed separately of the seal body. In one embodiment the measurement device may be deployed on wireline, slickline, coiled tubing, a tubing string or the like.

The measurement device may be positioned adjacent the seal body. In one arrangement the measurement device may be at least partially surrounded by the seal body. This may permit the seal body to provide protection to the measurement device, for example protection against engagement with a downhole surface or object, such as a wall surface of a wellbore during deployment.

The seal body may define a port configured to permit communication between an isolated region and the measurement device. The seal body may comprise a port support arrangement, such as a tubular port support arrangement. This may permit the port to remain open, for example during activation or the like of the seal body. The port support arrangement may comprise a telescopic tubular support.

The seal body may be configurable from a non-sealing configuration to a sealing configuration. The seal body may be expandable to be configured between a non-sealing configuration and a sealing configuration. The seal body may be radially expandable. The seal body may be reconfigurable between non-sealing and sealing configurations.

The seal body may comprise an engagement surface configured to engage a downhole surface, such as a wall surface of a drilled bore. The engagement surface of the seal body may define an isolated region when engaged with a downhole surface. In one embodiment, the entire engagement surface of the seal body may define a downhole isolated region. The engagement surface may be configured to engage and isolate a region of a wall of a drilled bore. This may permit a measurement device to communicate with the isolated region of the bore wall defined by the engagement surface of the seal body. In some embodiments, the drilled bore may extend through a subterranean formation. In such an embodiment, permitting the measurement device to communicate with an isolated region of a bore wall may permit measurements of at least one property of the formation to be taken, determined, inferred or the like.

The seal body may define a generally curved engagement surface. The engagement surface may define a substantially cylindrical surface, such as a part cylindrical surface, completely cylindrical surface or the like.

The seal body may be generally cylindrical or part cylindrical. The seal body may be generally annular or part annular.

The seal body may be mounted on a support member. The support member may be provided separately of the measurement apparatus.

Alternatively, the measurement apparatus may comprise a support body configured to support the seal body. The support member may comprise a tubular member. The support member may be configured to be mounted on a tubing string, such as a liner tubing string, casing string, drilling string, production string, coiled tubing or the like. The support member may be configured to be integrated within a tubing string. For example, the support member may be configured to be threadably coupled within an axial length of a tubing string. The support member may be configured to be mounted on a surface of a tubing string. For example, the support member may define a sleeve adapted to be mounted on a tubing string. This arrangement may permit increased flexibility of location of the support member. This may also facilitate easier transportation of the measurement apparatus.

The support member may be configured for use in deploying the measurement apparatus to a required downhole location. For example, the support member may be secured to a tubing string which is deployed downhole. The support member may define a mandrel.

The support member may be configured to support a measurement device.

The seal body may be mechanically actuated to establish a seal. For example, the seal body may be actuated by mechanical compression, mechanical slips or the like.

The seal body may be inflatable.

The seal body may comprise a swellable material configured to swell upon exposure to a swelling activator. The swellable material may be adapted to be activated by a chemical activator, thermodynamic activator, fluid dynamic activator, or the like, or any suitable combination thereof. For example, the swellable material may be adapted to be activated by a fluid, such as water, hydrocarbons, cement, drilling mud, or the like, or any suitable combination thereof. The swellable materia) may be selected to swell upon exposure to fluids or conditions present in a target downhole environment. The swellable medium may be adapted to be activated by heat, pressure, radioactivity or the like.

The swellable materia! may comprise an elastomer, such as rubber or the like.

The measurement device may comprise one or more sensors, such as pressure sensors, temperature sensors or the like. The measurement device may comprise one or more distributed sensors, such as fibre optic distributed sensors, for example distributed temperature sensors, distributed pressure sensors.

The measurement device may comprise a sensor configured to function by communicating radioactivity through the seal body towards an isolated region. Such a sensor may be configured for operation by gamma ray spectroscopy, such as in a carbon/oxygen sensor. The use of a seal body, such as a swellable seal body in combination with this type of radioactive based sensor is particularly advantageous in that voids between the sensor and a region of interest may be eliminated by the seal body, permitting sufficient operation of the sensor.

The measurement apparatus may be configured to accommodate a cable associated with a measurement device. The cable may be configured to communicate signals to and/or from the measurement device. The cable may comprise an electrical conductor, optical conductor, hydraulic conduit or the like.

The seal body may be configured to accommodate a cable, conduit or the like. For example, the seal body may be configured to accommodate the passage of a cable or conduit therethrough, for example to extend towards a further measurement apparatus.

The measurement apparatus of the present invention may be configured for use with one or more sealing assemblies, such as packer assemblies, for example swellable packer assemblies. The measurement apparatus may be configured to be positioned between a pair of axially separated sealing assemblies. The packer assemblies may be sleeve mounted.

The measurement apparatus may be configured for use with at least one further measurement apparatus. The at least one further measurement apparatus may be provided in accordance with the first aspect. In this arrangement a single cable or conduit or the like may extend through or between the measurement apparatuses. The apparatus may be configured for use in a wellbore associated with an hydrocarbon bearing formation, water bearing formation or the like. The apparatus may be configured for use in an exploration wellbore, production wellbore, injection wellbore, observation wellbore or the like.

According to a second aspect of the present invention there is provided a method of downhole measurement, comprising:

deploying a measurement apparatus downhole to a desired location;

activating a sealing body of the measurement apparatus to isolate a downhole region; and

providing communication between the isolated region and a measurement device via the seal body.

The measurement apparatus may be provided in accordance with the first aspect. It should be understood that features associated with the first aspect, and their identified and implied use or uses may apply to the method according to the second aspect.

According to a third aspect of the present invention there is provided a downhole sealing assembly comprising a seal body configured to isolate a downhole region, wherein the seal body is adapted to permit communication between a measurement device and an isolated region.

The assembly according to the third aspect may comprise features associated with the apparatus of the first aspect.

According to a fourth aspect of the present invention there is provided a downhole measurement apparatus comprising:

a seal body configured to seal a void and define a downhole isolated region; and

a measurement device configured to measure a property of an isolated region, wherein the seal body permits communication between the isolated region and the measurement device.

According to a fifth aspect of the present invention there is provided a measurement assembly comprising a plurality of measurement apparatus according to the first aspect.

The plurality of measurement apparatus may be arranged axially.

One or more packers may be positioned between adjacent measurement apparatus.

According to a sixth aspect of the present invention there is provided a measurement apparatus comprising:

a seal body configured to seal a void in a downhole region; and

a radioactive measurement device configured to emit radioactivity across the sealed void to measure a property of a downhole region.

The seal body may comprise a swellable material.

BRIEF DESCRIPTION OF THE DRAWINGS

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:

Figure 1A is a diagrammatic representation of a measurement apparatus in accordance with an embodiment of the present invention, wherein the apparatus is shown in a first configuration;

Figure 1B is a diagrammatic representation of the measurement apparatus of Figure 1A, shown in a second configuration;

Figures 2 and 3 a diagrammatic representations of support arrangements for a port provided in the apparatus of Figure 1 ;

Figure 4 is a diagrammatic representation of multiple measurement assemblies provided in a string; and Figure 5 is a diagrammatic representation of a string of measurement assemblies provided in combination with packers.

DETAILED DESCRIPTION OF THE DRAWINGS

A measurement apparatus, generally identified by reference numeral 10, in accordance with an embodiment of the present invention is shown in Figure 1. The apparatus 10 is shown in Figure 1A being deployed into a wellbore 12, and in Figure 1B the apparatus 10 is shown in a configuration where a downhole region 14 from which measurements are to be taken is isolated. The wellbore 12 may be associated with a hydrocarbon bearing formation. The wellbore 12 may be a production wellbore, observation wellbore, exploration wellbore, injection wellbore or the like.

The apparatus 10 comprises a support member in the form of a mandrel 16 which is installed within a tubing string 18, such as a liner tubing string. Accordingly, the apparatus 10 may be deployed to the required wellbore depth by the tubing string 18. The mandrel 16 supports a seal body 20 which comprises a swellable material configured to swell upon exposure to a swelling activator, such as a wellbore fluid, for example oil or water. The seal body 20 is annular and completely extends around the mandrel 16. The seal body 20 is shown in Figure 1A in an unswollen^• configuration, and in Figure 1B in a swollen configuration where an engagement surface 22 of the seal body has engaged the wall 24 of the bore 12 to isolate region 14.

A measurement device 26 is also supported by the mandrel 16, wherein the measurement device 26 is surrounded by the seal body 20. Thus, the seal body 16 may provide protection for the measurement device 26, for example during deployment into the wellbore 12. In the embodiment shown the measurement device 26 is configured to measure temperature and pressure. Further, in the embodiment shown the measurement device 26 comprises a carbon/oxygen sensor arrangement 28 which uses gamma ray spectroscopy to detect carbon atoms in oil and oxygen atoms in water, with the ratio between the two providing an indication of saturation at the downhole isolated region 14.

A cable 34 extends from the measurement device 26, for example to surface level. The cable 34 may comprise an electrical cable, fibre optic cable or the like. A cable head 35 is associated with the measurement device to permit connection with the cable 34.

The seal body 20 defines a port 30 which in use permits communication between the isolated region and the measurement device 26. The port 30 remains open to permit communication when the seal body 20 is expanded, as shown in Figure 1B. Accordingly, once region 14 has been isolated by expansion of the seal body 20, properties of the region 14, which may reflect properties of a subterranean formation 32 through which the wellbore 12 extends, can be measured by the measurement device 26, via the port 30 in the seal body 20. Also, the sensor arrangement 28 may communicate directly through the seal body 20, wherein the seal body 20 eliminates any voids between the sensor 28 and the formation 32, which voids are otherwise known to provide erroneous measurements or results.

As noted above, the port 30 is configured to remain open after the seal body 20 has expanded. This may be achieved in a number of ways. An exemplary arrangement is shown in Figure 2, reference to which is now made. In Figure 2A the seal body 20 is shown in a non-swollen configuration, and in Figure 2B in a swollen or expanded configuration. A tubular body 40 is located within the port 30, wherein the tubular body comprises a splayed upper end 42, which upper end 42 is generally aligned with the upper surface, or engagement surface 22, of the seal body 20. Upon expansion of the seal body 20 the upper portion 42 of the tubular body 40 is deformed to become aligned with the port 30, to thus maintain the port 30 open.

Figures 3A and 3B shows an alternative arrangement in which a telescopic tubular member 44 is provided, which extends upon expansion of the seal body 20, as demonstrated in Figure 3B. A number of measurement apparatus 10 according to the present invention may be installed in a single tubing string, as shown in Figure 4. This arrangement may permit multiple isolated regions along the length of a wellbore 12 to be established and subsequently measured. In the example shown in Figure 4, a cable 34 extends between the individual apparatus 10. In embodiments using an electrical cable, the cable may comprise individual Y-junctions or splitters to permit individual cable heads 25 to be secured to the cable 34. In other embodiments, such as where optical cable is used, the cable may extend directly through the measurement device, from one end to the other.

An alternative arrangement is shown in Figure 5, reference to which is now made. In this arrangement a plurality of measurement apparatus 110 are mounted, via sleeves, on a tubing string 118 which extends into a wellbore 12. Each measurement apparatus 110 is similar to apparatus 10 first shown in Figure 1, and as such like components share like reference numerals, incremented by 100. Accordingly, each measurement apparatus 110 comprises a support member 116 which supports a seal body 120, wherein the seal body 120 defines a port 130 permitting communication with a measurement device (not shown) surrounded or covered by the seal body 120. The seal body 120 may be annular, as shown in Figure 1. However, and as represented in Figure 5, the seal body 120 is discrete and only covers a portion of the support body 116.

A pair of sleeve mounted packers 50, which may be swellable packers, are located on either axial side of each apparatus 110, such that the packers may be activated to isolate the region within which each apparatus 110 is located. The functionality of each apparatus 110 is similar to that described above and as such no further description will be given.

The use of sleeve mounted apparatus and packers permits increased flexibility of design, creation and instalment of the tubing string. Also, by providing the apparatus and/or the packers as sleeve mounted will facilitate easier transportation of these components.

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 the invention. For example, the measurement device may be configured to measure any desired property associated with the region of interest, and even associated with other regions. The measurement device may comprise any suitable form of measurement device or sensor, and may include a distributed temperature sensor, distributed pressure sensor or the like. Additionally, the length of the seal body may be conveniently selected, altered or the like to establish the desired isolated region. Furthermore, the apparatus may be configured to communicate wirelessly, such that the use of any cables and the like may be eliminated. Also, in the embodiments shown the measurement device is shown adjacent to, and covered by the seal body. However, in alternative arrangements the measurement device may me located remotely from the seal body, and communication provided via a conduit or the like.

Additionally, in the embodiment first shown in Figure 1 , a carbon/oxygen sensor arrangement is provided with the measurement device. However, this is only for illustration purposes only. In other embodiments the carbon/oxygen sensor may be omitted. Alternatively, the carbon/oxygen sensor may be the only sensor within the apparatus. Alternatively further, the carbon/oxygen sensor may be deployed as a separate component, such as a point sensor, for example deployed on wireline or the like.

Furthermore, the seal body may be arranged to permit communication between the measurement device and any other isolated region, and is not limited to an isolated region defined by a surface of a wellbore. For example, the seal body may provide communication with an annular region, such as may be defined between a tubular and a wall of a wellbore.

Claims

CLAIMS:

1. A downhole measurement apparatus comprising a seal body configurable from a non-sealing configuration to a sealing configuration to isolate a downhole region, wherein the seal body is configured to permit communication between a measurement device and the isolated region.

2. The apparatus according to claim 1 , wherein the seal body defines at least one port configured to permit communication between a measurement device and the isolated region.

3. The apparatus according to claim 2, comprising a port support arrangement configured to permit the port to remain open during activation of the seal body.

4. The apparatus according to claim 3, wherein the port support arrangement comprises a tubular support.

5. The apparatus according to claim 3 or 4, wherein the port support arrangement comprises a telescopic tubular support.

6. The apparatus according to any preceding claim, wherein the measurement device is located internally of an outer surface of the seal body.

7. The apparatus according to any preceding claim, wherein the seal body is configured to provide fluid communication between the isolated region and the measurement device.

8. The apparatus according to any preceding claim, wherein the seal body is adapted to engage a downhole surface to isolate said surface and permit communication with said isolated surface.

9. The apparatus according to any preceding claim, wherein the seal body comprises an engagement surface configured to engage a downhole surface and define an isolated region when engaged with a downhole surface.

10. The apparatus according to any preceding claim, wherein the seal body is expandable to be configured between a non-sealing configuration and a sealing configuration.

11. The apparatus according to any preceding claim, wherein the seal body is configured to be at least one of mechanically actuated and inflated to be configured between a non-sealing configuration and a sealing configuration.

12. The apparatus according to any preceding claim, wherein the seal body comprises a swellable material configured to swell upon exposure to a swelling activator to be configured between a non-sealing configuration and a sealing configuration.

13. The apparatus according to any preceding claim, comprising a measurement device configured to communicate with the isolated region via the seal.

14. The apparatus^" according to any preceding claim, wherein the measurement device is configured to measure at least one of temperature and pressure.

15. The apparatus according to any preceding claim, wherein the measurement device is provided remotely from the seal body.

16. The apparatus according to any one of claims 1 to 14, wherein the measurement device is at least partially surrounded by the seal body.

17. The apparatus according to any preceding claim, comprising a support member configured to support the seal body.

18. The apparatus according to claim 17, wherein the support member is configured to be mounted on a tubing string.

19. The apparatus according to claim 17 or 18, wherein the support member defines a mandrel.

20. The apparatus according to claim 17, 18 or 19, wherein the support member is configured to support a measurement device.

21. The apparatus according to any preceding claim, wherein the measurement device comprises one or more sensors.

22. The apparatus according to any preceding claim, wherein the measurement device comprises one or more optical based sensors.

23. The apparatus according to any preceding claim, wherein the measurement device comprises one or more distributed sensors.

24. The apparatus according to any preceding claim, wherein the measurement device comprises a sensor configured to function by communicating radioactivity through the seal body towards an isolated region.

25. The apparatus according to any preceding claim, wherein the measurement device comprises a sensor configured for operation by gamma ray spectroscopy.

26. The apparatus according to any preceding claim, configured to accommodate a cable associated with a measurement device.

27. The apparatus according to claim 26, wherein the cable comprises at least one of an electrical conductor, optical conductor and fluid conduit.

28. The apparatus according to any preceding claim, configured to accommodate the passage of a cable or conduit therethrough to extend towards a further measurement apparatus.

29. The apparatus according to any preceding claim, configured for use with one or more packer assemblies.

30. The apparatus according to any preceding claim, configured to be positioned between a pair of axially separated packer assemblies.

31. The apparatus according to any preceding claim, wherein the seal body is annular.

32. The apparatus according to any preceding claim, wherein the seal body is mounted on a support member, and extends partially around a surface of said support member.

33. A method of downhole measurement, comprising:

deploying a measurement apparatus downhole to a desired location;

providing communication between the isolated region and a measurement device via a port formed in the seal body.