US3530933A - Formation-sampling apparatus - Google Patents

Description

United States Patent [72] Inventor Frank R. Whitten Houston, Texas [21] Appl. No. 812,726 [22] Filed April 2, 1969 [45] Patented Sept. 29, 1970 [73] Assignee Schlumberger Technology Corporation New York, New York a corporation of Texas [54] FORMATION-SAMPLING APPARATUS 33 Claims, 11 Drawing Figs.

[52] [1.5. CI. 166/100, 166/55.l [5i] lnt.Cl E2lb 49/00 [50] Field of Search 166/ 100, 55.1; 175/452 [56] References Cited UNITED STATES PATENTS 2,612,346 9/ 1952 Nelson 166/ l00X 2,903,068 9/ 1959 Lebourg 166/ 100x 3,295,615 1/1967 Brieger et a1. 166/ l 00X 3,352,361 11/1967 Urbanosky 3,385,364 5/1968 Whitten Primary Examiner- David H. Brown AttorneysErnest R. Archambeau, 1%., William J. Beard,

Donald H. Fidler, David L. Moseley, Edward M. Roney and William R. Sherman ABSTRACT: In each of the several embodiments of the new and improved fluid-sampling apparatus disclosed herein, sample-admitting means adapted to be selectively extended therefrom include an annular sealing pad operatively arranged around the forward end of a tubular sampling member so that, upon contacting a well bore surface, the pad will make firm sealing engagement therewith. Means are provided for delaying the establishment of flow communication between a sampie-collecting system in the apparatus and an earth formation being tested until the sample-admitting means have been extended. Means are uniquely arranged in the sampling member for regulating the flow of fluid samples as well as for limiting the entrance of mudcake and unconsolidated formationmaterials that might otherwise plug the sampling apparatus or disrupt the sealing engagement of the sealing pad.

Patented Sept. 29, 1910 I V 3,530,933

Sheet I. of '7 Frcznk Whitten KINVENTOR f A TQRNEY 25 s. 24 mi Patented Se t. 29,1970 3,530,933

Sheet 2 of? Fmbk 'RuWhi'tten INVENTOR ATIORNE'Y Patented Sept. 29,1970 3,530,933

Sheet 3 of? FIG. 4

Frank R. Whitten INVENTOR ATTORNEY v Patented Sept. 29,1970 I :i3 5 30,933

Sheet of! w mi:

4a Frd-nik R Whitteh INVENTOR mm a j ATTORNEY Patented Sept. 29, 1970 3,530,933

Sheet, of 7' FIG. 6

Frqhk R. Whitten 'INVENTOR f .EYATYTORNEY Patented Sept. 29, 1970 I 3,530,933

Sheet 6 of 7 Ran R, Whitten 1 INVENTOR' ATTORNEY Patented Sept. 29', 1970 '2 3,530,933

Sheet Y of 7 FIG. 9

Fra hk R. Whitten v {NVENTOR A'rTbRA/Ey I FORMATION-SAMPLING APPARATUS Although the new and improved fluid-sampling tools disclosed in U.S. Pat. No. 3,385,364 have generally been highly successful, there have nevertheless been occasions where at least one of the several testing units on such a too] did not effect satisfactory fluid communication with an earth formation to obtain a fluid sample therefrom. For example, in some instances, one or more of the wall-engaging sealing pads on these tools may not make a satisfactory sealing engagement with the borehole wall where the formations being investigated are relatively unconsolidated. The problem here is attributed to the inability of the pad members to remain in sealing engagement with the borehole wall since such unconsolidated formation materials will tend to be rapidly eroded away from under the face of the pad as a fluid sample is being withdrawn.

To reduce the rate at which these unconsolidated formation materials are washed away, these aforementioned fluid-sampling tools have been arranged to regulate the flow rate at which fluid samples are admitted. In one manner of accomplishing this, a slidable piston is operatively arranged within the sample-receiving chamber of each testing unit to slowly displace a quantity of water contained therein through an orifice into an adjacent atmospheric chamber as the pressured fluid sample is admitted into the sample chamber on the opposite side of the piston.

Although this and other measures have improved the odds of obtaining fluid samples from unconsolidated formations, there are still some problems arising in the use of such apparatus. For example, where the flow rate at which a sample is obtained must be greatly limited, the fluid-sampling apparatus often must be held in position for perhaps an hour. Such long waits generally make it necessary to continually reciprocate the suspension cable to prevent it from becoming stuck in the well as by differential sticking or key-seating. Moreover, extended testing cycles will expend valuable rig time as well as reduce the number of operations that can be conducted during an allotted time. It will also be recognized that the overall length of each testing unit must be increased simply to accommodate the volume of water or so-callcd water cushion" carried in the sample chamber.

Accordingly, it is an object of the present invention to provide new and improved fluid-sampling apparatus operatively arranged for reliably effecting fluid communication with various types of borehole surfaces and formation materials.

Another object of the present invention is to provide new and improved fluid-sampling apparatus that is capable of taking fluid samples at rapid flow rates without disrupting fluid communication with the formation.

Still another object of the present invention is to provide new and improved fluid-sampling apparatus that does not necessarily require a space-consuming water cushion in its sample-receiving chamber.

These and other objects of the present invention are attained by new and improved fluid-sampling apparatus having sample-admitting means including a tubular sampling member adapted to be placed into fluid communication with a selected surface of a well bore such as a borehole wall. To assure reliable fluid communication of the tubular member with the borehole wall, packing means are operatively mounted around the tubular member and adapted to sealingly engage the borehole wall for isolating the selected surface. The sampleadmitting means further include means for limiting the entrance of unconsolidated formation particles as well as mudcake from the borehole wall or other unwanted debris or fluent matter that might otherwise tend to impede or halt the fluid-sampling operation.

The novel features of the present invention are set forth with particularity in the appended claims. The invention, together with further objects and advantages thereof, may be best understood by way of the following exemplary apparatus employing the principles of the invention as illustrated in the accompanying drawings, in which:

FIG. 1 depicts fluid-sampling apparatus of the present invention as it might appear within a borehole; v

FIG. 2 is a somewhat schematic representation of one preferred embodiment of the apparatus depicted in FIG. 1;

FIGS. 3-5 are views similar to FIG. 2 depicting the apparatus at selected sequential stages of a typical testing operation; a

FIG. 6 depicts an alternative embodiment of fluid-sampling apparatus also employing the principles of the present invention;

FIGS. 7 and 8 are'partial views similar to FIGS. 3 and 4 but respectively illustrate the progressive positions of various elements of the preferred embodiment shown in FIG. 6 during the course of a typical sampling operation;

FIG. 9 illustrates still another embodiment of fluid-sampling apparatus arranged in accordance with the present invention;

FIG. 10 illustrates the embodiment of FIG. 9 during a typical sampling operation; and

FIG. 11 shows an alternative arrangement for obtaining an increased range of lateral extension for any of the various embodiments of the sample-admitting means respectively depicted in FIGS. 2, 6 and 9.

Turning now to FIG. 1, fluid-sampling apparatus 20 incorporating the principles of the present invention isshown suspended from a multi-conductor cable 21 in a well bore such as a borehole 22 containing a well control fluid. The apparatus 20 has been positioned adjacent a particular formation interval 23 for collecting a sample of producible fluids from that formation. The cable 21 is spooled in the usual manner from a winch 24 at the earth s surface, with some ofits conductors being connected to a switch 25 for selective connection to a power source 26 and others being connected to typical indicating and recording apparatus 27. To permita number of tests to be made during a single trip into the borehole 22, the fluid-sampling apparatus 20 is comprised of a corresponding number of tandemly-arranged sampling units, as at 28, that are each capable of independent operation and respectively include extendible sample-admitting means-.29 (or 100 and 200) spatially disposed along one side of the sampling apparatus. As illustrated in FIG. 1, one of the sample-admitting means 29 (or 100 and 200) has been extended into fluid communication with the exposed face of the formation 23 for obtaining a sample of connate fluids therefrom.

. As illustrated schematically in FIGS. 2-5, each testing unit 28 of the fluid-sampling apparatus 20 is basically comprised of the selectively-extendible sample-admitting means 29 for obtaining samples of formation fluids, sample-collecting means 30 for recovering such samples, and selectively-operable means 31 for retracting the sample-admitting means. To operate these several means 29-31, a number of selectivelyoperable, normally-closed valves 32-36 are operativelyarranged for selectively admitting well control fluids from the borehole 22 to their respectively associated pressure-responsive means to utilize the hydrostatic pressure of the boreholefluids as a source of motivating power.

Generally speaking, the several means 3036 of the apparatus of the present invention are arranged similarly to their respective counterparts shown in US. Pat. No. 3,385,364 to employ the hydrostatic pressure of the fluids in the borehole 22 for operation of the apparatus 20. Thus, as will subsequently be described, the valves 32-36 are normally closed; and as the valves are successively opened in response to electrical signals from the surface, the well control fluids are selectively directed to the particular pressure-responsive means 29 (or and 200) as well as 30 and 31 that each valve is controlling. Accordingly, these several means 30-36 are illustrated only schematically in the drawings and need to be described only as is necessary to understand their functions in the new and improved tool 20 of the present invention.

The sample-collecting means 30 include a sample receiver which, as illustrated, may in some circumstances be divided into upper and lower chambers 37 and 38 separated from one another by a partition 39 having a flow restriction or orifice 40,

therein. When these dual chambers 37 and 38 and interconnecting orifice 40 are employed, a liquid cushion 41 (such as water) is initially disposed in the lower chamber 38 and isolated therein by a floating piston 42. Since the upper chamber 37 is initially empty and at a low or atmospheric pressure, formation fluids (at whatever the formation pressure is) entering the sample chamber 38 will move the piston 42 toward the partition 39 at a rate regulated by the discharge of the water cushion 41 through the orifice 40. As previously discussed, however, elimination of the water cushion 41 will reduce the overall length of each testing unit 28. Thus, as will subsequently be appreciated, the success of the present invention does not depend upon the water cushion 41 and it has been illustrated here only to show that it may be used, if desired, with the new and improved formation-sampling apparatus of the present invention.

To conduct fluid samples from the sample-admitting means 29 (or 100 and 200) to the sample-collecting means 30, passage means are included such as a fluid passage 43 in the body 44 of the apparatus 20 that is serially divided by a pair of pressure-actuated valves 45 and 46 operatively arranged so that the first valve 45 is selectively opened to admit a fluid sample to the sample chamber 38 and the second valve 46 is selectively closed to trap the sample therein. A pressure transducer 47 is connected to an intermediate portion of the passage 43 between the valves 45 and 46 and adapted to provide representative signals that are transmitted through the cable 21 to the indicating and recording apparatus 27 at the surface.

As fully described in the aforementioned patent, the retracting means 31 are comprised of one or more pressure-developing pistons 48 operatively arranged in a hydraulic chamber 49 that is coupled by way of an outlet passage 50 and a normally closed pressure-actuated valve 51 to an emergency release apparatus 52 and the sample-admitting means 29 (or 100 and 200). As will be later explained, whenever the hydraulic valve 51 is opened, a pressured hydraulic fluid is operatively employed for retracting the sample-admitting means 29 (or 100 and 200). It will be understood, of course, that so long as the hydraulic valve 51 remains closed, the hydraulic pressure developed by the pressure-developing pistons 48 will be inoperative. To actuate the hydraulic valve 51, one, or preferably two, control valves, as at 35 and 36, are arranged for selective operation in response to signals from the surface. By arranging the control valves 35 and 36 in parallel, should one valve fail to open, the other control valve will provide a second opportunity for opening the hydraulic valve 51.

Should some malfunction in the retracting means 31 prevent the retraction of the sample-admitting means 29 (or 100 and 200), the emergency release apparatus 52 is arranged to selectively admit the borehole fluids into the apparatus 20 for equalizing the pressure differential across the sample-admitting means. As described in US Pat. No. 3,385,364, the emergency release apparatus 52 is associated with an extendible wall-engaging piston member 53 that (upon opening ofthe control valve 34) is adapted to displace the tool body 44 away from one wall of the borehole 22 as the sample-admitting means 29 (or 100 and 200) are beingextended in the opposite direction toward the other wall of the borehole. Ordinarily upon opening of the hydraulic valve 51, the wall-engaging piston 53 will be retracted along with the sample-admitting means 29 (or 100 and 200). However, should there be some malfunction, borehole fluids will be admitted into the passage 50 once the outer end of the extendible wall-engaging member 53 is broken to open an enclosed axial passage 54 therein.

In the sample-admitting means 29 shown in FIG. 2, an elongated tubular member 55 is slidably disposed for longitudinal movement within a lateral bore 56 formed in the body 44 of the testing unit 28 and fluidly sealed in relation thereto as by an O-ring 57 coaxially mounted around the forward portion of the lateral bore. The sample-admitting means 29 further include an inner tubular member 58 that is coaxially disposed within the outer tubular member 55 and adapted for longitudinal movement therein from the retracted or rearward position depicted in FIG. 2 to an extended or forward position (FIG. 4) for securing fluid samples. The inner fluid-sampling member 58 is fluidly sealed in relation to the outer tubular member 55 as by an O-ring 59 mounted around an enlargeddiameter shoulder 60 on the rear portion of the inner member and an O-ring 61 arranged within the forward portion of the outer member, with these longitudinally-spaced O-rings defining an elongated annular space 62 between these tubular members that is at atmospheric pressure.

In the preferred arrangement of the sample-admitting means 29, the rearward end of the outer tubular member 55 carries a tubular body 63 that is fluidly sealed therein, as by an O-ring 64. To secure the tubular body 63 against rearward and forward movement in relation to the outer member 55, as shown generally at 65, the rearward end of the tubular body is slightly enlarged and secured within a complementary counterbore formed in the rearward end of the outer tubular member by a snap ring. For reasons that will subsequently become apparent, a third and still smaller elongated tubular member 66 having a reduced-diameter or spooled intermediate portion between longitudinally-spaced enlarged diameter shoulders 67 and 68 thereon is slidably telescoped within the coincidentally-aligned axial bores 69 and 70 of the inner tubular member 58 and tubular body 63.

The innermost tubular member 66 is arranged so that in its initial position, its longitudinally-spaced shoulders 67 and 68 are respectively positioned within the axial bores 69 and 70 and fluidly sealed in relation to the inner tubular member 58 and tubular body 63 as by O- rings 71 and 72. The forward end of the slidable tubular member 66 is closed as by a transverse wall 73; and the rearward portion of this tubular member is extended through the rear of the tubular body 63 and fluidly sealed in relation thereto as by an O-ring 74. The innermost member 66 is secured against forward movement in relation to the other tubular members 55 and 58 as by an outwardly directed shoulder or flange 75 thereon which is normally abutted against the rear face of the tubular body 63. To provide fluid communication between the axial bore 69 of the tubular sampling member 58 and the axial bore 76 of the innermost tubular member 66, the forward portion of the innermost member is slotted or drilled, as at 77, ahead of its forward enlarged shoulder 67 and these apertures are covered with a suitable filtering member such as a meshed screen 78 or other porous material.

To selectively extend the sample-admitting means 29, piston means, such as an enlarged annular piston member 79 having a tubular forward extension, are slidably disposed in an enlarged annular bore 80 formed coaxially in the tool body 44 around the lateral bore 56 and coupled, as at 81, to the forward end of the outer tubular member 55. O-rings, as at 82 and 83, are appropriately arranged around and within the piston member 79 for fluidly sealing the piston member within the enlarged coaxial bore 80; and an O-ring 84 is coaxially mounted around the forward end of the enlarged bore for fluidly sealing the tubular extension of the piston in relation to the tool body 44 and defining an enclosed annular space 85 ahead of the piston that is initially at atmospheric pressure. Accordingly, it will be appreciated that upon introduction of borehole fluids through a passage 86 into the rear of the enlarged annular bore 80 behind the piston member 79, the sample-admitting means 29 will be urged forwardly in relation to the tool body 44 and toward an adjacent wall of the borehole 22.

Sealing means, such as an annular elastomeric sealing pad 87 arranged on the front ofa rigid backing plate 88, are operatively mounted on the forward end of the outer tubular member 55 and adapted to be moved thereby into sealing engagement with a borehole wall. To enable the sealing pad 87 to better conform to the contour of an irregular borehole wall, the rigid backup plate 88 is movably and sealingly coupled to a spherically-shaped enlarged head 89 on the forward end of the outer tubular member 55. Thus, upon forward movement of the sample-admitting means 29, the sealing pad 87 will be free to swivel in relation to the enlarged head 89 and assume a position where the forward face of the pad is at least substantially parallel to the particular surface of the borehole wall it is contacting. Once the elastomeric pad 87 is urged against a borehole wall, the substantial forces urging it into sealing engagement therewith will isolate the adjacent surface of the wall and the central opening 90 through the pad from the borehole fluids.

To obtain a fluid sample from a selected formation, the formation-sampling apparatus is positioned as shown in FIG. 1 in the borehole 22 opposite the formation 23. At this point, however, the various elements of the apparatus 20 will still be in their initial positions substantially as shown in FIG. 2. Then (as best seen in FIG. 3), once the apparatus 20 is in position, the control valve 34 is selectively opened to admit well control fluids into the body passages 86 and 91 for simultaneously extending the piston 79 and the extendible wall-engaging member 53 in opposite lateral directions. Once the outer end of the extendible wall-engaging member 53 (or, perhaps, the rear face of the apparatus 20) engages the rear wall of the borehole 22, continued forward movement of the piston member 79 will firmly urge the sealing member 87 into sealing engagement against the adjacent surface of the borehole with a substantial force that is equal to the hydrostatic pressure of the well control fluids multiplied by the cross-sectional area of the piston 79 through O- rings 82 and 84. As previously mentioned, the swivel connection 89 allows the sealing member 87 to assume an effective position in relation to the configuration of the borehole wall.

It will, of course, be appreciated that the extension of the piston 79 will initially advance the telescoped tubular members 55, 58 and 66 simultaneously. However, as will subsequently be discussed, the sample-admitting means 29 are operatively arranged to delay forward movement of the inner tubular member 58 in relation to the outer tubular member 55 until the sealing member 87 has been extended for establishing sealing engagement with the borehole wall. To accomplish this selectively delayed but positive extension of the inner sampling member 58 in relation to the outer sampling member 55, the sample-admitting means 29 are so arranged that as long as the outer member is fully retracted within the housing bore 56, the flanged end 75 of the innermost member 66 is against the rear wall of the housing bore and cannot be shifted rearwardly in relation to the inner and outer members by the hydrostatic pressure acting rearwardly on the effective area defined between the O- rings 71 and 74. Moreover, so long as the O-ring 71 on the forward shoulder 67 of the innermost tubular member 66 is sealingly engaged within the axial bore 69 of the inner sampling member 58, the hydrostatic pressure of the borehole fluids will be acting rearwardly on the inner member to urge it against the forward face of the tubular body 63.

Accordingly, the inner sampling member 58 is prevented from moving forwardly until the piston 79 is extended for placing the sample-admitting means 29 into fluid communication with the formation 23. Once, however, the sample-admitting means 29 move forwardly and the rear flange 75 of the slidable tubular member 66 is displaced from the rear wall of the-housing bore 56, the rearwardly-acting pressure forces on the slidable member will begin urging it rearwardly in relation to the advancing tubular members 55 and 58 and the tubular body 63. It will,'therefore, be recognized that once the innermost tubular member 66 moves sufficiently rearwardly in relation to the outer and inner tubular members 55 and 58 so as to withdraw the O-ring 71 from sealing engagement within the inner bore 69 of the inner tubular member 58, the intermediate spooled portion of the innermost member functions (in conjunction with the members 58 and 63) as a valve for selectively admitting borehole fluids into the previouslyclosed annular space 92 between the O- rings 59 and 64 and the O- rings 71 and 72. Once the borehole fluids enter this space 92, their hydrostatic pressure will, thereafter, be urging the inner tubular member 58 forwardly in relation to the outer tubular member 55 with a substantial force since the annular bore space 62 between the O- rings 59 and 61 is at atmospheric pressure.

Accordingly, as previously mentioned, the sample-admitting means 29 of the present invention further include means for selectively delaying this forward movement of the inner tubular member 58 so as to enable the sealing member 87 to first be sealingly disposed against the borehole wall before the inner tubular member is extended. In the preferred manner of accomplishing this, the annular space 93 (FIG. 2) defined in the axial bore 70 of the tubular body 63 and between the O- rings 72 and 74 is initially filled with a viscous fluid or some suitable fluent material such as a silicone grease or other deformable plastic materials, and a small flow passage 94 (H6. 3) is formed in the shoulder 68 for bypassing the O- ring 72 to provide restricted communication between this fluid-filled annular space and the space 95 around the spooled portion of the member 66 defined between the O- rings 71 and 72. Thus, the time required for the innermost tubular member 66 to shift rearwardly from its initial position (FIG. 2). to its final position (FIG. 3) will be governed by the time required for the effective force of the hydrostatic pressure acting rearwardly on the tubular member 66 to displace the viscous fluid from the space 93, through the restricted passage 94, and into the atmospheric space 95.

It will, of course, be understood that even upon application of a substantial forwardly directed pressure force on the piston portion 60 of the sampling tube 58 as illustrated in FIG. 3, the forward end of the tubular sampling member can penetrate the adjacent formation (as at 23) only so far as is permitted by the nature of the particular formation materials. Thus, should the formation 23 be fairly competent, the forward end of the tube 58 will, most likely, still be incapable of making a significant penetration into the formation. Thus, it is presumed that, at best, this forwardly acting pressure force will probably cause the forward end of the sampling tube 58 to penetrate only the so-called mudcake(as at 96) that typically lines the wall of a borehole traversing a potentially-producible earth.

formation, as at 23.

As depicted in FIG. 3, forward movement of the piston 79 upon opening of the control valve 34 will, therefore, successively extend and compress the sealing member 87 into sealing engagement with the mudcake-lined face of the formation 23 and then drive the tubular sampling member 58 forwardly through the now isolated central opening 90 into the mudcake Accordingly, in keeping with the objects of the invention, as-

the forward end of the sampling tube 58 penetrates the mudcake (as at 96) on the borehole wall, the resulting cylindrical plug of mudcake driven into the nose of the tube will be forcibly driven (by formation pressure) rearwardly into the enlarged annular space 92 to the rear of the piston 60 and around the rearward portion of the filtering screen 78.-

Similarly, should the tube 58 penetrate an unconsolidated producible formation, any formation particles carried into the sample-admitting means 29 by the flow of connate fluids will; also be received within the momentarily-voided annular space 92. Ultimately, however, formation fluids as well as the mudcake plug (and possibly at least some loosened formation particles) will have filled the voided annular space 92 to equalize the momentary pressure differential created by the initial forward movement of the sample-admitting means 29. Thus,

once the initial forward movement of the sampling tube 58' is halted, any plug of the mudcake 96 that would otherwise have portion of the lateral blocked either the inner bore 69 of the sampling tube or the filtering screen 78 will be safely disposed in the annular space 92 to the rear of the screen. Similarly, should there also be any formation materials displaced after the plug of mudcake is removed, these too will be disposed behind the mudcake plug in the forward portion of the annular space 92. Although the displaced mudcake plug and perhaps some, if any, of such initially displaced formation materials will be rather impermeable, at least a substantial portion of the forward end of the screen 78 will be free of foreign matter so as to not materially impede the subsequent flow of formation fluids through the filtering screen. It will be appreciated, of course, that the screen 78 is selectively sized to strain out such loosened formation particles. It should also be recognized that the selectively limited volume of the momentarily voided space 92 will be correspondingly related to the forward travel of the sampling tube 58. Thus, the forward position of the sampling tube 58 illustrated in FIG. 3 will be determined by the quantity of displaced mudcake and formation particles.

Accordingly, at this point in the operating cycle of the tool 20, the sample-admitting means 29 will have established fluid communication with the formation, as at 23, being tested before a fluid sample is taken. By selectively displacing the plug of mudcake as well as any formation particles that may initially enter the sample-admitting means 29 into the rearward space 92, at least a substantial portion of the filtering screen 78 will be available for straining fluid samples upon opening of the flow line valve 45. Thus, as seen in FIG. 4, a formation fluid sample is obtained by simply opening the flow line valve 45; and then, once the transducer 47 indicates that the sample chamber 38 is filled, closing the seal valve 46.

Once the flow line valve 45 is opened, there will be a substantial pressure differential between the formation pressure and the low or atmospheric pressure in the upper chamber 37 that will promote flow of the connate fluids into the sampleadmitting means 29 at a regulated rate as, for example, might be determined by the orifice 40. If, for example, the formation 23 is fairly competent, there will be little or no erosion of the formation materials and the sampling tube 58 will remain in about the same relative position shown in FIG. 3. On the other hand, should the formation 23 be unconsolidated, it will be recognized that unless the space 92 were previously filled, the connate fluids will again carry a selectively limited quantity of formation particles into the sampling tube 58 once the flow line valve 45 is opened.

Accordingly, as illustrated in FIG. 4, these loosened formation particles will rapidly fill the volume remaining in the selectively limited annular space 92 as the connate fluids pass on through the filtering screen 78 and into the sample chamber 38. At the same time, as these loosened particles move into the sampling tube 58, the formation pressure acting forwardly on the piston member 60 will simultaneously advance the sampling tube a corresponding distance into the formation 23. The limited volume of the annular space 92 and inner bore 69 of the sampling tube 58 will, however, be quickly filled with a packed column of the loosened particles. Once this occurs, it will be appreciated that no further movement of loosened formation materials can take place since the packed column will be fully supported within the sample-admitting means 29. Thereafter, only connate fluids can flow into the sample-admitting means 29 with this packed column of formation materials serving as a filtering media that is well supported by the screen 78. It will be recognized, therefore, that once the erosion of formation materials is halted, the sealing member 87 will be capable of retaining effective sealing engagement against the borehole wall for the entire testing operation.

As best seen in FIG. 5, to retrieve the fluid-sampling apparatus 20, the control valve 35 (or 36) is actuated to open the normally closed hydraulic valve 51. By opening the valve 51, the high-pressure hydraulic fluid is admitted through the passage 50 into the enclosed annular spaces 85 and 97 (ahead of the pistons 79 and 53) that were initially at atmospheric pressure. Since the hydraulic pressure is greater than the hydrostatic pressure of the borehole fluids, as the hydraulic fluid enters these spaces and 97, the piston 79 and extendible member 53 are normally returned to their initial positions. Once these members 53 and 79 have been returned, the fluidsampling apparatus 20 can, of course, be either retrieved from the borehole 22 or repositioned therein. 1

It should be noted that the sampling tube 58 is not retracted when the outer tubular member 55 is restored to its original retracted position. Thus, for purposes of economy and safety, means must be provided for allowing the protruding portion of the sampling tube 58 to either bend readily or break off as the formation-sampling apparatus 20 is being moved through the borehole 22. This can, of course, be conveniently accomplished by either selectively weakening the forward portion of the sampling member 58 or else arranging the tube to bend easily under lateral loading.

In some instances, however, it will be recognized that the differential between the hydrostatic and formation pressures may be sufficient to hold the sealing member 87 firmly compressed against the formation 23. Accordingly, to prevent this, an equalizing valve 98 is arranged as seen in FIGS. 4 and 5 in such a manner that once the hydraulic valve 5 I is opened, the pressured hydraulic fluid will also open the equalizing valve to equalize pressures across the sample-admitting means 29 (or and 200) and facilitate disengagement of the sealing member 87 from the formation wall. When the valve 98 is in its normally-closed position (as seen in FIG. 4), the hydrostatic pressure of the borehole fluids will hold it closed so long as the hydraulic valve 51 is closed. As best seen in FIG. 5, therefore, opening of the hydraulic valve 51 will move the valve member 98 outwardly to admit the borehole fluids into the lateral housing bore 56.

Should there be some malfunction in the retracting system 31, as, for example, sticking of the hydraulic valve 51, the fluid-sampling apparatus 20 can still nevertheless be retrieved by the emergency release apparatus 52. Thus, should the necessity arise, the outer end of the extendible wall-engaging member 53 can be quite simply broken by picking up on the apparatus 20. Then, once the outer end ofthe axial passage 54 is opened, the borehole fluids will be admitted into the spaces 85 and 97.

Referring again to FIG. 3, it will be appreciated that during this portion of the operating cycle, there may be a momentary, but still substantial, pressure differential between the borehole fluids and the forward open end of the sampling tube 58. Thus, although the mudcake layer 96 (and/or the contiguous surface of the formation 23 as well) may generally be sufficiently competent to prevent channeling of the borehole fluids around the forward face of the packing element 87 and into the forward end of the sampling tube 58, there is nevertheless a distinct risk that such channeling could occur.

It will also be recognized that when the sample-admitting means 29 are in the position shown in FIG. 3, there will be a substantial pressure differential existing across the filtering screen 78 until the pressure in the housing bore 56 and flow line 43 rise to the formation pressure. Thus, even though the voided space 92 behind the piston member 60 will receive at least a portion of whatever materials are pulled off of the borehole wall, a significant quantity of the plug of mudcake 96 could also coat part ofthe screen 78.

Accordingly, to eliminate such undesirable coating of the screen 78 and channeling of borehole fluids through the mudcake 96 around the forward face of the elastomeric sealing members of the fluid-sampling apparatus 20, the present invention also includes an alternative embodiment I00 of sample-admitting means to be used with this apparatus. Since the balance of the sampling apparatus 20 is preferably arranged in the same manner with either the sample-admitting means 29 or the sample-admitting means 100, no change has been made in those reference numerals designating the unchanged elements of the formation-sampling apparatus of the present invention.

I Turning now to FIG. 6, the sample-admitting means 100 are shown in an initial position corresponding to the retracted position of the sample-admitting means 29 as depicted in FIG. 2. Similar to the sample-admitting means 29, the sample-admitting means 100 include inner and outer telescoped tubular members 101 and 102, with the outer member being slidably disposed in the lateral bore 56 of the tool body 44 and its forward end fluidly sealed within the O-ring 57. An annular elastomeric sealing member 103 is carried on a rigid support plate 104 that is mounted for limited swiveling movement on a spherically-shaped head 105 on the forward end of the outer tubular member 102. To selectively extend the sample-admitting means 100, an annular piston 106 is fluidly sealed, as by O- rings 107 and 108, within the coaxial annular bore 80 in the body 44, and the piston includes a tubular forward extension 109 that is sealingly extended through the O-ring 84 and connected to the spherical head 105.

The inner member 101 is generally arranged in a similar fashion to the sampling tube 58 and includes an enlarged piston head 110 on its rearward end that is sealingly engaged, as by an O-ring 111, within the forward portion of the axial bore 112 of the outer tubular member 102. An O-ring 113 is arranged within the spherical head 105 for sealing engagement around the forward portion of the sampling tube and defines an enclosed annular space 114 at atmospheric pres sure between the tubes 101' and 102 ahead of the piston member 110.

A tubular body 115 is coaxially mounted in the rearward portion of the axial bore 112 of the outer tubular member 102 and secured against longitudinal movement therein as at 116. Enlarged- diameter shoulders 117 and 118 on the forward and rearward ends of the tubular body are fluidly sealed by O-rings 11,9 and 120 within the outer tubular member to define an enclosed annular space 121 between the O-rings and the tubular members 102 and 115 that is initially at atmospheric pressure.

in its preferred form, the forward portion of the tubular body 115is counterbored, as at 122, and a restricted lateral passage 123 is arranged through the wall of the body for communicating the rear of the counterbore with the annular space 121.

An elongated valve member such as a cylindrical body 124 is slidably disposed in the tubular body 115 and provided with a pair of closely spaced O- rings 125 and 126 on its rear portion sealingly engaged within the reduced bore at the rear of the tubular body. An enlarged-diameter shoulder 127 near the forward end of the cylindrical body 124 carries an external ring 128 that is sealingly received within the counterbore 122 at the forward end of the tubular body 115. An axial bore 129 extending rearwardly from the forward end of the cylindrical body 124 is terminated at a lateral passage 130 through the wall of the body between the spaced O- rings 125 and 126 thereon. A tubular extension 131 from the forward end of the cylindrical body 124 and in coincidental alignment with the axial bore 129 is covered with a suitable filtering member or finely meshed screen 132 that covers a plurality of small apertures or lateral holes 133 in the tubular extension. The forward end of the tubular extension 131 is preferably closed by a transverse plug 134.

7 It will, of course, be recognized that with the sample-admitting means 100 in the illustrated retracted position, the cylindrical body 124 cannot move rearwardly; and the rearwardmost flanged end 135 of the body prevents the cylindrical body from moving forwardly in relation to the tubular body 115; As previously discussed in relation to the sample-admitting means 28, the enclosed counterbore 122 is initially filled with a viscous fluid which, as it is discharged through the passage 123 into the space 121, will regulate the speed of the rearward travel of the cylindrical body 124 as the sample-admitting means 100 are extended.

Accordingly, as far as has been described, it will be recognized that, in many respects, the sample-admitting means 100 are basically arranged in the same manner as the sample-admitting means 29. One significant distinction, however, is that, in its initial position shown in FIG. 6, the cylindrical body 124 and the O- rings 125 and 126 function as valve means blocking fluid communication (through the bore 129 and passage 130) between the rear of the lateral housing bore 56 and the tubular extension 131. Furthermore, another significant difference between the sample-admitting means 29 and is provided by a cylindrical plug 136 that is slidably disposed within a reduced bore 137 at the forward end of the sampling tube 101 and fluidly sealed therein, as by an O-ring 138, to function as valve means for preventing entrance of borehole fluids into' the sample-admitting means 100 so long as the sampling tube is retracted in relation to the outer tubular member 102. Although the plug 136 could just as well be mounted on the forward end of the tubular extension 131, it is preferred that the cylindrical plug be a separate member that is arranged to normally abut the transverse member 134 so as to not be shifted rearwardly by unbalanced pressure forces so long a the sampling tube 101 is retracted.

it will be appreciated, therefore, that with the sample-admitting means 100 retracted as shown in H6. 6, the interior bore 112 of the outer tubular member 102 (between the 0- rings 113 and is closed against entrance of borehole fluids. Similarly, the valve means respectively including the 0- rings and 138 selectively close the interior spaces of the sampling tube 101 and cylindrical body 124. Thus, in contrast to the sample-admitting means 29, when the sample-admitting means 100 are employed, borehole fluids cannot enter the formation-sampling apparatus 20 so long as the sample-admitting means 100 are retracted.

Accordingly, turning now to FIG. 7, the sample-admitting means 100 are depicted in a corresponding position as shown in FIG. 3 for the sample-admitting means 29. Since the operation of the tool 20 to this point will have been as previously explained, it is necessary only to point out that the hydrostatic pressure of the borehole fluids has been employed to extend the piston 106 so as to sealingly engage the packing element 103 against the mudcake layer 96 on the wall of the borehole 22. Once the piston 106 is stroked forwardly a sufficient distance to move the flanged end 135 of the valve member 124 away from the rear wall of the housing bore 38, the hydro static pressure of the borehole fluids will, of course, begin urging the forward plug or valve member 136, the tubular extension 131 and the cylindrical body 124 rearwardly in relation to the still retracted sampling tube 101. Rearward movement of these members is, however, selectively retarded by the fluent substance that is initially disposed in the counterbored annular space 122 around the cylindrical body 124. Thus, in the same manner as previously described for the sample-admitting means 29, the plastic substance initially disposed in the counterbore 122 must be slowly exhausted through the restricted passage 123 into the clearance space 121 as the cylindrical body 124 moves at a regulated speed to the rearward positions shown in FIGS. 7 and 8.

Rearward travel of the forward valve member 136 is operative to open the reduced entrance 137 of the sampling tube 101 before the O-ring 125 closing the lateral passage in the cylindrical body 124 clears the rearward end of the tubular body 115. Thus, with the sample-admitting means 100, only a minor momentarily-voided space, as at 139, is initially opened for receiving any plug of the mudcake 96 and loosened formation materials entering the sampling tube 101. As seen in FIG. 7, therefore, this mudcake plug will be disposed well behind the filtering screen 132 within the progressively enlarging space 139 respectively formed ahead of the shoulder 127 of the retreating valve body 124 and, if it moves, behind the advancing piston 110 of the sampling tube 101 as well. Then, after this initial quantity of mudcake enters the sample-ad mitting means 100, the passage 130 will open as the valve body 124 continues moving toward its rearwardmost position to establish communication with the additional voided spaces in the rear of the housing bore 56 and the open portion of the passage 43. The flow line valve 45 is, of course, still closed at this point.

Accordingly, although the sample-admitting means 100 function in a generally similar manner as the sample-admitting means 29, the significantly reduced volume of the initially voided space 139 (in relation to the combined volume of the space 92 and bore 56) will allow the sampling tube 101 to make at least a slight advancement into the formation 23 before the large volume of the housing bore is opened. It is believed, therefore,that if the nose of the sampling tube 101 can be first embedded into an unconsolidated formation before the passage 130 is opened, there will be a correspondingly reduced chance that the borehole fluids will channel through the mudcake 96 and contiguous formation wall supporting the forward face of the pad 103. It will also be appreciated that since only the voided space 139 is initially opened, all of the mudcake plug will be drawn into this space and, since there is no flow through the filtering screen, greatly minimize any coating over the screen 132.

In some instances, however, it has been found of added benefit to fill the passage 129 with a viscous fluid, such as grease or the like, before the apparatus is lowered into the borehole 22. When this is done, it will be appreciated that upon opening of the forward valve member 136, there is no tendency at all for the mudcake plug to be drawn onto the screen 132 since there is no pressure differential across the screen until the rearward valve means defined by the O-ring 125 and body 115 open. Similarly, if this technique is carried one step further, by also pre-filling the interior of the sampling tube 101 with a suitable liquid, opening of the forward valve meinber 136 will still further reduce the voided space 139 and require advancement of the sampling tube to develop at least a major portion of this space. Thus, since the sampling tube 101 will be advanced sooner, it will be even more responsive to moving into the formation 23 as loosened materials therefrom enter the sample admitting means 100. This more rapid response of the sampling tube 101 will, therefore, further assure the retention of an effective sealing engagement of the sealing member 103 with the borehole wall.

As seen in FIG. 8, once the flow line valve 45 is opened, the further operation of the sample-admitting means 100 will be the same as that of the sample-admitting means 29. Similarly, retraction of the sample-admitting means 100 will be as previously described in relation to FIG. 5.

Referring again to FIG. 6, it will be noted that the nose of the sampling tube 101 projects forwardly of the spherical head 105 and is about even with the forward face of the packing element 103 when the sample-admitting means 100 are retracted. Thus, when the piston 106 initially advances to compress the elastomeric pad 103 into sealing engagement against the mudcake 96, the face of the sealing member will move rearwardly in relation to the sampling tube 101 to leave the nose of the tube projecting slightly ahead. Accordingly, since the sampling tube 101 will still be seated against the tubular body 115 so long as the valve body 136 is in the bore 138, the forward thrust of the piston 106 will be operative to at least partially embed the nose of the sampling tube 101 into the mudcake 96.

As previously mentioned, however, it is preferred to make the sampling tube 101 relatively weak since it is not retracted once the sample-admitting means 100 are extended. Thus, to

reduce the axial load on the sampling tube 101 durir'ig the above described setting operation, a short rigid sleeve 140 is coaxially mounted in the forward end of the spherical head 105 and arranged to be about even with the nose of the sampling tube so long as the sampling tube is retracted. it will be appreciated, therefore, that although the engagement of the forward end of the sleeve 140 against the formation wall will reduce the axial loading on the sampling tube 101 during the setting operation, when the test is subsequently finished the extended sampling tube will still be readily bent or broken as the tool 20 is being moved from its sampling position.

Turning now to H6. 9, a third embodiment is shown of sample-admitting means 200 which may alternatively be employed in the apparatus 20 of the present invention.

Hereagain, the same reference numbers used in FIG. 2 have been retained to designate the previously-described common elements.

In general, it will be appreciated that the sample-admitting means 200 are somewhat similar to the sample-admitting means 100. Thus, in the same or similar fashion, the sampleadmitting means 200 include a tubular sampling member 201 that is slidably arranged for axial movement in the lateral housing bore 56 and has its forward portion fluidly sealed by the O-ring 57. An annular piston 202 is also sealingly arranged in the coaxial bore and includes a forward extension 203 projecting through the O-ring 84 and connected, as at 204, to the forward end of the tubular member 201. In the same manner as already described, a cylindrical valve member 205 is operatively arranged for selective movement in the axial bore 206 of the tubular member 201. Hereagain, spaced 0- rings 207 and 208 on the rear of the valve member 205 function as valve means for blocking communication through a central passage 209 therein so long as the O-rings are operatively engaged within a tubular body 210 secured within the rear portion of the sampling tube 201. Similarly, a tubular forward extension 211 of the cylindrical valve member 205 is perforated, as at 212, and supports a filtering screen 213 and a forward plug 214 adapted to be sealingly received within a reduced axial bore 215 that (in contrast to the sample-admitting means is formed in the nose of the tubular member 201. Inner and outer enclosed chambers 216 and 217 connected by a passage 218 are operatively arranged between the tubular body 210 and valve member 205 for regulating the rearward travel of the valve member as a viscous material is displaced from the inner chamber into the outer chamber.

An elastomeric packing element 219 is coaxially mounted on the forward end of the tubular member 201 and operatively arranged to be longitudinally compressed in relation to the tubular member as the sample-admitting means 200 are advanced into sealing engagement with a borehole wall. in the preferred manner of accomplishing this, the packing element 219 is symmetrically arranged in relation to the tubular member 201 and includes a transverse forward portion 220 having a central opening 221 carrying a tubular sealing member 222 coaxially disposed for movement over the tubular member 201 and a rearwardly directed peripheral skirt portion 223. By securing the skirt portion 223 of the packing element 219 to a rigid, transverse supporting plate 224 secured to an intermediate portion of the sampling tube 201 and leaving the forward transverse portion 220 free to move axially in relation to the tubular member, it will be appreciated that as the wall-engaging forward face of the elastomeric member engages a borehole wall the elastomeric element will compress and move rearwardly in relation to the sampling tube.

Accordingly, as best seen in FIG. 10, upon extension of the sample-admitting means 200, once the sealing element 219 engages the mudcake layer 96, the forwardly directed force developed by the piston 202 will be effective to sealingly engage the forward face of the transverse portion 220 on the borehole wall. Of particular significance, however, it will be recognized that a major portion of the force of the piston 202 will be effective for driving the nose of the sampling tube into the mudcake layer 96 and, quite possibly, the formation 23 as well. Thus, as the sealing member 219 moves rearwardly in relation to the tubular member 201, the sampling tube will, in effect, be advanced forwardly in relation to the outer tubular member 222 carrying the transverse portion 220 of the elastomeric member. it will also be appreciated that by providing one or more ports, as at 225, through the supporting plate 224, once the face of the elastomeric element 219 is sealingly engaged on a borehole wall the hydrostatic pressure of the borehole fluids acting on the rear face ofthe transverse portion 220 will be effective to enhance the sealing engagement.

Thus, as seen in FIG. 10, as the sample-admitting means 200 are being operatively engaged with a borehole wall, the valve plug 214 will initially be withdrawn from the forward reduced bore 215 in the sampling tube 201 to admit mudcake and any 'bore 56 and the formation 23. Hereagain, it will be understood that the flow line valve 45 is still closed. Thus, from this point on, it will be recognized that the operation of the tool 20 will be as previously described.

As one advantage of the sample-admitting means 200 over the sample-admitting means 29 and 100, the sampling tube 201 is adapted for positive retraction after a testing operation. Thus, the tubular member 201 can be made of sufficient strength to withstand the substantial axial loads necessary for positively driving it through the mudcake 96 and, possibly, into an unconsolidated formation.

Those skilled in the art will appreciate that irrespective of whether a water cushion, as at 41, is or is not employed, when a fluid sample is being taken there will be a substantial pressure differential existing between the connate fluids entering the forward portion of the sample-admitting means 29, 100 or 200 and the enclosed sample chamber 38 which is initially at atmospheric pressure. This extreme pressure differential must, of course, be accommodated in either instance. Thus, if the water cushion 41 and the other chamber 37 are employed, most of this pressure differential will be taken across the orifice 40 so that only a minimal pressure drop will occur in the sample-admitting means 29, 100 or 200. On the other hand, if the water cushion 41 is not employed in the tool 20, the pres sure drop will be primarily accommodated across the filtering screen 78 and the apertures 77 (and their corresponding elements in the sample-admitting means 100 and 200). If need be, additional flow restriction can be provided by arranging suitable orifices or the like (not shown) in either the passage 76 (or 129 and 209) or flow line 43.

in any event, there are, of course, widely different types of formations from which samples are to be taken. In those situations where the formations are fairly competent, it is not at all likely that the performance of the sample-admitting means 29, 100 or 200 would be affected by elimination of the water cushion 4]. On the other hand, the water cushion 41 may assure a more reliable operation with the sample-admitting means 29, 100 or 200 where a particularly uncemented granulated formation material is anticipated. The choice is, therefore, best determined by actual operating experience in each particular oil field.

,Turning now to FIG. 11, an alternative arrangement is shown for increasing the travel of the sample-admitting means 29, 100 or 200. Inasmuch as this arrangement is the same as shown in US. Pat. No. 3,385,364, it is necessary only to state that the two coaxially-arranged successively extendible pistons 300 and 301 can be readily employed as a substitute for the piston 79 of the sample-admitting means 29, the piston 106' of the sample-admitting means 100, or the piston 202 of the sample-admitting means 200. Since the unique cooperationof the pistons 300 and 301 is fully explained in the aforementioned patent, the details of their operation need not be described further.

Accordingly, it will be appreciated that the present invention has provided new and improved formation-sampling apparatus adapted for reliably establishing and maintaining fluid communication with various types of borehole surfaces and formation materials. Thus, although changes and modifications may be made in the principles of the invention as set out in the claims, by limiting the entrance of mudcake and any unconsolidated formation materials into the formation-sampling apparatus, greater assurance is had that satisfactory fluid samples will be obtained.

lclaim:

l. Fluid-sampling apparatus adapted for obtaining samples of connate fluids from earth formations traversed by a well bore and comprising: a support; sample-admitting means on said support and including inner and outer telescoped tubular members operatively arranged thereon for movement between retracted and extended positions; first means adapted for extending said outer member into engagement with an adjacent surface of a well bore; second means adapted for extending said inner member into engagement with a portion of such an adjacent well bore surface; and means operatively associated with said first and second means for delaying extension of said inner member until after extension of said outer member.

2. The fluid-sampling apparatus of claim 1 wherein said extension delaying means normally maintain said inner member retracted so long as said outer member is retracted.

3. The fluid-sampling apparatus of claim 1 further including: packing means operatively mounted on saidouter member and adapted to be carried thereby into sealing engagement around such'an adjacent well bore surface upon extension of said outer member.

4. The fluid-sampling apparatus of claim I further including: passage means operatively arranged within said inner member and adapted to conduct fluids entering said sampleadmitting means; filter means operatively arranged within said inner member and in fluid communication with said passage means for straining solid matter from such fluids entering said passage means; and means defining a space within said inner member and adapted for receiving such solid matter.

5. The fluid-sampling apparatus of claim 4 wherein said space is to the rear of said filter means for separating such solid matter from said filter means.

6. The fluid-sampling apparatus of claim 4 further including: valve means operatively associated with said extensiondelaying means for closing off said space until after extension of said outer member.

7. Fluid-sampling apparatus adapted for obtaining samples of connate fluids from earth formations traversed by a well fluent solid materials; sample-collecting means on said support including a first chamber adapted for receiving such connate fluids, and passage means arranged between said first chamber and said tubular member for conducting such connate fluids passing through said filtering means into said first chamber; means defining a second chamber in said tubular member adapted for receiving such fluent solid materials; and valve means normally closing said second chamber and adapted to be opened in response to extension of said tubular member for admitting such fluent solids into said second chamber.'

8. The fluid-sampling apparatus of claim 7 further including: means operatively associated with said tubular member and said valve means for delaying opening of said valve means until after extension of said tubular member.

9. The fluid-sampling apparatus of claim 7 further includ-. ing: selectively operable means on said support adapted for extending said tubular member; and means operatively associated with said tubular member and said valve means for delaying opening of said valve means until after extension of 1 said tubular member by operation of said selectively operable means.

10. The fluid-sampling apparatus of claim 7 further including: packing means operatively mounted on said tubular member and adapted to be carried thereby'into sealing engagement around such an adjacent well bore surface upon extension of said tubular member.

11. Fluid-sampling apparatus adapted for obtaining samples I of connate fluids from earth formations traversed by a well bore and comprising: a support; sample-admitting means on said support including a tubular sampling member having an.

internal bore and adapted for extension from said support to place the forward end of said sampling member into fluid communication with a well bore surface adjacent to earth formations; filtering means in said internal bore adapted for passing such connate fluids and retaining such fluent solid materials carried into said internal bore by such fluids; sample-collecting means on said support including a first chamber adapted for receiving such connate fluids, and passage means arranged between said first chamber and said internal bore for conducting such connate fluids passing through said filtering means into said first chamber; means defining a second chamber in said internal bore adapted for receiving such retained solid materials; valve means normally closing said forward end of said sampling member; and means operatively associated with said sampling member and said valve means for delaying opening of said valve means until said sampling member is being extended.

12. Fluid-sampling apparatus adapted for obtaining samples of connate fluids from earth formations traversed by a well bore and comprising: a support; sample-admitting means on said support including a tubular member adapted for extension from said support to place the forward end of said tubular member into fluid communication with a well bore surface adjacent to earth formations and including fluent solid materials, and a tubular sampling member having an internal bore and telescopically arranged within said tubular member for extension through said forward end thereof; filtering means in said internal bore adapted for passing such connate fluids and retaining such fluent solid materials; sample-collecting means on said support including a first chamber adapted for receiving such connate fluids, and passage means arranged between said first chamber and said internal bore for conducting such connate fluids passing through said filtering means into said first chamber; means defining a second chamber in said internal bore to the rear of said filtering means and adapted for receiving such fluent solid materials; and valve means normally closing said second chamber and opened in response to extension of said tubular member for admitting such fluids and fluent solids into said second chamber.

13. The fluid-sampling apparatus of claim 12 further including: means operatively associated with said tubular member and said valve means for delaying opening of said valve means until after extension of said tubular member.

14. The fluid-sampling apparatus ofclaim 12 further including: means responsive to admission of such fluids and fluent solids into said second chamber for extending said sampling member through such forward end of said tubular member; and means operatively associated with said tubular member and said valve means for retarding opening of said valve means until after extension of said tubular member to delay extension of said sampling member.

15. Fluid-sampling apparatus adapted for obtaining samples of connate fluids from earth formations traversed by a well bore and comprising: a support; sample-admitting means on said support including a tubular member adapted for extension from said support to place the forward end of said tubular member into fluid communication with a well bore surface adjacent to earth formations and including fluent solid materials, and a tubular sampling member having an internal bore and telescopically arranged within said tubular member for extension through said forward end thereof; filtering meansjn said internal bore adapted for passing such connate fluids and restraining such fluent solid materials; sample-collectingmeans on said support including a first chamber adapted for receiving such connate fluids, and passage means arranged between said first chamber and said internal bore for conducti'ng such connate fluids passing through said filtering means into said first chamber; means defining a second chamber in said internal bore to the rear of said filtering means and adapted for receiving such fluent solid materials; and valve means normally closing the forward end of said sampling member to close said second chamber and operatively arranged to be opened in response to extension of said tubular member for admitting such fluids and fluent solids into said second chamber.

16. The fluid-sampling apparatus of claim 15 further including: means operatively associated with said tubular member and said valve means for delaying opening of said valve means until after extension of said tubular member.

17. The fluid-sampling apparatus of claim 15 further including: means responsive to admission of such fluids and fluent solids into said second chamber for extending said sampling member through such forward end of said tubular member; and means operatively associated with said tubular member and said valve means for retarding opening of said valve means until after extension of said tubular member to delay extension of said sampling member.

18. Fluid-sampling apparatus adapted for obtaining samples of connate fluids from earth formations traversed by a well bore and comprising: a support; sample-admitting means on said support including a tubular member having an internal bore and adapted for extension from said support to place the forward end of said tubular member into fluid communication with a well bore surface adjacent to earth formations and including fluent solid materials; filtering means in said internal bore adapted for passing such connate fluids and retaining such fluent solid materials; sample-collecting means on said support including a first chamber adapted for receiving such connate fluids, and passage means arranged between said first chamber and said internal bore for conducting such connate fluids passing through said filtering means into said first chamber; means defining a second chamber in said internal bore adapted for receiving such fluent solid materials; and valve means normally closing said forward end of said tubular member to enclose said second chamber and operatively arranged to be opened in response to extension of said tubular member for admitting such fluids and fluent solids into said second chamber.

19. The fluid-sampling apparatus of claim 18 further including: means operatively associated with said tubular member and said valve means for delaying opening of said valve means until after extension of said tubular member.

20. The fluid-sampling apparatus of claim 18 further including: second valve means normally closing said passage means and operatively arranged to be opened in response to extension of said tubular member for admitting such fluids into said first chamber; and means operatively associated with said tubular member and said first and said second valve means for retarding opening thereof until after extension of said tubular member.

21. The fluid-sampling apparatus of claim 20 wherein said first valve means are adapted to be opened before said second valve means are opened.

22. Fluid-sampling apparatus adapted for obtaining samples of connate fluids from earth formations traversed by a well bore and comprising: a support having an open bore therein; a tubular member operatively arranged for axial movement in said bore between a retracted position and an extended position and having a forward end adapted for engagement with a wall of a well bore upon movement to said extended position; packing means operatively mounted on said forward end of said tubular member and adapted to be carried thereby into sealing engagement with such a well bore wall for isolating said forward end of said tubular member from well bore fluids; a movable body having a passage extending between forward and rearward portions thereof coaxially mounted within said tubular member for axial movement therein between first and second positions; means selectively operable for moving said tubular member from its said retracted position to its said extended position; filtering means on said forward portion of said body in communication with said passage and adapted for straining fluent solid materials from such connate fluids admitted into the annular space between said body and said tubular member and passing into said passage; valve means operatively arranged between said forward portion of said body and said tubular member for closing fluid communication between said.forward end of said tubular member and said annular space so long as said body is in one of its said positions; and means normally positioning said body in its said one position and responsive to movement of said tubular member toward its said extended position for shifting said body to the other of its said positions to open said valve means.

23. The fluid-sampling apparatus of claim 22 further including: means operatively associated with said body for delaying shifting of said body to its said other position.

24. The fluid-sampling apparatus of claim 22 further including: sample-collecting means on said support including a chamber adapted for receiving such connate fluids, and passage means operatively coupled between said chamber and said passage.

25 The fluid-sampling apparatus of claim 22 further including: second valve means operatively arranged between said rearward portion of said body and said tubular member for closing fluid communication through said passage so long as said body is in its said one position.

26. The fluid-sampling apparatus of claim 25 further including: means operatively associated with said body for delaying shifting of said body to its said other position.

27. The fluid-sampling apparatus of claim 26 wherein said second valve means are adapted to remain closed until after said first-mentioned valve means are opened.

28. Fluid-sampling apparatus adapted for obtaining samples of connate fluids from earth formations traversed by a well bore and comprising: a support having an open bore therein; sample-admitting means on said support including a tubular member operatively arranged for axial movement in said bore between a retracted position and an extended position and having a forward end adapted for engagement with a wall of a well bore upon movement to said extended position, and a tubular sampling member having an internal bore and telescopically arranged within said tubular member for extension through said forward end thereof; packing means operatively mounted on said forward end of said tubular member and adapted to be carried thereby into sealing engagement with such a well bore wall for isolating said forward end of said tubular member from well bore fluids; a movable body having a passage extending between forward and rearward portions thereof coaxially mounted within said tubular members for axial movement therein between first and second positions; means selectively operable for moving said tubular member from its said retracted position to its said extended position; filtering means on said forward portion of said body in communication with said passage and adapted for straining fluent solid materials from such connate fluids admitted into the annular space between said body and said sampling member and passing into said passage; valve means operatively arranged between said forward portion of said body and said sampling member for closing fluid communication between the forward end of said sampling member and said annular space therebehind so long as said body is in one of its said positions; and means normally positioning said body in its said one position and responsive to movement of said tubular member toward its said extended position for shifting said body to the other of its said positions to open said valve means.

29. The fluid-sampling apparatus of claim 28 further including: means operatively associated with said body for delaying shifting of said body to its said other position.

30. The fluid-sampling apparatus of claim 28 further including: sample-collecting means on said support including a chamber adapted for receiving such connate fluids, and passage means operatively coupled between said chamber and said passage.

31. The fluid-sampling apparatus of claim 28 further including: second valve means operatively arranged between said rearward portion of said body and said tubular member for closing fluid communication through said passage so long as said body is in its said one position.

32. The fluid-sampling apparatus of claim 31 further including: means operatively associated with said body for delaying shifting of said body to its said other position.

33. The fluid-stamping apparatus of claim 32 wherein said second valve means are adapted to remain closed until after said first mentioned valve means are opened.

Images