PACKER ELEMENT

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This Application claims priority to, and therefore claims benefit under 35 U.S.C.

§ 119(e), U.S. Provisional Application 61/379,582 filed on September 2, 2010. This provisional patent application is incorporated by reference in its entirety.

BACKGROUND

[0002] Hydrocarbon fluids such as oil and natural gas are obtained from a subterranean geologic formation, referred to as a reservoir, by drilling a well that penetrates the hydrocarbon-bearing formation. Once a wellbore has been drilled, the well must be completed before hydrocarbons can be produced from the well. A completion involves the design, selection, and installation of equipment and materials in or around the wellbore for conveying, pumping, or controlling the production or injection of fluids. After the well has been completed, production of oil and gas can begin.

[0003] Sealing systems, such as packers or anchors, are commonly deployed in a well as completion equipment. Packers are often used to isolate portions of a wellbore from one another. For example, packers are used to seal the annulus between a tubing string and a wall or casing of the wellbore, isolating the portion of the wellbore above the packer from the portion of the wellbore below the packer. Packers can be actuated by hydraulic pressure transmitted either through the tubing bore, annulus, or a control line. Other packers can be actuated via an electric line deployed from the surface of the wellbore. This necessitates deployment of actuating instrumentation and complicates the development of completions systems and associated reliability issues and operating costs (rig time etc.) with packer operations. Furthermore, packers have been used that employ elements that respond to the surrounding well fluids and swell to form a seal. Swellable packers can swell from an unexpanded state to an expanded state, thereby creating a seal, when the swellable material comes into contact with a triggering fluid.

[0004] However, in hostile environments, such as high pressure, high temperature

(HPHT) environments, as well as sour environments, the dimensions and characteristics of a swellable packer may change. Further, the characteristics of the swellable packer may continue to change even after the swellable packer is removed from a hostile environment. Accordingly, there exists a need for an apparatus and method that allows for in-situ, visual measurement of characteristics of a swellable packer during, and after, the swellable packer is exposed to a sour, HPHT environment.

SUMMARY OF INVENTION

[0005] This summary is provided to introduce a selection of concepts that are further described below in the detailed description. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter.

[0006] According to one aspect, there is provided a measurement apparatus including a housing having at least one aperture formed therein, a swellable packer element disposed within the housing, and at least one biasing element disposed within the housing and coupled between the housing and the swellable packer element, in which the aperture is configured to enable observation of the swellable packer element, and in which the housing is configured to receive a trigger fluid therein.

[0007] According to another aspect, there is provided a method of measurement including measuring a characteristic of a swellable packer element disposed within a housing, the housing having at least one aperture formed therein, introducing a trigger fluid into the housing and into the swellable packer element, observing the swellable packer element through the at least one aperture of the housing, and re-measuring the characteristic of the swellable packer element through the at least one aperture.

BRIEF DESCRIPTION OF DRAWINGS

[0008] Figure 1 is a schematic view of a visual pressure-volume-temperature cell system, in accordance with embodiments disclosed herein.

[0009] Figure 2 is a cross-sectional view of a measurement apparatus, in accordance with embodiments disclosed herein. [0010] Figure 3 is a cross-sectional schematic view of a swellable packer element disposed within a housing of a measurement apparatus, in accordance with embodiments disclosed herein.

[0011] Figure 4 is a cross-sectional schematic view of a measurement apparatus having a first sampling port and a second sampling port, in accordance with embodiments disclosed herein.

[0012] Figure 5 is a flow chart of a measurement process, in accordance with embodiments disclosed herein.

DETAILED DESCRIPTION

[0013] The following is directed to various embodiments of the disclosure. Although one or more of these embodiments may be preferred, the embodiments disclosed should not be interpreted, or otherwise used, as limiting the scope of the disclosure, including the claims. In addition, those having ordinary skill in the art will appreciate that the following description has broad application, and the discussion of any embodiment is meant only to be exemplary of that embodiment, and not intended to suggest that the scope of the disclosure, including the claims, is limited to that embodiment.

[0014] Certain terms are used throughout the following description and claims refer to particular features or components. As those having ordinary skill in the art will appreciate, different persons may refer to the same feature or component by different names. This document does not intend to distinguish between components or features that differ in name but not function. The figures are not necessarily to scale. Certain features and components herein may be shown exaggerated in scale or in somewhat schematic form and some details of conventional elements may not be shown in interest of clarity and conciseness.

[0015] In the following discussion and in the claims, the terms "including" and

"comprising" are used in an open-ended fashion, and thus should be interpreted to mean "including, but not limited to ... " Also, the term "couple" or "couples" is intended to mean either an indirect or direct connection, mechanical, hydraulic, pneumatic, electrical, or otherwise. Thus, if a first component is coupled to a second component, that connection may be through a direct connection, or through an indirect connection via other components, devices, and connections. Further, the terms "axial" and "axially" generally mean along or substantially parallel to a central or longitudinal axis, while the terms "radial" and "radially" generally mean perpendicular to a central, longitudinal axis.

[0016] As used herein, the terms "above" and "below"; "up" and "down"; "upper" and

"lower"; "upwardly" and "downwardly"; and other like terms indicating relative positions above or below a given point or element are used in this description to more clearly describe some embodiments. However, when applied to equipment and methods for use in wells that are deviated or horizontal, such terms may refer to a left to right, right to left, or diagonal relationship, as appropriate.

[0017] Referring to Figure 1 a schematic view of a test system 100 having a visual pressure-volume-temperature (PVT) cell 101, according to embodiments disclosed herein, is shown. The test system 100 may include the PVT cell 101, one or more fluid reservoirs 112 and 113, a pump 120, and a pressure gauge 121. In one or more embodiments, the one or more fluid reservoirs 112 and 113 may be pistoned cylinders. Additionally, in one or more embodiments, the pump 120 may be a variable volume displacement pump.

[0018] Further, as shown, the visual PVT cell 101 includes a housing 105, the housing

105 having an inner tube 106 and an outer shell 107. In one or more embodiments, the inner tube 106 may be transparent, and may be a PYREX tube, in which the inner tube

106 may be formed from PYREX. In one or more embodiments, the outer shell 107 may be a steel shell having one or more vertical, tempered glass plates disposed therein to allow visual observation of contents within the inner tube 106. For example, in one or more embodiments, at least one aperture, or slot, may be formed in the outer shell 107 of the housing 105.

[0019] As will be discussed below, the one or more tempered glass plates may be disposed within the outer shell 107, e.g. , within the at least one aperture, and the at least one aperture may be configured to enable, or allow, observation of a testing sample (not shown) disposed within the housing 105. Further, in one or more embodiments, a floating piston 114 may be mounted within the inner tube 106, which may allow for mercury- free operation. Furthermore, as shown, an impeller mixer 115 may be coupled to an end, e.g. , a bottom end, of the housing 105. In one or more embodiments, the impeller mixer 115 may be a magnetically coupled impeller mixer and may be configured to mix contents received within the housing therein.

[0020] In one or more embodiments, the volume, and consequently the pressure, of the fluids under investigation, e.g., test fluids (gas or liquid) contained within the housing 105, may be controlled by the variable volume displacement pump 120, which may allow for the injection and/or the removal of fluids contained within the fluid reservoirs 112 and 113, as well as the fluids contained in the housing 105. In one or more embodiments, the fluids contained within the fluid reservoirs 112 and 113 and the housing 105 may include transparent hydraulic fluid. Transparency of the fluid contained in the fluid reservoirs 112 and 113 and the housing 105 may improve visibility, i.e., observation, of a testing sample contained within the housing. However, those having ordinary skill in the art will appreciate that the fluids contained within the fluid reservoirs 112 and 113 and the housing 105 are not limited to transparent fluids.

[0021] In one or more embodiments, the same fluids may be introduced, or displaced, into a gap formed between the outer steel shell 107 and the inner tube 106, to maintain a balanced, e.g., minimal, differential pressure on the inner tube 106. Equilibration of the fluids under investigation may be achieved through the use of the impeller mixer 115. As discussed, above, the impeller mixer 115 may be coupled to a bottom end of the housing 105. In one or more embodiments, the housing 105 may include a first end cap 108 and a second end cap 109. As shown, the impeller mixer 115 is coupled to the second end cap 109, which is disposed near the bottom end of the housing 105.

[0022] In one or more embodiments, each of the first end cap 108 and the second end cap

109 may help shield the contents within the housing 105 from magnetic effects/flux and may also provide for introducing test fluid into the housing 105 and sampling test fluid from within the housing 105. Further, in one or more embodiments, a first sampling port

110 may be disposed on the first end cap 108, above the floating cylinder 114, and a second sampling port 111 may be disposed on the second end cap 109, near the impeller mixer 115. Each of the first sampling port 110 and the second sampling port 111 may be used as an entry port to introduce fluid, e.g., a trigger fluid, into the housing 105, to induce swelling of a swellable packer element (not shown). [0023] Volumes within the test system 100 may be determined by measuring a height of the piston 114 and phase interfaces of test fluids within the PVT cell 101. The inner tube 106, which contains a testing sample, may be calibrated prior to the experiment to determine a calibration factor, e.g., a cross-sectional area of the testing sample, cm (cm /cm). The calibration factor may then be used to translate a height measurement of the testing sample into a volume measurement. In one or more embodiments, the measurement device may be a digital camera with a measurement resolution of 10 μιη (or 0.01 cm ³ ).

[0024] In one or more embodiments, the vapor phase of the test fluid may be withdrawn from the system via the first sampling port 110, and the liquid phase of the test fluid may be sampled through the second sampling port 111. The PVT cell 101 may be housed within a temperature controlled, forced-air circulation oven. A temperature of the PVT cell 101 may be measured with a platinum resistance temperature detector (RTD) and may be displayed on a digital indicator with an accuracy of 0.2°F or 0.1°C. The pressure of the PVT cell 101 may be monitored with a calibrated, digital pressure gauge accurate to ± 0.1 % of full scale. Further, a light source 122 may be used to provide increased vision, to assist with measuring the height of the piston 114 and phase interfaces of test fluids within the PVT cell 101. Those having ordinary skill in the art will appreciate that fluids may include both gases and/or liquids. Further, those having ordinary skill in the art will appreciate that the height measurement of the testing sample may be visually made without the use of a digital camera, or similar means, and that the temperature measurement of the PVT cell 101 may be measured by any means known in the art.

[0025] Referring to Figure 2, a cross-sectional view of a measurement apparatus 201, according to embodiments disclosed herein, is shown. The measurement apparatus 201 may include a housing 205 having at least one aperture 225, or slot, formed therein, a swellable packer element 204 disposed within the housing 205, and at least one biasing element, e.g., biasing elements 202 and 203, coupled between the housing 205 and the swellable packer element 204. In one or more embodiments, the aperture 225 may be configured to enable, or allow, observation of the swellable packer element 204 disposed within the housing 205. In other words, the aperture 225 may allow the swellable packer element 204, which is disposed within the housing 205, to be viewed or observed from outside of the housing 205. Further, in one or more embodiments, the housing 205 may be configured to receive a trigger fluid therein. As used herein, the term "swellable packer element" may be a complete, i.e., entire, swellable packer element or a material sample for a swellable packer element.

[0026] The swellable packer elements 204 may be made by, or formed from, any swellable material. Illustrative swellable materials may be or include ethylene- propylene-copolymer rubber hydrocarbon oil, ethylene-propylene-diene terpolymer rubber hydrocarbon oil, butyl rubber hydrocarbon oil, halogenated butyl rubber hydrocarbon oil, brominated butyl rubber hydrocarbon oil, chlorinated butyl rubber hydrocarbon oil, chlorinated polyethylene hydrocarbon oil, starch-polyacrylate acid graft copolymer water, polyvinyl alcohol cyclic acid anhydride graft copolymer water, isobutylene maleic anhydride water, acrylic acid type polymers water, vinylacetate- acrylate copolymer water, polyethylene oxide polymers water, carboxymethyl celluclose type polymers water, starch-polyacrylonitrile graft copolymers water, highly swelling clay minerals (i.e. sodium bentonite) water, styrene butadiene hydrocarbon, ethylene propylene monomer rubber hydrocarbon, natural rubber hydrocarbon, ethylene propylene diene monomer rubber hydrocarbon, ethylene vinyl acetate rubber hydrocarbon, hydrogenised acrylonitrile-butadiene rubber hydrocarbon, acrylonitrile butadiene rubber hydrocarbon, isoprene rubber hydrocarbon, chloroprene rubber hydrocarbon, and/or polynorbornene hydrocarbon.

[0027] Still referring to Figure 2, one or more embodiments of the housing 205 of the measurement apparatus 201 may include an inner tubing 206 and an outer shell 207. In one or more embodiments, the inner tubing 206 may include PYREX glass. In other words, in one or more embodiments, the inner tubing 206 may be formed from PYREX glass. However, those having ordinary skill in the art will appreciate that the inner tubing 206 may be formed from materials other than PYREX glass. For example, the inner tubing 206 may be formed from any substantially rigid, material known in the art that may also be transparent.

[0028] In one or more embodiments, the outer shell 207 may include a nickel corrosion- resistant material. In other words, in one or more embodiments, the outer shell 207 may be formed from a nickel corrosion-resistant material. Those having ordinary skill in the art will appreciate that the outer shell 207 may be formed from materials other than nickel corrosion-resistant material. For example, the outer shell 207 may be from any substantially rigid material known in the art, such as steel. Further, in one or more embodiments, the at least one aperture 225 may be formed in the outer shell 207. In one or more embodiments, a glass plate (not shown) may be disposed within the outer shell 207.

[0029] Alternatively, in one or more embodiments, any transparent material known in the art, that may allow viewing of the swellable packer element 204 from outside of the housing 205, may be disposed within the outer shell 207. In one or more embodiments, a gap may be formed between the outer shell 207 and the inner tubing 206, in which a fluid may be introduced, or disposed, in the gap formed between the outer shell 207 and the inner tubing 206. As discussed above, introducing fluid in the gap formed between the outer shell 207 and the inner tubing 206 may help maintain a balanced, e.g. , minimal, differential pressure on the inner tube 206.

[0030] In one or more embodiments, the housing 205 may include a first end cap 208 and a second end cap 209. As shown, the first end cap 208 is threadably engaged with a top end of the housing 205 of the measurement apparatus 201, and the second end cap 209 is threadably engaged with a bottom end of the housing 205 of the measurement apparatus 201. Further, in one or more embodiments, a first sampling port (not shown) may be formed on the first end cap 208, and a second sampling port (not shown) may be formed on the second end cap 209. The first sampling port and the second sampling port may allow fluids contained within the housing 205 of the measurement apparatus 201 to be removed, e.g. , sampled, from the housing 205. As discussed above, in one or more embodiments, an impeller mixer (not shown), e.g. , the impeller mixer 115 of Figure 1, may be coupled to an end of the housing and may be configured to mix contents received within the housing therein. For example, the impeller mixer may be a magnetically coupled impeller mixer and may be coupled to the second end cap 209 of the housing 205 of the measurement apparatus 201.

[0031] Still referring to Figure 2, a first port 210 may be formed near the top end of the housing 205. In one or more embodiments, the first port 210 may be used as an entry port to introduce fluid, e.g. , a trigger fluid, into the housing 205, to induce swelling of the swellable packer element 204. However, those having ordinary skill in the art will appreciate that the first port 210 may be formed on any part of the housing 205. For example, in one or more embodiments, the first port 210 may be formed near the bottom end of the housing 205.

[0032] Further, those having ordinary skill in the art will appreciate that the first port 210 may be used for purposes other than to introduce a fluid into the housing 205. For example, in one or more embodiments, the first port 210 may be used to remove, or sample, fluid from the housing 205. Alternatively, in one or more embodiments, the first port 210 may be used to make the housing 205 a HPHT environment, and may also be used to introduce sour, e.g. sulfuric, fluids into the housing 205. Furthermore, those having ordinary skill in the art will appreciate that the trigger fluid to induce swelling of the swellable packer element 204 may be any fluid, i.e., gas or liquid, that is capable of causing, or inducing, swelling of any of the swellable materials listed above.

[0033] Referring now to Figure 3, a cross-sectional schematic view of a swellable packer element 304 disposed within a housing 305 of a measurement apparatus 301, according to embodiments disclosed herein, is shown. In one or more embodiments, the swellable packer element 304 may disposed within the housing 305, and a first biasing element 302 may be coupled between a first end of the housing 305 and the swellable packer element 304, and a second biasing element 303 may be coupled between a second end of the housing 305 and the swellable packer element 304. As shown, the first biasing element 302 is coupled between a top end of the housing 305 and the swellable packer element 304, and the second biasing element 303 is coupled to a bottom end of the housing 305 and the swellable packer element 304. Those having ordinary skill in the art will appreciate that one or more biasing elements may be used in the measurement apparatus 301. For example, one, two, three, four, or more biasing elements, in series or in parallel, may be used in the measurement apparatus 301.

[0034] In one or more embodiments, each of the first biasing element 302 and the second biasing element 303 may be springs, e.g., calibrated springs, in which a spring coefficient of each of the springs may be known. As such, a force exerted on the springs by the swellable packer element 304 may be calculated using known spring characteristics, e.g., spring coefficients, of each of the springs and the displacements of the springs, caused by a swelling of the swellable packer element 304. For example, the force exerted on the first biasing member 302 by the swellable packer element 304 may be determined by multiplying the spring coefficient of the first biasing member 302 by the displacement of the first biasing member 302, caused by the swelling of the swellable packer element 304. Those having ordinary skill in the art will appreciate that the term "spring coefficient," as used herein, may be constant and may also be functions for non-linear springs.

[0035] Similarly, the force exerted on the second biasing member 303 by the swellable packer element 304 may be determined by multiplying the spring coefficient of the second biasing member 303 by the displacement of the second biasing member 303, caused by the swelling of the swellable packer element 304. The displacement of each of the first biasing member 302 and the second biasing member 303 may be observed, from outside of the housing 305, through the aperture (not shown), e.g., the aperture 225 of Figure 2, formed in the outer shell (not shown), e.g., the outer shell 207 of Figure 2, of the housing 305.

[0036] In one or more embodiments, as the swellable packer element 304 swells, the swellable packer element 304 may cause the first biasing element 302 to be displaced in the direction of arrow 331. Similarly, in one or more embodiments, as the swellable packer element 304 swells, the swellable packer element 304 may cause the second biasing element 303 to be displaced in the direction of arrow 332. As such, the measurement apparatus 301, in accordance with the present disclosure, may be used to measure a force of the swellable packer element 304 as the swellable packer element 304 swells from a trigger fluid and/or reacts to a sweet/sour, HPHT, and/or corrosive environment.

[0037] Referring to Figure 4, a cross-sectional schematic view of a measurement apparatus 401 having a first sampling port 410 and a second sampling port 411, according to embodiments disclosed herein, is shown. The measurement apparatus 401 may include a housing 405 having a first end cap 408 and a second end cap 409. Further, in one or more embodiments, the first sampling port 410 may be formed, or disposed, on the first end cap 408, and the second sampling port 411 may be formed, or disposed, on the second end cap 409. [0038] As discussed above, each of the first sampling port 410 and the second sampling port 411 may allow fluids contained within the housing 205 of the measurement apparatus 201 to be removed, e.g. , sampled, from the housing 205. Further, as discussed above, those having ordinary skill in the art will appreciate that each of the first sampling port 410 and the second sampling port 411 may be used to make the housing 405 a HPHT environment, and may also be used to introduce sour, e.g. sulfuric, fluids into the housing 405. Those having ordinary skill in the art will also appreciate that each of the first sampling port 410 and the second sampling port 411 may be formed on any region of the housing 405, and may not be limited to being formed on a first end cap 408 and a second end cap 409, respectively.

[0039] As shown in Figure 4, a gas 435 and a liquid 436 are disposed within the housing

405. In one or more embodiments, the gas 435 and the liquid 436 may be different phases of the same fluid, e.g. , a trigger fluid, which may include HPHT halides, water (H ₂ 0), hydrogen sulfide (H ₂ S), carbon dioxide (C0 ₂ ), and Ci-C _n . Alternatively, the gas 435 and the liquid 436 may be different phases of different fluids, which may include any of the fluids, or any combination of the fluids, listed above. In one or more embodiments, the first sampling port 410 may be used to remove, or sample, the gas 435 from the housing 405. Similarly, in one or more embodiments, the second sampling port 411 may be used to remove, or sample, the liquid 436 from the housing 405.

[0040] A method of measurement, according to embodiments disclosed herein, may include measuring a characteristic of a swellable packer element disposed within a housing, the housing having at least one aperture formed therein, introducing a trigger fluid into the housing and into the swellable packer element, observing the swellable packer element through the at least one aperture of the housing; and re-measuring the characteristic of the swellable packer element through the at least one aperture.

[0041] The method may also include determining a force of the swellable packer element on at least one biasing element, based on the measuring and re-measuring of the characteristic of the swellable packer element. According to one or more aspects, the characteristic of the swellable packer element may be a dimension of the swellable packer element, e.g. a height of the swellable packer element. Further, the method may also include determining a force of the swellable packer element on the at least one biasing member, based on the measuring and re-measuring of the height of the swellable packer element and a spring coefficient of the at least one biasing element.

[0042] For example, referring to Figure 5, a measurement process 540, according to embodiments disclosed herein, is shown. The measurement process 540 may include calibrating the swellable packer element per well conditions, 541. Further, a visual optical cell, e.g., a measurement apparatus in accordance with the present disclosure, may be provided to visibly measure the swellable packer element, 542. For example, a characteristic of a swellable packer element disposed within the measurement apparatus may be visually measured, and re-measured, from outside of the measurement apparatus.

[0043] Furthermore, the process 540 may include making an in- situ force measurement of the swellable packer element on at least one biasing member, 543. Various fluids, such as trigger fluids, and including HPHT halides, water (H ₂ 0), hydrogen sulfide (H ₂ S), carbon dioxide (C0 ₂ ), and C -C _n may be introduced into a housing of the measurement apparatus, 544. Further, visual in-situ measurements of the swellable packer element may be made, including dimension measurements, e.g., swell and shrinkage measurements, force measurements, sealing integrity measurements, e.g., inspecting for the onset of cracks and failure within the swellable packer element, as well as geometric measurements, 545.

[0044] Referring back to Figure 2, measuring a characteristic of the swellable packer element 204 disposed within the housing 205 may be done by visually inspecting the swellable packer element 204 through the aperture 225 formed in the outer shell 207 of the housing 205. According to one or more aspects, the characteristic of the swellable packer element 204 may be a dimension, e.g., a height of the swellable packer element 204. Alternatively, the characteristic of the swellable packer element 204 may be a sealing integrity of the swellable packer element 204. According to one or more aspects, measuring the sealing integrity of the swellable packer element 204 may include visually inspecting the swellable packer element 204 for cracks and failure. Those having ordinary skill in the art will appreciate that a dimension of the swellable packer element 204 may include dimensions of the swellable packer element 204 other than height. For example, a dimension of the swellable packer element 204 may include a width, depth, or shape of the swellable packer element 204. [0045] Still referring to Figure 2, a trigger fluid may be introduced into the housing 205 and into the swellable packer element 204 through the first port 210. As discussed above, the first port 210 may be used as an entry port to introduce fluid, e.g., a trigger fluid, into the housing 205, to induce swelling of the swellable packer element 204.

[0046] Further, the swellable packer element 204 may be observed through the at least one aperture 225, or slot, formed in the outer shell 207 of the housing 205. As discussed above, one or more transparent, tempered glass plates (not shown) may be disposed within the outer shell 207 of the housing 205 to allow visual observation of contents within the inner tube 206, e.g., within the at least one aperture 225. Further, as discussed above, the inner tubing 206 may include PYREX glass, which may also be transparent. As such, according to one or more aspects, the swellable packer element 204 may be visually observed from outside of the housing 205, through the at least one aperture 225 and through the inner tubing 206.

[0047] According to one or more aspects, re-measuring the characteristic of the swellable packer element 204 disposed within the housing 205 may also be done by visually inspecting the swellable packer element 204 through the aperture 225 formed in the outer shell 207 of the housing 205. For example, as discussed above, the characteristic of the swellable packer element 204 may be a dimension, e.g., a height of the swellable packer element 204. Alternatively, the characteristic of the swellable packer element 204 may be a sealing integrity of the swellable packer element 204.

[0048] According to one or more aspects, measuring the sealing integrity of the swellable packer element 204 may include visually inspecting the swellable packer element 204 for cracks and failure. In other words, a height of the swellable packer element 204 may be measured before the introduction of the trigger fluid, and re-measured after the introduction of the trigger fluid. Similarly, the swellable packer element 204 may be inspected for cracks and failure both before and after the introduction of the trigger fluid. Further, either, or all of, characteristics described above may be measured before and after exposing the swellable packer element to sour, HPHT conditions.

[0049] Referring back to Figure 3, determining the force of the swellable packer element

304 on the at least one biasing element, i.e., the first biasing element 302 and the second biasing element 303, based on the measuring and re-measuring of the height of the swellable packer element 302 and a spring coefficient of the at least one biasing element may be done by visually observing and inspecting a change in the height of the swellable packer element 302.

[0050] For example, as discussed above, each of the first biasing element 302 and the second biasing element 303 may be springs, e.g., calibrated springs, in which a spring coefficient of each of the springs may be known. As such, a force exerted on the springs by the swellable packer element 304 may be calculated using the known spring coefficients of each of the springs and the displacements of the springs, caused by a swelling of the swellable packer element 304. For example, the force exerted on the first biasing member 302 by the swellable packer element 304 may be determined by multiplying the spring coefficient of the first biasing member 302 by the displacement of the first biasing member 302, caused by the swelling of the swellable packer element 304.

[0051] Similarly, the force exerted on the second biasing member 303 by the swellable packer element 304 may be determined by multiplying the spring coefficient of the second biasing member 303 by the displacement of the second biasing member 303, caused by the swelling of the swellable packer element 304. The displacement of each of the first biasing member 302 and the second biasing member 303 may be observed, from outside of the housing 305, through the aperture (not shown), e.g., the aperture 225 of Figure 2, formed in the outer shell (not shown), e.g., the outer shell 207 of Figure 2, of the housing 305. In one or more embodiments, as the swellable packer element 304 swells, the swellable packer element 304 may cause the first biasing element 302 to be displaced in the direction of arrow 331. Similarly, in one or more embodiments, as the swellable packer element 304 swells, the swellable packer element 304 may cause the second biasing element 303 to be displaced in the direction of arrow 332.

[0052] As discussed above, in one or more embodiments, the housing may include an outer layer and an inner tube. The method may also include introducing a fluid into a gap formed between the outer layer and the inner tube. As discussed above, referring back to Figure 2, introducing fluid in the gap formed between the outer shell 207 and the inner tubing 206 may help maintain a balanced, e.g., minimal, differential pressure on the inner tube 206. Maintaining a balanced differential pressure on the inner tube 206 may help preserve the structural integrity of the housing 205.

[0053] Advantageously, embodiments disclosed herein may provide an apparatus and a method of measurement that may be able to accurately make visual, in-situ measurements of the swell of a swellable packer, including geometric and dimensional changes. Further, visual, in-situ determinations of onset cracking and failure of a swellable packer may be made, as well as a measurement of the shrinkage of a swellable packer once it is removed from a sour, HPHT environment. Furthermore, in-situ force measurements of the swellable packer due to swell may be taken. Additionally, all of the measurements and observations discussed above may be made accurately in sour, HPHT environments. However, those having ordinary skill in the art will appreciate that embodiments disclosed herein are not limited to being used in sour, HPHT environments. For example, embodiments disclosed herein may be used in sweet environments.

[0054] While embodiments have been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of embodiments disclosed herein. Accordingly, the scope of embodiments disclosed herein should be limited only by the attached claims.