Fluid sample chamber with non-reactive lining

Abstract

 An apparatus for retaining a well-fluid sample and a method for using the same. The apparatus comprises a variable volume sample chamber having interior surfaces of a nonreactive material, such as a ceramic, the interior surfaces defining a cavity (222). The sample chamber comprises a tubular member, a piston (226) slidingly engaged in the tubular member operable in response to fluid pressure within the sample chamber, a passageway (260) defined in the sample chamber and adapted for providing fluid communication between the cavity (222) and an area exterior the sample chamber, and a valve assembly (254) operable for selectively opening and closing the passageway (260).

Description

[0001] The invention relates to a well fluid sample retaining or storing device, and more particularly to a sample chamber for use in a sampler module or sample bottle having a non-reactive lining.

[0002] A common operation in reservoir evaluation operations is to collect reservoir fluid samples. These samples are generally trapped in the sample chamber of a well fluid sampler module which is retrieved to surface. A single sampling tool may hold a single or a plurality of sampler modules each having a sample chamber. Measuring instruments such as pressure and temperature gauges, may also be mounted in the sampling tool for evaluation of the well parameters. When the tool is at a desired depth in the well bore, the sampler module is opened or exposed to the well fluid, and the case is filled. The tool and sampler module may open in response to a signal from the surface or pressure exerted by the well fluid. Once filled, the sampler module is sealed and brought to the surface. At the surface, the sample is usually transferred into a sample bottle which is designed to contain high pressure samples in a safe manner, although the sample may remain in the sample module. The sample is stored, often for long periods of time, for later laboratory analysis. Typical sampling tools and methods are described in U.S. Patent 4,878,538 issued to Christensen, U.S. Patent 4,903,765 issued to Zunkel, U.S. Patent 4,883,123 issued to Zunkel, and U.S. Patent 5,240,072 issued to Schultz, et al., each of which is assigned to Halliburton, the assignee of the present invention.

[0003] Typically sample bottles and sampler modules are made of metallic alloys which are compatible with common hydrocarbon mixtures. Although the chamber materials are relatively non-reactive, there is still a very high probability that some amount of chemical reaction and absorption will occur between the chamber material and some of the sample constituents. This poses a problem in that if the reaction portion of the sample is in a very small concentration, most, if not all, of this component will be depleted through the chemical reaction and absorption. This will produce erroneous results when a lab analysis is performed on the sample. This problem can be very severe when samples are left in sample chambers for long periods of time. One object of this invention is to present a sample chamber, for use in a sampler module or sample bottle, which is virtually non-reactive with most of the chemicals encountered in a typical well fluid sample.

[0004] There are also difficulties in thoroughly cleaning metallic sample chambers. Contaminants tend to be absorbed into the pores of these materials. Once absorbed, the contaminants are difficult to clean out of the sample chambers. Incomplete cleaning can result in inaccuracies in testing of later samples, and the damage to the sample chamber shortens the life of the sampling tool or sample bottle. Another object of the invention is to present a sample chamber which is easy to clean and has a longer useful life than typical sample chambers.

[0005] The invention discloses a sample chamber with a non-reactive lining, preferably of ceramic. The sample chamber may take many forms depending on the vessel in which it is disposed, and the invention is not limited to the specific embodiments disclosed. For the purposes of explanation, sample chambers are explained in detail as disposed in a sampler module and a sample bottle. This disclosure describes a sampler module and a sample bottle having sample chambers which are constructed with non-reactive linings and parts, preferably of ceramic, which are nonporous and virtually nonreactive with most chemicals encountered in well fluids. A sampler module and a sample bottle are presented in which the well fluid sample is contained entirely by a ceramic liner, inserts, valves, and pistons. Inside the sample chamber there may be a ceramic ball for agitating the sample as it is drained.

[0006] A ceramic-to-ceramic seal is made between each of the chamber inserts and the ceramic liner, and between each valve dart and seat, as necessary. This allows the sample to be contained entirely within the chamber contacting only ceramic. The sample chamber may be used for shipping and storage purposes without degradation of the well fluid sample from chemical reaction with the sample chamber. This allows the sample to be stored for long periods of time in an inert chamber. The nonreactive nature of the lining makes sample degradation through absorption by or reaction with the sample chamber almost nonexistent. This allows for obtaining critical samples and makes long-term sample storage more feasible. Thorough cleaning of the wetted ceramic parts of the bottle is much easier and more efficient since ceramic does not absorb contaminants into its pores as will metallic surfaces.

[0007] According to another aspect of the invention there is provided an apparatus for retaining a well-fluid sample, the apparatus comprising a variable volume sample chamber having interior surfaces of a non-reactive material, the interior surfaces defining a cavity, the sample chamber comprising a tubular member, a piston slidingly engaged in the tubular member operable in response to fluid pressure within the sample chamber, a passageway defined in the sample chamber and adapted for providing fluid communication between the cavity and an area exterior the sample chamber, and a valve assembly operable for selectively opening and closing the passageway.

[0008] The non-reactive material is preferably ceramic. The tubular member preferably has a ceramic lining. Preferably, the piston is ceramic. Preferably, the passageway has a passageway lining of ceramic.

[0009] In an embodiment the sample chamber further comprises an endpiece sealingly disposed in the tubular member, the passageway being defined by the endpiece. The end piece is preferably ceramic.

[0010] In an embodiment, the valve assembly is a manually operable valve assembly comprising a valve element and a valve actuator for moving the valve element selectively between a closed position wherein the valve element seals the passageway and an open position wherein the passageway provides fluid communication between the cavity and an area exterior the sample chamber. The valve element is preferably ceramic. In this embodiment the sample chamber preferably forms part of a sample bottle.

[0011] In an embodiment, the passageway is defined in the tubular member.

[0012] In an embodiment, the valve assembly is a metering valve assembly operable in response to fluid pressure within the sample chamber, the metering valve assembly comprising a metering valve element having a sealing element attached thereto, the metering valve element slidingly disposed in the tubular member and moveable between a closed position wherein the sealing element seals the passageway and an open position wherein the passageway provides fluid communication between the cavity and an area exterior the sample chamber. The metering valve element is preferably ceramic. In this embodiment, the sample chamber preferably forms part of a sampler module.

[0013] According to another aspect of the invention there is provided a method for retaining a well-fluid sample in an apparatus having a sample chamberwith interior surfaces defining a cavity therein, the method comprising the steps of: placing the sample chamber proximate a well-fluid sample, the sample chamber comprising a tubular member, a piston slidingly engaged in the tubular member operable in response to fluid pressure within the sample chamber, a passageway defined in sample chamber and adapted for providing fluid communication between the cavity and an area exterior the sample chamber, and a valve assembly operable for selectively opening and closing the passageway; opening the passageway to provide fluid communication of the well-fluid sample between an area exterior the sample chamber and the cavity; transferring a well-fluid sample via the passageway from an area exterior the sample chamber to the cavity; and sealing the sample chamber by closing the passageway.

[0014] In an embodiment the step of opening the passageway (to provide .fluid communication of the well-fluid sample between an area exterior the sample chamber and the cavity) further comprises the step of manually opening the valve assembly by actuating a valve actuator to move a valve element from a closed position wherein the valve element seals the passageway to an open position wherein the passageway provides fluid communication between the cavity and an area exterior the sample chamber.

[0015] In an embodiment wherein the step of sealing the sample chamber by closing the passageway further comprises the step of manually closing the valve assembly by actuating the valve actuator to move the valve element from an open position wherein the passageway provides fluid communication between the cavity and an area exterior the sample chamber to a closed position wherein the valve element seals the passageway.

[0016] In another embodiment, the step of transferring a well-fluid sample via the passageway from an area exterior the sample chamber to the cavity further comprises the step of transferring the well-fluid sample from a sampler module to the cavity of the sample chamber.

[0017] In another embodiment, the valve assembly is a metering valve assembly operable in response to fluid pressure within the sample chamber, the metering valve assembly comprising a metering valve element having a sealing element attached thereto, the metering valve element being slidingly disposed in the tubular member and moveable between a closed position wherein the sealing element seals the passageway and an open position wherein the passageway provides fluid communication between the cavity and an area exterior the sample chamber, the step of sealing the sample chamber by closing the passageway further comprises the step of moving the metering valve element to the closed position.

[0018] Reference is now made to the accompanying drawings, in which:

Figure 1A-D comprise a longitudinal sectional view of a preferred embodiment of a sampler module of the present invention;

Figure 2A-B comprise a longitudinal sectional view of a preferred embodiment of a sample bottle of the present invention wherein the bottle is in an empty condition; and

Figure 3A-B comprise a longitudinal sectional view of a preferred embodiment of a sample bottle of the present invention wherein the bottle valves are in an open position.

[0019] Numeral references are employed to designate like parts throughout the various figures of the drawing. Terms such as "left", "right", "clockwise", "counterclockwise", "horizontal", "vertical", "up" and "down" when used in reference to the drawings, generally refer to orientation of the parts in the illustrated embodiment and not necessarily during use. The terms used herein are meant only to refer to relative positions and/or orientations, for convenience, and are not to be understood to be in any manner otherwise limiting. Further, dimensions specified herein are intended to provide examples and should not be considered limiting.

[0020] Presented are embodiments of a sample chamber exemplified in use in a sampler module and a sample bottle with non-reactive ceramic linings. The sampler module is seen in Figures 1A-D. Although only one embodiment of the sampler module is described in detail, it is understood that the invention may be practiced using any sampler module desired. The particular sampler module described herein is for use alone or as one of a plurality of sampler modules in a larger sampling tool. The sampler module is designed such that the sample chamber, which contains the well fluid sample, is entirely of non-reactive material, namely ceramic. The chamber lining, the piston, metering valves and the like are all of ceramic such that the well sample is entirely encased in a non-reactive lining. Similarly, the invention may be practiced on other particular embodiments of sampler modules or sampling tools, whether with single or multiple sampling chambers, by lining the sample chambers thereof with ceramic or other suitable material.

[0021] A sampler module 10 is seen in Figures 1A-D. The sampler module 10 is for use in a sampling tool as described in U.S. Patent 4,787,447 to Christensen which is hereby incorporated in its entirety by reference, or may be used in a sampling tool such as described in U.S. Patent 5,687,791 to Beck, et al. The sampler module 10 comprises a housing 12 having a drain cover 14, drain nipple 16, sample case 18, metering case 20, metering nipple 22 and air case 24.

[0022] Referring to Figures 1A and B, a drain cover 14 is connected to the drain nipple 16 at the threaded connection 30 and a seal 32 provides sealing engagement therebetween. The drain cover 14 has a threaded portion 34 extending therefrom for attachment to an adapter, hanger or connector of a sampling tool, as known in the art. The drain cover 14, as well as the nipples 16 and 22 and air case 24, have radially spaced spanner wrench indentations 36 for gripping by a spanner wrench or other appropriate tool for tightening and loosening the threaded connections between the housing parts.

[0023] The lower end of the drain nipple 16 is connected to the sample case 18 at the threaded connection 38 with a seal 40 providing sealing engagement therebetween. A longitudinal drain nipple passageway 42 is defined through the drain nipple 16. The passageway 42 is part of an autoclave system, as is known in the art.

[0024] The sample case 18, as seen in Figure 1A-B, is sealingly connected to the drain nipple 16 as described, and at the other end the sample case 18 is connected to the metering case 20 at the threaded connection 44 with a seal providing sealing engagement therebetween. The sample case 18 defines an elongated central cavity 48 therein bounded at its upper end by the lower face 50 of the drain nipple 16. The central cavity 48 of the sample case 18 is lined with a cylindrical sample case liner 52 of non-reactive material, preferably ceramic. Preferably the sample case liner 52 is pressure fit into the sample case 18. As seen in Figure 1B, a piston 54 is originally disposed at the lower end of the central cavity 48 in the sample case 18. Sealing engagement is provided between the piston 54 and the sample case 18 by a piston ring 56. The piston 54 is preferably of non-reactive material, namely ceramic. It will be thus seen that the portion of the central cavity 48 above the piston ring 56 is separated from the portion of the central cavity 48 below the piston ring 56. The portion of the central cavity 48 above the piston ring 56 defines an air chamber 60.

[0025] Preferably the piston 54 includes a recess 58 allowing for the disposal therein of the mixing ball 62. The mixing ball 62 is also preferably of non-reactive material such as ceramic.

[0026] Referring to Figures 1B-C, the metering case 20 defines an elongated metering central cavity 74 therein. A transverse port 76 provides communication between the metering central cavity 74 and the exterior of the sampler module housing 12, seen in Figure 1C. A countersink in the exterior wall of the metering case 20 forms a flat shoulder 78 which extends adjacent the port 74. The metering case 20 defines a first bore 80 in its upper end and a larger diameter second bore 82 in its lower end. The first bore 80 is lined with a metering case liner 84 made of non-reactive material, preferably ceramic. The ceramic liner 84 is preferably pressure fit into the first bore 80. The upper face 86 of the first bore 80 abuts the lower face 88 of the piston 54 as seen in Figure 1B.

[0027] Slidably disposed in the metering central cavity 74 is a metering valve 90. The metering valve 90 has a cylindrical first end 92 slidably disposed in the first bore 80 and an enlarged cylindrical second end 94 slidably disposed in the second bore 82. The metering valve 90 is preferably of non-reactive ceramic material.

[0028] The first end 92 of the metering valve 90 defines a longitudinal valve passageway 100 therein, forming an opening 102 at the upper face 96 of the first end 92 of the metering valve 90. The valve passageway 100 is in fluid communication, via one or more access ports 104, with an annular space 106 defined between the inner wall of the first bore 80 and the first end 92 of the metering valve 90. It will thus be seen that the valve passageway 100 provides fluid communication between the annular space 106 and the lower face 88 of the piston 54, and that the annular space 106 and valve passageway 100 provide fluid communication between the central cavity 48 in the sample case 18 and the central cavity 74 in the metering case 20. Above the access ports 104 a pair of spaced sealing rings 108 and 110 are carried on the exterior of the metering valve 90. The importance of the spacing of these sealing rings will be explained hereinafter. The metering valve 90 is held stationary in the metering cavity 74 by a plurality of shear pins 112 extending between the first end 92 of the metering valve 90 and the walls of the first bore 80.

[0029] The second end 94 has a valve ring 114 sealingly engaging the second bore 82 of the metering valve 90 below the port 76, seen in Figure.1C. It will be thus seen that the portion of the metering cavity 74 above the valve ring 114 is separated from the portion of the metering cavity 74 below the valve ring 114. The portion of the metering cavity 74 below the valve ring 114 defines a transfer fluid cavity 116 which may initially be filled with oil or any other desired transfer fluid as is known in the art. The second end 94 of the metering valve 90 has a cylindrical extension 98 extending therefrom into the second bore 82. It will be seen that an annular area differential is defined between the first and second ends 92 and 94 of the metering valve 90.

[0030] It is apparent that a fluid area is defined between the piston ring 56 of the piston 54 and the valve ring 114 of the metering valve 90. This area is the sample chamber 120 and is completely enclosed by non-reactive ceramic parts, namely, the ceramic liners 52 and 84, piston 54, mixing ball 62 and metering valve 90. It is in the ceramic lined sample chamber 120 that the well fluid sample is stored in a non-reactive environment.

[0031] Referring to Figures 1C-D, the lower end of the metering case 20 is connected to a metering nipple 22 at a threaded connection 124 and a seal 126 provides sealing engagement therebetween. At the juncture of the metering nipple 22 and the metering case 20, the nipple 22 defines a shoulder 128. The metering nipple bore 130, defined by the metering nipple 22, is of sufficient size to receive the extension 98 of the second end 94 of the metering valve 90. The metering nipple 22 defines a longitudinal passageway 132 therethrough, seen in Figure 1D, with orifice means 134 such a Visco-jet disposed across the lower end thereof. The Visco-jet is of a kind known in the art and has a small, precisely sized, orifice therethrough which provides restricted communication between the transfer fluid cavity 116 and the air case 24.

[0032] The lower end of the metering nipple 22 is connected to the air case 24 through a threaded connection 136 with a seal 138 providing sealing engagement therebetween. The air case 24 defines an elongated air cavity 140 therein which is in communication with the passageway 132 in the metering nipple 22. The air cavity 140 in the air case 24 has a closed lower end 142. The air case 24 has a downwardly extending stud portion 144 which is designed to extend into a hole on a die plate in a multi-chambered sampling apparatus such as is known in the art.

[0033] Turning to the operation of the sampler module 10, the components of the sampler module 10 are in the configuration shown in Figure 1A-D when the tool is run into a well bore. In this run-in position, the transfer fluid chamber 116 is filled with a viscous fluid such as oil. The air cavity 140 is initially filled with atmospheric air. Also initially empty is the central cavity 48 in the sample case 18.

[0034] Once at the desired well depth, the sampler module 10 is exposed to fluid from the well bore. It will be seen that the port 76 in the metering case 20 is in fluid communication with the exterior of the sampler module 10. Thus, as the sampler module 10 is exposed to the well environment, well fluid enters the port 76, flowing through the annular space 106 and longitudinal valve passageway 100, coming into contact with the lower face 88 of the piston 54, as best seen in Figure 1B. The fluid pressure forces the piston 54 upwardly in the central cavity 48 of the sample case 18, compressing the air in the central cavity 48 into the drain nipple 16. The piston 54 continues to move upwardly until it contacts the lower face 50 of the drain nipple 16, as best seen in Figure 1A, until the sample case 18 is filled with well sample fluid.

[0035] Fluid pressure also forces the metering valve 90 downwardly in the metering case 20, but the shear pins 112 maintain the metering valve 90 in place until the sample case 18 is filled. Once the sample case 18 is filled, pressure will build in the central cavity 48 and downward pressure on the metering valve 90 will increase. When a predeetermined critical pressure is reached, the shear pins 112 shear away and the metering valve 90 is free to move downwardly in the metering case 20. The oil present in the transfer fluid chamber 112 provides resistance to this downward motion of the metering valve 90, since the oil must past through the small orifice 134 in the Visco-jet before being discharged into the air cavity 140 in the air case 24. Eventually, the metering valve 90 moves all the way downwardly until it contacts the lower shoulder 128, best seen in Figure 1C, in the metering case 20 with the extension 98 slidingly engaged in the bore 130, thus displacing all of the oil out of the transfer fluid chamber 116 and compressing the air in the air cavity 140.

[0036] Once the metering valve 90 has reached its downwardmost position, the spaced sealing rings 108 and 110 close off the port 76 in the metering case 20. Thus, once the sample chamber 120 is completely filled with a sample fluid, the sampler module 10 is closed. Thus, a metering means is provided for automatically closing the sampler module 10 when a predetermined fluid volume is in the sample chamber 120.

[0037] Once the oil well tool is out of the well bore, the sample fluid in the sampler module may be drained. Alternately, the sampler module may act as the storage device. Because each sampler module is a self-contained unit, the sampler modules are easily transported and may be drained or stored where desired, such as in a laboratory.

[0038] The sampler module may be drained using methods known in the art. One example of a draining method without the use of mercury, commonly used in such operations, is described in U.S. Patent 5,423,229 to Schultz, et al. which is hereby incorporated by reference. The fluid may be drained into a sample bottle such as seen in Figures 2A-B and 3A-B.

[0039] The sample bottle presented here is by way of example only and is not intended to be limiting. The sample bottle comprises a sample chamber which is entirely comprised of non-reactive parts such that the fluid sample contained therein does not contact any reactive surfaces or materials. Preferably the non-reactive material is ceramic. The invention may be practiced in any sample bottle of any configuration and is not limited to the particular sample bottle described herein.

[0040] A sample bottle is seen in Figures 2A-B and 3A-B. The sample bottle 200 comprises a housing 202 having a first endcap 204, a sample case 206, and a second endcap 208. The first and second endcaps 206 and 208 are attached to the sample case 206 at threaded connections 210 and 212, respectively, and sealingly engaged to the sample case by seals 214 and 216, respectively.

[0041] The sample case 206 comprises a cylindrical sample case body 220 defining a sample cavity 222 therein. The sample cavity 222 is lined with a tubular ceramic liner 224. A piston 226, preferably of ceramic, is slidingly mounted in the liner 224 and sealingly engages the liner 224 at piston ring 228. The piston 226 thus divides the sample cavity 222 into a transfer fluid chamber 230 and a sample chamber 232, seen in Figures 3A-B, as will hereinafter be described. The piston 226 has a sample face 234 having a semi-spherical recess 236 defined therein. A mixing ball 238, preferably of ceramic, is disposed in the sample fluid chamber 232 of the sample cavity 222. The ceramic liner 224 is preferably pressure fit into the sample case body 220 and at opposite ends comprises flanges 240 and 242. The connection between the flanges 240 and 242 and the liner 224 define shoulders 244 and 246, respectively.

[0042] The first endcap 204 comprises an endcap body 250, a lock-nut assembly 252, a valve apparatus 254 and a ceramic insert 256. The endcap body includes a port 258 and tranverse port passageway 260. It is understood that the second endcap 208 has similar parts.

[0043] The ceramic insert 256, preferably pressure fit into the endcap body 250, comprises an end portion 262 having an end face 264 with a semi-spherical recess 266 defined therein, an intermediate portion 268 and a tip portion 270 having a tip face 272. An insert passageway 274 is defined through the insert 256 and has a tapered valve seat 276 opening at the tip face 272. The recess 266 of the insert 256 is aligned with the recess 236 of the piston 226 to create a spherical opening for disposal of the mixing ball 238 when the piston 226 is positioned such that the sample face 234 abuts the end face 264 of the insert, as seen in Figure 2A-B.

[0044] A valve apparatus 254 having a valve actuator 282, a valve chamber 284 and a valve dart 286, is disposed in the first endcap 204 and is attached to the endcap by a threaded connection 288. Seal 290 sealingly engages the endcap 204 and valve apparatus 254. The valve chamber 284 is defined by the valve apparatus 254 and provides fluid communication between the insert passageway 274 and the port passageway 260 when the valve is in the open position seen in Figure 3B. The valve apparatus may be longitudinally moved between the open position, seen in Figure 3B, and the closed position, seen in Figure 3A, by rotating the valve apparatus upon the threaded connection 288. The apparatus may be rotated by using the appropriate tool inserted into the valve socket 292 as is known in the art. In the closed position, the tapered valve dart 286, preferably made of ceramic, is in sealing engagement with the tapered valve seat 276 of the ceramic insert. The valves on each end of the sample bottle 200 are area-balanced so there is no compression of fluid when the valves are opened or closed.

[0045] The port 258, the port passageway 260, the valve chamber 284, and the insert passageway 274 combine to provide fluid communication between the area exterior the sample bottle 200 and the sample case cavity 222 when the valve apparatus is in the open position seen in Figure 3B. In the closed position of Figure 3A, the valve apparatus 254 prevents fluid communication and seals the sample cavity 222 and insert passageway 274 from the port passageway 260 and exterior of the bottle.

[0046] It is apparent that the sample bottle 200, when filled as seen in Figure 3A-B, comprises a sample chamber 232 completely comprised of non-reactive ceramic parts. The ceramic liner 224, piston 226, mixing ball 238, insert and valve dart 286 completely enclose the fluid sample. The sample is not exposed to reactive materials and so the sample is not contaminated and does not react effecting the purity of the sample.

[0047] For purposes of discussion, the lock-nut assembly 252 of the first endcap 204 will be described, but it is understood that the second endcap 208 has similar parts. To ensure a proper contact pressure between the ceramic liner 224 of the sample case 206 and the ceramic insert 256 at shoulder 244, a lock-nut 300 is shear-pinned onto the body of the endcap so that only a certain amount of torque may be applied to the lock-nut 300 before the shear pins 302 shear. No increase in contact pressure between the ceramic parts can be made by further turning of the lock-nut 300. Explained another way, the lock-nut 300 is attached to the endcap body 250 by a threaded connection 304. A plurality of radially spaced shear pins 302 maintain the lock-nut 300 and endcap body 250 in stationary relative positions. The shear pins 302 are designed to shear or break when a pre-selected torque is applied to the lock-nut 300. The endcap 204 is screwed onto the sample case 206 using the lock-nut 300. As the lock-nut 300 is turned, the endcap body 250 is threadedly connected to the sample case 206. The endcap body 250 is rotated until the end face 264 of the ceramic insert 256 is seated tightly against the shoulder 244, thus creating a ceramic-to-ceramic seal. Placing continued torque on the lock-nut 300 shears the shear pins 302 such that the lock-nut 300 is free to turn in relation to the endcap body 250 about the threaded connection 304. That is, the lock-nut 300 continues to turn about its threaded connection 304 with the endcap body 250 while the endcap body 250 ceases to turn about its threaded connection 210 with the sample case 206. The torque necessary to shear the shear pins 302 is selected such that tightening the lock-nut 300 and endcap body 250 will not result in damaging or cracking of the ceramic insert 256 or ceramic liner 224.

[0048] The second endcap 208 is similarly attached to the sample case 206 at threaded connection 212 and sealingly engaged at seal 216. The ceramic liner 224 of the sample case 206 and the ceramic insert 296 of the endcap 208 fit together at shoulder 246 in a ceramic-to-ceramic seal. The second endcap 208 is of similar construction to the first endcap 204 for ease of manufacture, but it is understood that the second endcap 208 may take another design and not depart from the spirit of the invention.

[0049] Filling of the sample bottle 200 will now be discussed. In Figures 2A-B, the sample bottle 200 is in condition to receive a well fluid sample, such as from the sampler module 10. Initially the piston 226 is in the position seen in Figure 2A, such that the sample face 234 of the piston 226 abuts the end face 264 of the insert 256.

[0050] The mixing ball 238 is disposed in the spherical opening defined by the semi-spherical recesses 236 and 266. Both the valve apparatus 254 and 294 are closed. A transfer fluid, such as water, glycol, nitrogen or other material as is known in the art, is disposed in the transfer fluid chamber 230.

[0051] Drain collars, nipples and lines, with appropriate valving, are attached to the sample bottle 200, as is known in the art. The drain lines and valving connect the sample bottle 200 to the sampler module 10 or other source which has a well fluid sample disposed therein.

[0052] The valve apparatus 254 and 294 are moved to their open positions, as seen in Figures 3A-B, to provide fluid communication between the cavity 222 and the drain lines attached to the ports 258 and 356. From the drain lines, the fluid sample enters the first encap port 258, flows through the port passageway 260, the valve chamber 284 and the insert passageway 274, and into the sample chamber 232 coming into contact with the sample face 234 of the piston 226. The fluid pressure forces the piston 226 toward the second endcap 208 enlarging the sample fluid chamber 232 and contracting the transfer fluid chamber 230. The transfer fluid in the transfer fluid chamber 230 provides resistance to the motion of the piston 226. This resistance may be regulated by the valve and drain line assembly attached to the second endcap port 306 as the transfer fluid is drained out of the transfer fluid chamber 230. Eventually, the piston 226 moves all the way through the cavity 222 until it contacts the end face 308 of the insert 296, thus displacing the transfer fluid and filling the sample chamber 232 with sample fluid.

[0053] Once the sample chamber 232 is filled with sample fluid, the valve apparatus 254 and 294 are moved to the closed position, seen in Figures 2A-B, sealing off the sample bottle 200. The sample bottle 200 is self-contained and is easily transportable. The sample bottle may be stored at any desired location for any length of time. Because the bottle is ceramic lined and all of the portions of the bottle which are in contact with the fluid sample are of non-reactive material, such as ceramic, the fluid sample will not corrode or react with the sample bottle thereby contaminating the fluid sample. Further, the bottle is easily cleansed for later reuse as the ceramic parts do not absorb the sample as metallic parts are prone to do.

[0054] It will be appreciated that the invention described above may be modified.

Claims

1. An apparatus for retaining a well-fluid sample, the apparatus comprising: a variable volume sample chamber having interior surfaces of a non-reactive material, the interior surfaces defining a cavity (48,222), the sample chamber comprising a tubular member, a piston (54, 226) slidingly engaged in the tubular member operable in response to fluid pressure within the sample chamber, a passageway (76, 260) defined in the sample chamber and adapted for providing fluid communication between the cavity (48, 222) and an area exterior the sample chamber, and a valve assembly (90, 254) operable for selectively opening the closing the passageway.

2. Apparatus according to claim 1, wherein the non-reactive material is ceramic.

3. Apparatus according to claim 1 or 2, wherein the sample chamber further comprises an endpiece (204) sealingly disposed in the tubular member, the passageway defined by the endpiece (204).

4. Apparatus according to claim 1, 2 or 3, wherein the valve assembly (254) is a manually operable valve assembly (254) comprising a valve element (286) and a valve actuator (282) for moving the valve element (286) selectively between a closed position wherein the valve element (286) seals the passageway (260) and an open position wherein the passageway (260) provides fluid communication between the cavity and an area exterior the sample chamber.

5. Apparatus according to claim 1, 2 or 3, wherein the valve assembly (90) is a metering valve assembly (90) operable in response to fluid pressure within the sample chamber, the metering valve assembly (90) comprising a metering valve element (92) having a sealing element (108,110) attached thereto, the metering valve element (92) slidingly disposed in the tubular member and moveable between a closed position wherein the sealing element (108, 110) seals the passageway (76) and an open position wherein the passageway (76) provides fluid communication between the cavity and an area exterior the sample chamber.

6. A method for retaining a well-fluid sample in an apparatus having a sample chamber with interior surfaces defining a cavity (48,222) therein, the method of comprising the steps of: placing the sample chamber proximate a well-fluid sample, the sample chamber comprising a tubular member, a piston (54, 226) slidingly engaged in the tubular member operable in response to fluid pressure within the sample chamber, a passageway (76, 260) defined in the sample chamber and adapted for providing fluid communication between the cavity (48, 222), and an area exterior the sample chamber, and a valve assembly (90, 254) operable for selectively opening and closing the passageway (76, 260); opening the passageway (76, 260) to provide fluid communication of the well-fluid sample between an area exterior the sample chamber and the cavity (48, 222); transferring a well-fluid sample via the passageway (76, 260) from an area exterior the sample chamber to the cavity (48, 222); and sealing the sample chamber by closing the passageway.

7. A method according to claim 6, wherein the non-reactive material is ceramic.

8. A method according to claim 6 or 7, wherein the sample chamber further comprises an endpiece (204) sealingly disposed in the tubular member, the passageway (260) defined by the endpiece (204).

9. A method according to claim 6, 7 or 8, wherein the step of opening the passageway (26) further comprises the step of manually opening the valve assembly (254) by actuating a valve actuator (282) to move a valve element (286) from a closed position wherein the valve element (286) seals the passageway (260) to an open position wherein passageway (260) provides fluid communication between the cavity (222) and an area exterior the sample chamber.

10. A method according to claim 6, 7, 8 or 9 wherein the passageway (76, 260) is defined in the tubular member.

Drawing