Patent Publication Number: US-8973657-B2

Title: Gas generator for pressurizing downhole samples

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 12/962,621 filed Dec. 7, 2010, published as U.S. Patent Application Publication No. US 2012-0138292 A1, and entitled “Gas Generator for Pressurizing Downhole Samples,” which is hereby incorporated by reference in its entirety. 
    
    
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     Not applicable. 
     REFERENCE TO A MICROFICHE APPENDIX 
     Not applicable. 
     BACKGROUND 
     In the subterranean well drilling and completion art, tests are performed on formations intersected by a wellbore. Such tests can be performed in order to determine geological or other physical properties of the formation and fluids contained therein. For example, parameters such as permeability, porosity, fluid resistivity, temperature, pressure, and bubble point may be determined. These and other characteristics of the formation and fluid contained therein may be determined by performing tests on the formation before the well is completed and placed in service. 
     One type of testing procedure measures the composition of the formation fluids by obtaining a fluid sample from the formation. In order to obtain a representative sample, the sample is preserved as it exists within the formation. A general sampling procedure involves lowering a sample chamber into the wellbore, obtaining a sample, and retrieving the sample in the sampling chamber to the surface for analysis. It has been found, however, that as the fluid sample is retrieved to the surface, the temperature and pressure of the fluid sample can decrease. This change in properties can cause the fluid sample to approach or reach saturation pressure creating the possibility of phase separation, which can result in asphaltene deposition and/or flashing of entrained gasses present in the fluid sample. Once such a process occurs, the resulting phase separation may be irreversible so that a representative sample cannot be obtained without re-running the procedure to take an additional sample. 
     SUMMARY 
     In an embodiment, an apparatus for obtaining fluid samples in a subterranean wellbore comprises a carrier assembly configured to be disposed in a subterranean wellbore; a sampling chamber operably associated with the carrier assembly; a pressure assembly coupled to the sampling chamber and configured to pressurize a fluid sample obtained in the sampling chamber, wherein the pressure assembly is configured to contain a pressure generating agent; an activation mechanism configured to activate the pressure generating agent; and a power device operably associated with the carrier assembly and configured to provide an impulse for activating the activation mechanism, wherein the power device is not disposed on the pressure assembly. 
     In an embodiment, a method comprises positioning a fluid sampler comprising a sampling chamber, a pressure assembly, and an activation mechanism in a subterranean wellbore, wherein the pressure assembly comprises a pressure generating agent that comprises an organic solid composition, a urea, a multi-component system, or any combination thereof; obtaining a fluid sample in the sampling chamber; activating, within the subterranean wellbore, the pressure generating agent with the activation mechanism to generate a pressurized fluid that is coupled to the sampling chamber; and pressurizing the fluid sample using the pressurized fluid. 
     In an embodiment, a method of generating pressure within a subterranean wellbore comprises positioning an activation mechanism and a pressure assembly comprising a pressure generating agent within a subterranean wellbore; activating, within the subterranean wellbore, the pressure generating agent with the activation mechanism to generate a pressurized fluid; and using the pressurized fluid to operate at least one tool disposed in the subterranean wellbore and coupled to the pressurized fluid. 
     These and other features will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings and claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the present disclosure, reference is now made to the following brief description, taken in connection with the accompanying drawings and detailed description, wherein like reference numerals represent like parts. 
         FIG. 1  is a cross-sectional view of an axial portion of an embodiment of a pressure assembly in accordance with the present disclosure; 
         FIG. 2A-2F  are cross sectional views of successive axial portions of an embodiment of a sampling section of a fluid sampler in accordance with the present disclosure; and 
         FIG. 3  is an illustration of a wellbore servicing system according to an embodiment of the present disclosure. 
         FIG. 4  is a schematic illustration of an embodiment of a plurality of sampling chambers coupled to a pressure source. 
         FIG. 5  is a schematic illustration of an embodiment of a sampling chamber coupled to an actuator and pressure source. 
     
    
    
     DETAILED DESCRIPTION 
     It should be understood at the outset that although illustrative implementations of one or more embodiments are illustrated below, the disclosed systems and methods may be implemented using any number of techniques, whether currently known or not yet in existence. The disclosure should in no way be limited to the illustrative implementations, drawings, and techniques illustrated below, but may be modified within the scope of the appended claims along with their full scope of equivalents. 
     The present disclosure provides a fluid sampling apparatus and a method for obtaining fluid samples from a formation without the need for a highly pressurized gas being charged to the apparatus on the surface of a wellbore. In a typical sampling procedure, a sample of the formation fluids may be obtained by lowering a sampling tool having a sampling chamber and a pressurized gas reservoir into the wellbore on a conveyance such as a wireline, slick line, coiled tubing, jointed tubing or the like. When the sampling tool reaches the desired depth, one or more ports are opened to allow collection of the formation fluids. Once the ports are opened, formation fluids travel through the ports and a sample of the formation fluids is collected within the sampling chamber of the sampling tool. It is understood that in practice, when taking a sample in a downhole environment, other fluids in addition to the formation fluids may be captured, for example some admixture of wellbore fluid, drilling mud, cement, acidation fluid, fracturing fluid, or other fluid that may be present in the wellbore. The pressurized gas reservoir may then be opened to allow the pressurized gas to pressurize the sample. After the sample has been collected and pressurized, the sampling tool may be withdrawn from the wellbore so that the formation fluid sample may be analyzed. The pressurized gas reservoir is filled at the surface of the wellbore with a gas such as nitrogen, and the gas reservoir pressures can be as high as 15,000 pounds per square inch (“psi”). The resulting pressurized fluid container may then present a safety risk to the personnel working around the wellbore prior to the tool being placed into the subterranean formation. 
     As disclosed herein, an alternative means of providing a pressurized gas reservoir includes the use of a pressure generating agent in an apparatus to provide a source of pressure. In some embodiments, the pressure generating agent can be a solid component, a liquid component, or any combination of components. An activation mechanism may be used to trigger the generation of pressure from the pressure generating agent through, for example, a chemical reaction. The resulting pressure may then be used to operate one or more tools in a wellbore, including providing a source of pressurized gas or fluid for pressurizing a sample of reservoir fluid. 
     The use of a pressure generating agent to create a source of pressure down hole can allow for the elimination of a high pressure gas within a wellbore tool at the surface of the well, prior to use of the tool. The use of the pressure generating agent can also allow for the pressure charging source (e.g., a high-pressure nitrogen source) to be eliminated at the well site, which may help to limit the high pressure sources located at the surface of the well. The elimination of a potentially dangerous pressure source may help prevent accidents at the well site. For example, the pressure generating agent may be maintained at near atmospheric pressure within a downhole tool until after the tool is disposed within the subterranean formation. Thus, the danger associated with the use of a high pressure fluid may be avoided until the tool is safely within the wellbore. Further, the charging vessel or storage vessel from which the downhole tool might otherwise be charged may be obviated, thereby removing another potential hazard from the well site. In some contexts herein the term fluid may refer to both liquids and gases, where the term is used to point out the ease of flow of the subject material and/or composition. 
     Turning now to  FIG. 1 , an embodiment of an activation mechanism and a pressure assembly comprising a pressure generating agent is illustrated. The pressure assembly  102  comprises an outer housing or carrier  104  that may comprise a cylindrical metallic body. The body may be constructed of any appropriate materials suitable for use in wellbore environments and configured to contain the pressure generated within the pressure assembly  102 . In an embodiment, the pressure assembly  102  may be capable of containing up to about 15,000 psi, alternatively about 13,000 psi, or still alternatively about 10,000 psi. In an embodiment, the housing may be constructed of carbon steel or stainless steel. In an embodiment, the pressure assembly  102  includes a first end  106  and a second end  108 . The first end  106  and second end  108  may be configured to be coupled with additional wellbore components. For example, the first end  106 , the second end  108 , or both may be threaded and act as a box connector and/or a pin connector in a wellbore tool string. Suitable connections may be provided to allow the pressure assembly  102  to be sealingly engaged to additional wellbore components, as desired. 
     In an embodiment, the pressure assembly  102  may comprise an activation mechanism  112  within the outer housing  104 . In an embodiment, the activation mechanism  112  may comprise any suitable device configured to cause a pressure generating agent  127  to generate a pressure, or any means for initiating a pressure increase from a pressure generating agent  127 . Suitable activation mechanisms may include, but are not limited to, percussion caps, electrically initiated sparking devices, and/or electrically initiated heat sources (e.g., filaments). Suitable electrical sources for use with an activation mechanism  112  may include, but are not limited to, batteries (e.g., high temperature batteries for use in wellbore environments) and piezo electric elements capable of generating an electrical charge sufficient to activate an activation mechanism. A power device configured to provide an impulse in the form of a physical force to a percussion cap or an electrical current to an electrically initiated activation mechanism may be disposed within the pressure assembly  102 , or may not be disposed on or within the pressure assembly. Rather, the power device may be disposed on a separate device in fluid, mechanical, and/or electrical communication with the pressure assembly  102 . For example, an electrical source may be disposed on an additional device mechanically coupled to the pressure assembly  102  such that when a piston or other slidingly engaged device within the additional device is sufficiently displaced, the electrical source may contact a pin connector on the pressure assembly  102  and activate the activation mechanism  112 . In another embodiment, the power device may comprise a firing pin configured to provide a physical force to a percussion cap to initiate the activation mechanism. 
     In an embodiment shown in  FIG. 1 , the pressure assembly  102  comprises a pin connector  109 , at least one connector wire  110 , and an activation mechanism  112 . The pin connector  109  may be any suitable structure for receiving an electrically conducting element and conducting an electrical charge through connector wire  110 , which may be electrically insulated from the surrounding structures in the pressure assembly  102 . The activation mechanism  112  may be configured to receive at least one connector wire  110  from the pin connector  109  for initiating the activation mechanism. In some embodiments, only one connector wire  110  is provided from the pin connector if the remaining structures in the pressure assembly  102  are electrically conductive. In some embodiments, a plurality of connector wires  110  may be used, for example, to avoid placing an electrical charge on the other structures in the pressure assembly  102 . In an embodiment, one or more redundant connector wires  110  can be used to ensure activation of the activation mechanism  112 . The activation mechanism  112  may be coupled to a pressure chamber  114  such that the activation mechanism  112  is capable of activating the pressure generating agent  127  disposed within the pressure chamber  114 . 
     In an embodiment, a suitable activation mechanism may include any device capable of contacting a plurality of components capable of generating pressure. Suitable activation mechanisms may include, but are not limited to, rupture discs, valves, sliding barriers, diaphragms configured to be punctured, or any other separation device capable of being opened to allow fluid communication between two components. The activation mechanisms of this type can be actuated by electrical or mechanical means. 
     The pressure chamber  114  may be centrally disposed within the pressure assembly  102  and may be configured to contain a pressure generating agent  127 . The pressure chamber  114  may be in fluid communication with the first end  106  of the pressure assembly  102  through a fluid channel  116  and a fluid passageway  118 . In some embodiments not shown in  FIG. 1 , the pressure chamber  114  may be coupled to the first end  106  of the pressure assembly  102  through a mechanical means (e.g., a sliding piston). The pressure assembly  102  may include an optional pressure disk  120  disposed between the pin connector  109  and a body  122 . In an embodiment, the pressure disk  120  may be a rupture disk, however, other types of pressure disks that provide a seal, such as a metal-to-metal seal, between pressure disk holder pin connector  109  and body  122  could also be used including a pressure membrane. The pressure disk  120  may seal the pressure chamber  114  and any pressure generating agent  127  prior to activation, which may prevent contamination of the pressure generating agent  127 . 
     In an embodiment, the pressure chamber  114  is configured to contain a quantity of pressure generating agent  127 . A pressure generating agent may comprise any suitable composition capable of generating at least about 1,000 psi, alternatively about 2,000 psi, or alternatively about 3,000 psi when activated within the wellbore. In an embodiment, the pressure generating agent may comprise a solid composition capable of reacting and/or decomposing upon activation to generate one or more gases and/or fluids within the pressure assembly  102 . 
     In an embodiment, a solid composition suitable for use as a pressure generating agent may comprise a fuel, an oxidizer, and any number of additives suitable for use with gas generating agents. Fuels suitable for use as a solid pressure generating agent may include any compound capable of reacting to form one or more gases at an increased pressure. In an embodiment, the fuel may generally comprise an organic composition. In an embodiment, compositions suitable for use as a fuel may include, but are not limited to, materials incorporating tetrazines, tetrazine derivatives, azides (e.g., sodium azide), azide derivatives, azoles, azole derivatives (e.g., triazole derivatives, tetrazole derivatives, oxadiazole derivatives), guanidine derivatives, azodicarbon amide derivatives, hydrazine derivatives, urea derivatives, ammine complexes, nitrocellulose, any derivatives thereof, any salts thereof, and any combinations thereof. In an embodiment, the fuel may generally comprise a thermite solid composition. 
     Oxidizers generally assist in the reaction of the fuels to form one or more gases. Suitable oxidizers may include, but are not limited to, chlorates, perchlorates (e.g., potassium perchlorate, lithium perchlorate, and ammonium perchlorate), oxides (e.g., iron oxide), nitrites, nitrates (e.g., ammonium nitrate, potassium nitrate, and strontium nitrate), peroxides (e.g., metal peroxides), hydroxides (e.g., metal hydroxides), hydrides (e.g., sodium borohydride), dicyanamide compounds, any derivatives thereof, any salts thereof, and any combinations thereof. 
     Additives may include, but are not limited to, binders, coolants, slag forming agents, and processing agents. For example, coolants may include, but are not limited to, metal carbonates, metal bicarbonates, metal oxalates, and any combinations thereof. Slag forming agents may include, but are not limited to, clays, silicas, aluminas, glass, and any combinations thereof. 
     The solid pressure generating agents may be supplied by suppliers known in the art. Typical or known suppliers include Aldrich, Fisher Chemical companies, and Nippon Carbide. Solid pressure generating agents may be available in a variety of shapes and forms. For example, a solid pressure generating agent may be available in the shape of a pellet, a circular column, a tube, a disk, or a hollow body with both ends closed. The exact composition and form of the pressure generating agent may depend on a variety of factors including, but not limited to, temperature stability, maximum pressure generation, combustion temperature, and ignition characteristics. 
     In an embodiment, additional pressure generating agents suitable for use in the pressure assembly  102  may include multi-component systems comprising a plurality of reactive components that react when contacted. In this embodiment, the activation device may comprise any device capable of introducing at least one component to another. For example, the activation device may include, but is not limited to, a valving assembly for introducing one component into a chamber containing a second component. Alternatively, the activation device may comprise a percussion cap capable of breaking a seal between two components stored in the same or different chambers. In an embodiment, a multi-components system may comprise the use of a solid carbonate and/or bicarbonate (e.g., a metal bicarbonate such as sodium bicarbonate or calcium carbonate) in combination with a liquid and/or solid acid (e.g., an organic acid such as acetic acid, or a mineral acid such as hydrochloric acid). When combined, this embodiment of a multi-component system will result in the release of carbon dioxide, which may provide the increased pressure within the pressure assembly  102 . 
     In an embodiment, the activation mechanism  112  and the pressure assembly  102  comprising a pressure generating agent  127  may be used as a source of pressure in a wellbore disposed in a subterranean formation. The pressure provided by the pressure assembly  102  may be used to operate at least one tool disposed in the wellbore that is coupled to the pressure assembly  102 . In an embodiment, the activation mechanism  112  and the pressure assembly  102  may be positioned within a wellbore disposed in a subterranean formation. The pressure generating agent  127  can be disposed in the pressure chamber  114  prior to the pressure assembly  102  being placed within the wellbore. The pressure assembly  102  may be coupled to a tool at the surface of the wellbore and/or within the wellbore using any suitable techniques known in the art. 
     Once disposed in the wellbore, the activation mechanism  112  may be used to activate the pressure generating agent  127  to generate a pressurized fluid. The pressure generating agent may generate at least about 1,000 psi, at least about 2,000 psi, or at least about 3,000 psi of pressure within the pressure assembly  102 . In an embodiment, the pressure generating agent may generate less than about 15,000 psi, less than about 13,000 psi, or less than about 10,000 psi of pressure within the pressure assembly  102 . In an embodiment, a pressure regulation device can be incorporated into the pressure assembly  102  to maintain the pressure in the pressure chamber  114  below a desired value. For example, the pressure regulation device may vent any additional pressured fluid in excess of the amount needed to generate the desired pressure in the pressure reservoir to the wellbore. The pressurized fluid may then be used to operate one or more devices (e.g., downhole tools) disposed in the wellbore. For example, one or more of the devices coupled to (e.g., in fluid communication with) the pressure assembly  102  may be operated using the pressure generated by the activation of the pressure generating agent  127 . 
     In some embodiments, the pressure generating agent  127  may be activated soon after being disposed within the wellbore. In these embodiments, the pressure assembly  102  may comprise additional devices, such as selectively operable valves to allow the pressure assembly  102  to act as a pressure reservoir for use within the wellbore. In some embodiments, the pressure generating agent  127  may not be activated until a desired time, allowing the pressure created by the activation of the pressure generating agent  127  to be used at approximately the same time it is created. 
     In some embodiments, the pressure created by the activation of the pressure generating agent  127  may be used for a single operation of one or more devices within the wellbore. In some embodiments, the pressure may be used to perform a plurality of operations of a device within the wellbore. In these embodiments, the pressure created by the activation of the pressure generating agent  127  may be stored in a pressure reservoir of a suitable size within the pressure assembly  102 . The pressure reservoir may then be used for a plurality of operations of one or more devices. In another embodiment, a plurality of pressure assemblies  102  may be disposed within the wellbore to provide a plurality of operations of one or more devices within the wellbore. In this embodiment, a plurality of pressure chambers  114  and corresponding activation mechanisms  112  may be provided in a single pressure assembly  102 , and/or a plurality of pressure assemblies  102  may be provided within the wellbore, all coupled to a device or devices to allow for the plurality of operations of the device or devices. 
     In an embodiment, the apparatus and device of the present disclosure may be used to operate one or more devices in a wellbore disposed in a subterranean formation. In an embodiment, the device may comprise a fluid sampler for obtaining fluid samples from within a wellbore and maintaining the sample in a single phase upon retrieval of the sample to the surface. An embodiment of a device coupled to a pressure assembly  102  is illustrated in  FIGS. 2A-2F , where the device and pressure assembly  102  are illustrated in serial views (e.g., the lower end of  FIG. 2A  would be coupled to the upper end of  FIG. 2B  and so forth). As shown in  FIGS. 2A-2F , a fluid sampling chamber  200  is shown which may be placed in a fluid sampler comprising a carrier (not shown) (e.g., housing or carrier  104  of  FIG. 1 ) having a pressure assembly  102  coupled thereto, for use in obtaining one or more fluid samples. The sampling chamber  200  may be coupled to a carrier that may also include an actuator (not shown) (e.g., actuator  103  of  FIG. 5 ). In an embodiment, the sampling chamber  200  and the carrier may comprise a part of a wellbore servicing system, as described in more detail below. In an embodiment, one or more sampling chambers  200  as described herein can be disposed in the carrier. 
     In an embodiment, a passage  210  in an upper portion of the sampling chamber  200  (see  FIG. 2A ) may be placed in communication with a longitudinally extending internal fluid passageway formed completely through the carrier when the fluid sampling operation is initiated using an actuator. In this way, the internal fluid passageway becomes a portion of an internal passage in a tubular string, which may be used to dispose the fluid sampler within the wellbore as discussed in more detail below. Passage  210  in the upper portion of sampling chamber  200  is in communication with a sample chamber  214  via a check valve  216 . Check valve  216  permits fluid to flow from passage  210  into sample chamber  214 , but prevents fluid from escaping from sample chamber  214  to passage  210 . 
     In some embodiments, a debris trap may be used with the fluid sampler. In these embodiments, a debris trap piston  218  is disposed within housing  202  and separates sample chamber  214  from a meter fluid chamber  220 . When a fluid sample is received in sample chamber  214 , debris trap piston  218  is displaced downwardly relative to housing  202  to expand sample chamber  214 . Prior to such downward displacement of debris trap piston  218 , however, fluid flows through sample chamber  214  and passageway  222  of piston  218  into debris chamber  226  of debris trap piston  218 . The fluid received in debris chamber  226  is prevented from escaping back into sample chamber  214  due to the relative cross sectional areas of passageway  222  and debris chamber  226  as well as the pressure maintained on debris chamber  226  from sample chamber  214  via passageway  222 . An optional check valve (not pictured) may be disposed within passageway  222  if desired. Such a check valve would operate to allow fluid to flow from the sample chamber  214  into the debris chamber  226  and prevent flow from debris chamber  226  into the sample chamber  214 . In this manner, the fluid initially received into sample chamber  214  is trapped in debris chamber  226 . Debris chamber  226  thus permits this initially received fluid to be isolated from the fluid sample later received in sample chamber  214 . Debris trap piston  218  can include a magnetic locator  224  used as a reference to determine the level of displacement of debris trap piston  218  and thus the volume within sample chamber  214  after a sample has been obtained. 
     In an embodiment, meter fluid chamber  220  initially contains a metering fluid, such as a hydraulic fluid, silicone oil or the like. A flow restrictor  234  and a check valve  236  control flow between chamber  220  and an atmospheric chamber  238  that initially contains a gas at a relatively low pressure such as air at atmospheric pressure. A collapsible piston assembly  240  includes a prong  242  which initially maintains check valve  244  off seat, so that flow in both directions is permitted through check valve  244  between chambers  220 ,  238 . When elevated pressure is applied to chamber  238 , however, as described more fully below, piston assembly  240  collapses axially, and prong  242  will no longer maintain check valve  244  off seat, thereby preventing flow from chamber  220  to chamber  238 . 
     A piston  246  disposed within housing  202  separates chamber  238  from a longitudinally extending atmospheric chamber  248  that initially contains a gas at a relatively low pressure such as air at atmospheric pressure. Piston  246  can include a magnetic locator  247  used as a reference to determine the level of displacement of piston  246  and thus the volume within chamber  238  after a sample has been obtained. Piston  246  comprises a trigger assembly  250  at its lower end. In the illustrated embodiment, trigger assembly  250  is threadably coupled to piston  246  which creates a compression connection between a trigger assembly body  252  and a pin connection  254 . Alternatively, pin connection  254  may be coupled to trigger assembly body  252  via threading, welding, friction or other suitable technique. Pin connection  254  comprises a hollow interior where one or more suitable sources of an electrical charge  251  (e.g., high temperature lithium batteries) are configured to provide an electrical current through the tip of pin connection  254 . The tip of pin connection  254  may be threaded or otherwise removably engaged to the body of the pin connection  254  to allow for replacement of the one or more batteries as needed. As discussed more fully below, pin connection  254  is used to actuate the activation mechanism  112  of the pressure assembly  102  when piston  246  is sufficiently displaced relative to housing  202 . 
     Below atmospheric chamber  248  and disposed within the longitudinal passageway of housing  202  is the pressure assembly  102 , as described above. The pressure assembly  102  may have a pin connector  109  configured to mate with the pin connection  254  on the piston  246 . In an embodiment, pin connector  109  is electrically coupled to an activation mechanism  112  through one or more connector wires  110 . The activation mechanism  112  is disposed in communication with a pressure chamber  114  configured to contain a pressure generating agent  127 , and is capable of activating the pressure generating agent  127  to produce an increased pressure in the pressure chamber  114 . Pressure chamber  114  is in fluid communication with fluid channel  116 , which is in fluid communication with atmospheric chamber  248  through the fluid channel  116  and fluid passageway  118 . A rupture disk, for example the pressure disk  120 , may be disposed in fluid channel  116  to prevent the flow of any fluids from atmospheric chamber  248  into the pressure chamber  114  until after the activation of the pressure generating agent  127  by the activation mechanism  112 . Upon activation of the pressure generating agent  127 , the rupture disk may be breached to allow flow of a pressurized fluid from the pressure chamber  114  to chamber  248 . 
     In an embodiment, a fluid sampler comprising a fluid sampling chamber  200  and associated pressure assembly  102  may comprise a portion of a wellbore servicing system as shown in  FIG. 3 . In an embodiment, the system  300  comprises a servicing rig  314  that extends over and around a wellbore  302  that penetrates a subterranean formation  304  for the purpose of recovering hydrocarbons, storing hydrocarbons, disposing of carbon dioxide, or the like. The wellbore  302  may be drilled into the subterranean formation  304  using any suitable drilling technique. While shown as extending vertically from the surface in  FIG. 3 , in some embodiments the wellbore  302  may be deviated, horizontal, and/or curved over at least some portions of the wellbore  302 . Reference to up or down will be made for purposes of description with “up,” “upper,” “upward,” or “upstream” meaning toward the surface of the wellbore and with “down,” “lower,” “downward,” or “downstream” meaning toward the terminal end of the wellbore, regardless of the wellbore orientation. 
     The servicing rig  314  may be one of a drilling rig, a completion rig, a workover rig, a servicing rig, or other mast structure and supports a toolstring  306  and a conveyance  312  in the wellbore  302 , but in other embodiments a different structure may support the toolstring  306  and the conveyance  312 , for example an injector head of a coiled tubing rigup. In an embodiment, the servicing rig  314  may comprise a derrick with a rig floor through which the toolstring  306  and conveyance  312  extends downward from the servicing rig  314  into the wellbore  302 . In some embodiments, such as in an off-shore location, the servicing rig  314  may be supported by piers extending downwards to a seabed. Alternatively, in some embodiments, the servicing rig  314  may be supported by columns sitting on hulls and/or pontoons that are ballasted below the water surface, which may be referred to as a semi-submersible platform or rig. In an off-shore location, a casing may extend from the servicing rig  314  to exclude sea water and contain drilling fluid returns. It is understood that other mechanical mechanisms, not shown, may control the run-in and withdrawal of the toolstring  306  and the conveyance  312  in the wellbore  302 , for example a draw works coupled to a hoisting apparatus, a slickline unit or a wireline unit including a winching apparatus, another servicing vehicle, a coiled tubing unit, and/or other apparatus. 
     The toolstring  306  may be comprised of one or more fluid samplers, which comprise a fluid sample chamber  200  and a pressure assembly  102 . The toolstring  306  may also comprise one or more additional downhole tools, for example a packer, retrievable bridge plug, and/or a setting tool. The conveyance  312  may be any of a string of jointed pipes, a slickline, a coiled tubing, a wireline, and other conveyances for the toolstring  306 . In another embodiment, the toolstring  306  may comprise additional downhole tools located above or below the fluid sampler. 
     The toolstring  306  may be coupled to the conveyance  312  at the surface and run into the wellbore casing  303 , for example a wireline unit coupled to the servicing rig  314  may run the toolstring  306  that is coupled to a wireline into the wellbore casing  303 . In an embodiment, the conveyance may be a wireline, an electrical line, a coiled tubing, a drill string, a tubing string, or other conveyance. At target depth, the actuator in the fluid sampler may be actuated to initiate the sampling of the formation fluid in response to a signal sent from the surface and/or in response to the expiration of a timer incorporated into the fluid sampler or fluid sampler carrier. 
     As described above with reference to  FIGS. 2A-2F , once the fluid sampler is in its operable configuration and is located at the desired position within the wellbore  302 , a fluid sample can be obtained in one or more sample chambers  214  by operating an actuator in the carrier to allow the formation fluids surrounding the carrier to flow into the sampling chamber. Fluid from the subterranean formation  304  can then enter passage  210  in the upper portion of the sampling chamber  200 . The fluid flows from passage  210  through check valve  216  to sample chamber  214 . It is noted that check valve  216  may include a restrictor pin  268  to prevent excessive travel of ball member  270  and over compression or recoil of spiral wound compression spring  272 . An initial volume of the fluid is trapped in debris chamber  226  of piston  218  as described above. Downward displacement of piston  218  is slowed by the metering fluid in chamber  220  flowing through restrictor  234 . Proper sizing of the restrictor can prevent the pressure of the fluid sample received in sample chamber  214  from dropping below its bubble point. 
     As piston  218  displaces downward, the metering fluid in chamber  220  flows through restrictor  234  into chamber  238 . At this point, prong  242  maintains check valve  244  off seat. The metering fluid received in chamber  238  causes piston  246  to displace downwardly. Eventually, pin connector  254  contacts pin connector  109  on the pressure assembly  102 . The resulting electrical charge causes activation mechanism  112  to activate the pressure generating agent  127  in pressure chamber  114 . The resulting pressure increase in pressure chamber  114  breaches rupture disk, for example the pressure disk  120 , permitting pressure from pressure assembly  102  to be applied to chamber  248 . Specifically, once the pressure generating agent  127  is activated, the pressure from pressure assembly  102  passes through fluid channel  116  and fluid passageway  118  to chamber  248 . Pressurization of chamber  248  also results in pressure being applied to chambers  238 ,  220  and thus to sample chamber  214 . 
     When the pressure from pressure assembly  102  is applied to chamber  238 , pins  278  are sheared allowing piston assembly  240  to collapse such that prong  242  no longer maintains check valve  244  off seat. Check valve  244  then prevents pressure from escaping from chamber  220  and sample chamber  214 . Check valve  216  also prevents escape of pressure from sample chamber  214 . In this manner, the fluid sample received in sample chamber  214  remains pressurized, which may prevent any phase separation of the fluid sample. 
     While several embodiments have been provided in the present disclosure, it should be understood that the disclosed systems and methods may be embodied in many other specific forms without departing from the spirit or scope of the present disclosure. The present examples are to be considered as illustrative and not restrictive, and the intention is not to be limited to the details given herein. For example, the various elements or components may be combined or integrated in another system or certain features may be omitted or not implemented. 
     Also, techniques, systems, subsystems, and methods described and illustrated in the various embodiments as discrete or separate may be combined or integrated with other systems, modules, techniques, or methods without departing from the scope of the present disclosure. Other items shown or discussed as directly coupled or communicating with each other may be indirectly coupled or communicating through some interface, device, or intermediate component, whether electrically, mechanically, or otherwise. Other examples of changes, substitutions, and alterations are ascertainable by one skilled in the art and could be made without departing from the spirit and scope disclosed herein.