US2218155A

US2218155A - Formation tester

Info

Publication number: US2218155A
Application number: US314324A
Authority: US
Inventors: George W Rusler; Victor V Vacquier
Original assignee: Gulf Research and Development Co
Current assignee: Gulf Research and Development Co
Priority date: 1940-01-17
Filing date: 1940-01-17
Publication date: 1940-10-15
Anticipated expiration: 1957-10-15

Description

Ogt. 15, 1940- G. w. RUSLER ET AL FORMATION TESTER Filed Jan. 17, 1940 2 Sheets-Sheet 2 v gwwem co'ps 95 VICTOR V. VACQUIER WE'LL FLU ID S GEORGE w. 1 0 sLER Patented Oct. 15, 1940 UNITED STATES PATENT. OFFICE FORMATION TESTER .George W. Rusler, Penn Township,

Allegheny County, and Victor V. Vacquier, Oakmont, Pa., assignors to Gulf Research & Development Company, Pittsburgh, Pa., a corporation of Delaware Application January 17, 1940, Serial No. 314,324

10 Claims.

This invention or discovery relates to formation testers; and it comprises, in apparatus for testing fluid production in wells, the combination of a string of tubing adapted for communication with the well at some level thereof and to receive fluids from the well, at least one hydraulically expansible packer surrounding the tubing and adapted to engage the well or casing walls, means for applying pressure from said tubing to the packer to expand it against the walls, means for limiting said applied pressure to a safe value and means operable from the top of the well for releasing pressure on the packer'at will; all as more fully hereinafter set forth and as claimed.

In drilling oil and gas wells and in operating completed wells it is sometimes desirable to test certain rock formations to determine what fluids (gas, oil or water) they are producing and to determine the rate of production. The usual pro cedure is to lower into the well a string of tubing having a packer at its lower end, that is a device which can be mechanically expanded against the well wall to seal the upper part of the well from the lower. Sometimes a string of drill pipe is used in lieu of tubing; hereinafter tubing refers to both tubing proper and to drill pipe. When the packer is expanded hydraulic connection between the inlet of the tubing pipe and the rock strata above the packer are cut off. Whatever fluid may be produced through the tubing is known to come from levels below that at which the packer is set. A swab or bailer is run in and operated to withdraw any fluid entering the tubing, for study and measurement.

In ordinary formation testing apparatus, the bottom of the packer is connected to a length of pipe called the anchor. When the assemblage of tubing, packer and anchor is lowered until the anchor reaches the bottom of the well, the packer is expanded by the full weight of the tubing string applied thereto.

One disadvantage of such formation testers is that once the packer is set it is impossible to reset it at a difierent depth without pulling the entire string of tubing and fitting a new anchor of different length. In many cases a new packer rubber has to be used for each setting because packer from very deep wells, the tubing is subjected to a considerable overload; a load sometimes sufiicient to part the tubing.

Proposals have been made to provide formation testers with hydraulically expansible packers ar- 5 ranged to avoid some of the disadvantages of the conventional apparatus, but in general these devices have sufiered from undue complication and from the necessity of providing an additional string of tubing; an operation to be avoided if possible.

Among the objects of the present invention is the provision of a formation tester adapted to be set and removed at one or more levels in a well without the necessity of withdrawing the apparatus from the well. Another object is the provision of a formation tester incuding a packer so arranged that the packer is expanded under fluid pressure applied through the tubing string, and means are provided for limiting the applied pressure to a safe value, so that the packer does not adhere to the well walls. Another object is the provision of a formation tester with a hydraulically expansible packer arranged in conjunction with an air cushion device so that the packer can accommodate itself to giving away of the formation rock. Another object is the provision of a formation tester adapted for testing wells under pump operation and arranged for setting at any desired level ina well. 30

In the accompanying drawings are shown more or less diagrammatically three examples of specific embodiments of apparatus within the purview of the invention. In the drawings:

Fig. l is a view in elevation of one form of the apparatus installed in a well,

Fig. 2 is an enlarged sectional view, with some parts in elevation, of a modification of the apparatus of Fig. 1, fitted with a single packer,

Fig. 3 and Fig. 4 are enlarged fragmentary 40 sectional views, with some parts shown in elevation, of a modified form of apparatus,

Fig. 5 is a view in elevation of the complete apparatus of Figs. 3 and 4, and

Fig. 6 is a fragmentary sectional view taken along line 6-6 of Fig. 2. v Referring to the drawings and in particular to Figs. 1 and 2, the apparatus is shown (Fig. 1 as installed in a well ill shown as uncased though it may be cased, assumed to have a fluid-producing formation II. A string of tubing l2 extends downward from the surface, and carries at its lower end a fluid-tight cylinder or housing l3 and two packers l4 and N4 of similar construction. Each packer includes an expansible halg the slot (Fig. 6).

icon or sleeve I5 of heavy rubber hose having upper and lower canvas-reinforced rings I6 and of the test pipe being capped at 21. Pipes 25 and I25 are joined by a length of pipe 34, having an orifice 28 between the two packers to receive well fluids. The upper packer is retained to the bottom closure 29 by a screw collar 30 on pipe 25.

Cylinder I3 encloses the operating and control mechanism for setting and releasing the packers. A plate I45 forming the upper closure of cylinder I3, carries an inner cylinder I46 ported at I41 and in threaded engagement at the lower end with valve body member I48. A middle sleeve I49 joined to the lower end of tubing I2 through a coupling I50 fits snugly but rotatably within cylinder I46 and is retained against upward movement by a shoulder I5I engaging a recess I52 in the cylinder I46. Downward longitudinal movement of the middle cylinder is restrained by the body member I48. Rotation of middle sleeve I49 with respect to element I46 is restrained to a definite angular range by the provision of an arcuate slot I53 on the periphery of the shoulder I5I of sleeve I49 and stop screw I64 carried by cylinder I46 and projecting into A port I55 is provided in mid- .dle cylinder I49 and is so located with respect to slot I53 as to register with port I41 when pin I54 is atone end of the slot and to be completely out of register with port I 41 when the middle cylinder is rotated to bring pin I54 into contact with the'other end of the slot. An inner sleeve member I56 forms a close sliding fit within the middle sleeve I 49 and is restrained from rotation with respect thereto by key-way I51 and key I58. A port I60 is provided in the inner sleeve to register with ports I41 and I55 when the inner sleeve is in its uppermost position in contact with coupling I50, as shown in Fig. 2. Inner sleeve I56 is normally maintained in its uppermost position by the action of a spring I6I between body member I48 and base I62 of the inner sleeve. A short tube I63 advantageously integral with base I62, projects upwardly inside the inner sleeve to a level above port I 60 and its bore, providing fluid communication from a point above the level of port I60 to the opposite side of base I62. The valve body I48 carries a plunger I64 loaded with a spring I99 projecting upwardly out of the valve body and adapted, when struck by tube I63, to depress a lever I65 which is pivoted on a support I 66 and operatively connected to a smaller spring-loaded plunger I61. Plunger head I68 fits in valve cage I69 and in its uppermost position is adapted to hold a ball I against the opening of a duct I 1|. Depression of plunger I61 releases the ball and places duct "I in communication with a duct I12 leading to the exterior of the casing through a tube I13. Duct I1I is in communicationwith the interior of the packer through a ball valve recess I14, passageway I15, pipes I16 and I11 and a passageway I18. Ducts HI and I communicate with the interior of tub ng I2 through a bore I19 normally closed by a spring-pressed ball valve I92.

A pneumatic vessel "I is joined to valve body 36 and includesa cylinder head I82 and bottom closure I83 with a free sliding piston I84 interposed therebetween. Air may be injected into the chamber between the cylinder head and piston through check valve I85 and conduit I86 normally closed by plug I81 in plate I45 of cylinder I3. The chamber between closure I83 and the piston is in communication with pipe I11, as shown, througha frustoconical seat I88 accommodating an extension I89 of similar shape on the lower extremity of the piston I84. Communication between pipe 25 and the tubing I2 is aflorded through a plurality of openings I90 in plate 29.

In operation, before the packer is introduced into the well the coupling I50 is turned as with a wrench to place port I55 out of register with port I41, thus preventing any fluid in the well from flowing through the mechanism during descent; Plug I81 is removed and air or other gas introduced into vessel I8I through valve I 85 under a pressure somewhat less than the formation pressure to be expected at the level to be tested. Such pressure may vary from a few pounds to several thousand pounds per square inch. Suflicient oil (not shown) is introduced to fill the packers without expanding them and to fill pipe I16. Under these conditions piston I84 rests on closure I83, under air pressure. The apparatus is then lowered to the desired level. On reaching the position at which the packer is to be set, the tubing I 2 is filled with oil and pressure is applied by pump 6I, which is transmitted through tube I63 and passageway I19 and forces valve ball I92 away from its seat, thus placing the inside of the packer under the pressure of the oil in the tubing through pipes I16 and I11 and passageway I 18, and at the same time placing the lower side of piston I84 under the pressure of the oil in the tubing through pipe I11.

As the pressure increases oil flows through pipe I 16 to th interior of the packers and to the lower part of vessel I8I. The packers are expanded against the well walls, making a tight seal. The pressure, read at gage 62, is kept low enough to avoid adhesion of the packer rubbers to the rock. If the well contains liquid above the packer assemblage the height of the liquid column is allowed for in determining the differential pressure to be maintained on the packers. This application of pressure simultaneously forces piston I84 upwardly in the air cylinder against the pressure of the compressible gas therein. Should the formation give way a little, as sometimes happens after the packer is set, some of the reserve oil below the piston will fiow into the packers and expand them, thus preserving the seal. The pneumatic vessel I8I and piston I84 thus make up an accumulator.

With the packer set, tubing I2 is rotated so as to place port I55 in register with ports I41 and I 60 whereupon a swab or bailer (not shown) is run in the tubing in a known way to test production. Assuming the apparatus to be opposite a producing formation (Fig. 1) well fluids will flow in through port 28, pipe 25, ports I90, I41, I55 and I80. In some cases the formation pressure is sufficient to cause formation liquids to rise to the top of the well, in which case no conpositiOIi in the Well, tubing I2 is first rotated 15 III so as to place ports I41 and I55 out of register, and then a. messenger I94 is lowered on a wire line I95 until it strikes tube I63 depressing sleeve I56 against the action of spring I6I until plunger I64 is depressed against its spring causing lever I65 to depress plunger head I68. Valve ball I10 then falls from its seat placing vent pipe I13 in communication with the inside of the packers through ducts I12 and I15 and pipe I16. The pressure in the packers is thus relieved and the packers deflated. The messenger is then withdrawn whereupon the sleeve I56 and the plunger I 64 return to their original uppermost positions, and ball I10 is forced against its seat. The mechanism is then lowered to the new position whereupon the operations previously described for inflating the packers are repeated. If desired, the strengths of the springs associated with valve I10 and plunger I64 may be so adjusted as to limit the pressure attainable in the packer, whereupon valve I10 acts as a relief valve. Of course, the springs should be made strong enough to keep the valve closed within therange of pressures that will be encountered in a given well.

When it is desired, after having once set the packer, to remove it to a higher position, or to remove the apparatus from the well, different technique is employed to avoid a wet job in pulling the tubing string. Tubing I2 is not rotated as before, but ports I41 and I55 are left in register. The messenger is lowered to release exhaust valve I10, thereby deflating the packers. In so doing, tubing I2 is temporarily placed out of communication with pipe 25 because port I60 is out of register with ports I41 and I55, and hence the tubing fluid cannot be emptied until the deflation of the packers is completed. After deflation of the packers, the messenger is removed, whereupon the sleeve I56 again rises to its original position placing ports I41, I 55 and I60 in register and allowing the tubing to drain into the well through passages I90 and pipe 25. When the higher position is reached at which it is desired to set the packer, the messenger is again lowered suificiently to depress sleeve I56 by an amount suflicient to place port I60 out of register with ports I41 and I55, but not suflicient to cause depression of plunger I64. With communication between the tubing and the formation thus closed on, oil pressure may again be applied to the packer interiors and the vessel I 8I. After the packers are set the messenger is again removed and the formation-produced as before, port I 60 again being in register with ports I41 and I55. The portion of the apparatus between the upper side of valve body I46 and closure I45 need not be constructed to the vertical scale shown in the drawings but if desired can be made relatively longer, to afford greater latitude in positioning the sleeve I56 so that port I60 is out of register with ports I41 and I55 while the lower end of tube I63 does not come in con tact with plunger I64. The range of travel of sleeve I56 may be several feet if necessary.

If it is desired merely to test for production below a certain single level, as in bottom-hole testing, instead of testing for production between two levels, the lower packer I I4 and its fluid connection 59 are simply omitted, and coupling 64 for tube 59 is replaced by a plug (not shown).

It is often desirable to test fluid producing formations under conditions of steady pumping. n the average, pumping wells produce about 4 barrels of water for each barrel of oil. 7 In many wells it is possible to take steps to reduce the water-oil ratio if the depth at which water enters the well can be accurately determined.

Figs. 3, 4 and 5 show a modification of the invention adapted for testing formations under pumping conditions. Fig. 4 is a continuation of Fig. 3; point X on Fig. 4 corresponds to point X on Fig. 3.

The apparatus includes a pump, of conventional construction per se, including a working barrel II2, adetachable standing valve in the lower portion of the barrel, and a conventional valved piston 1I adapted to be reciprocated from the surface by a rod 12. A catch 68 extending below the piston is provided, adapted to engage a post 69 on the standing valve for pulling the standing valve when desired. Two packers 2I4 and 3I4 are provided of construction quite similar to packers I4 and H4 of Fig. 1. Working barrel H2 is adapted to be attached directly to the string of tubing I2 and is of smaller diameter than the tubing as shown in Fig. 5. In a pumping well, the lower extremity of the tubing reciprocates through a range of a foot or two due to the loading and unloading of the tubing as the pump piston intermittently picks up the load of the fluid column on the upstrokes. Since the packers when once set remain stationary in the well, it is necessary to make some provision for a relative movement between the packer assembly and the working barrel or tubing. In the specific embodiment illustrated in Fig. 3, this is accomplished as follows: There is provided an annular member 14 surrounding the pump barrel H2 and carrying packing 15 to make a snug sliding fit with the barrel. Member 14 carries a protective casing 13 enclosing the working parts of the packer controlling mechanism, which casing is closed at the bottom by closure member 16. Guide sleeve 11 is disposed concentrically with respect to the barrel H2 and is carried in threaded engagement with element 14 as at 18. A threaded closure ring 80 engages a pipe nipple 8|, which in turn engages the central bore 82 in closure 16, thus affording communication through the ring 80 and closure 16 between the inlet 86 of the standing valve 10 and the pipe 88 carrying well fluids through the packers. A member 83 is attached to the lower end of barrel H2 and forms a seat for standing valve 10. Member 83 carries packing 85 and packing ring I30 which together with the member 83 form a fluid-tight, sliding fit with sleeve 11. Thus, the working barrel H2 and pump piston H are each free to reciprocate with respect to element 14 and its associated parts. In order to permit hanging the packer assembly on the tubing when lowering into the well without interfering with communication between the interior of the tubing and port I08, element 83 is provided with a lip A at its upper extremity thus affording an annular space between the element 83 and the outer wall of barrel H2. A lip B is likewise provided on the lower extremity of member 14 and is so arranged as to contact lip A of the working barrel when the packer assembly is hung on the barrel. Lip B projects downwardly between sleeve 11 and barrel H2 with clearance on both sides, and a port I3I provides communication between the annulus on each side of the lip B.

Each packer comprises a rubber hose I5 attached to a spool 20. A pipe 88 threadedly attached to member 16 extends through the upper packer as shown (Fig. 4). The upper packer is retained against member I6 by a threaded ring 89 engaging the annular closure 90 of the packer. Packing 200 is arranged between closure 90 and a ring 20I welded to pipe 88, as shown. Pipe 88 is coupled by a coupling 9| with a lower pipe 92 extending through and ca y ng the lower packer. Supporting ring 202 is welded to pipe 92 and lower packer 3I4 is held thereagainst by a head 490 and a threaded ring 95 engaging threads on pipe 92. The joint between head 490 and pipe 92 is sealed by packing 98 held by gland 93 and ring I98 which is welded to pipe 92 at 94. Between gland 93 and ring I98 a suitable number of washes I99 is disposed to adjust the tightness of the packing in conformity with the overall length of the packer. A-similar gland and adjusting washes are provided between ring 20I and closure 90 of the upper packer 2. The two packers are joined by a tube 59 as in Figs. 1 and 2.

The lower pipe 92 carries an inner pipe 98 in telescopic sliding relation therewith and having a flanged cap 99 at the bottom. Pipe 98 has a stop I00 sliding in a slot IOI in pipe 92, to restrain motion of pipe 98 to a fixed range. Pipe 98 has a port I02 adapted to register with a port I03 in pipe 92 in the upper position of pipe 98. A coil spring I04 urges pipe 98 downward, with a force sufiicient to prevent upward movement of the pipe under any formation pressures encountered. The length and limits of movement of pipe 98 are such that when extended downwardly to its lowermost position port I05 in pipe 92 is open and port I03 in pipe 92 is closed. When pipe 98 is moved upwardly to its uppermost position port I05 is closed and port I03 opened through registry with port I02 in pipe 98.

In the apparatus of Figs. 3, 4 and 5, the packers are expanded under pump pressure, which pressure is kept to a safe value. As shown, the pump working barrel is ported at I08 and at I01 and the guide cylinder TI is ported at I08. Port I08 communicates through an elbow fitting I09 and a tube H0 and a duct H3 in valve cage III; a plunger valve I 42 being interposed in the duct. Duct II3 communicates through chamber I44 and duct II5 with the interior of the u per packer 2I4. Thus, as pressure is built up lri tubing II2 above the standing valve I0, liquid is forced into the packers, expanding them against the well walls.

Valve I42 has a plunger II8 which is surrounded by a flexible metallic bellows H9 and urged downwardly by a spring I20, arranged. as shown. The interior of the bellows is vented to the interior of the well by a duct 205 and a port 204 in the casing 13. Upon development of excessive pressure in the packers and in chamber I44, the pressure in chamber I44 acting on the bellows closes the ball valve so that no more pressure fluid reaches the packers.

The lower closure 80 of the guide sleeve is fitted with a ball valve I2I in a cage I22 which is connected through a tube I24 and a duct 225 in member I6 with the interior of the packers. The valve ball is normally urged upward by a spring I26 as well as by fluid pressure inthe packers. A pin I2'I urged upward by a spring I28 is so arranged that by lowering the pump assembly to its lowermost position, the pin is depressed to open the ball valve and thereby release pressure on the packers through a duct I23 which connects valve cage I22 with the interior or casing I3 and hence with the well fluid through port 204.

The operation of the apparatus of Figs. 3, 4 and 5 is as follows: As the apparatus is being lowered into the well, the packer assemblage hangs in its lowermost position with respect to the pump, that is with the lip A of the pump-closure 83 resting against the lip B of closure 14. The packers are in collapsed condition. When the apparatus reaches the desired level, the pump is put into operation. As the pump operates the liquid column rises in the tubing string thus causing an increase in pressure in the pump barrel (space 206) which is communicated to the packers through ports I08 and I08, tube IIO, duct II3, chamber I44 and duct II5. When the packers grip the walls of the well sumciently to support the weight of the packer assembly, then the pump barrel I I2 will reciprocate downwardly from its initial position (with parts A and B in contact) as the load on the tubing due to the rising fluid column is increased. Soon the relative pressure between the pump chamber and the fluid column in the well above the packers reaches the predetermined shutoff valve for which valve I42 is set, whereupon the valve closes as described and the packer is locked in its expanded condition. Should any leakage take place in the packer system, reducing pressure therein, valve I42 automatically opens. During the test the assemblage of the two packers and the attached casing I3 remains stationary, while the pump barrel I I 2 reciprocates with respect to the packer assembly and the pump piston reciprocates with respect to the barrel II 2 and the packer assemblage.

Thus the packer is automatically set simply by starting up and operating the pump, and the reciprocation of the tubing string is accommodated without straining the packing assembly.

In order to release the packer, the standing valve 10 is pulled out or working barrel II2 into the larger diameter tubing I2 whereupon the fluid column in tubing I2 escapes around plunger II and valve 10 into the well, then the tubing string is simply lowered until member I30 depresses pin I21 and opens exhaust valve I2I.

This establishes hydraulic connection between the packer interior and the well fluid through ports I23 and 204, whence'there is considerable relief of the pressure inside the packer, in consequence of which the packer will no longer sustain the weight of the packer assembly which moves downward in the well, permitting relief valve I2I to close; As the packers are not en-.

tirely deflated when valve I2I closes, there is still some mechanical drag, and this is overcome as follows: The partial relief of pressure inside the packers afforded by opening the relief valve I2I is sufllcient to cause valve I42 to open under the influence of spring I20, and hydraulic connection between the packers and the well is thus established through ports I06 and I0! and opening 86. The pressure within the packers is thus entirely relieved and the disengagement of the packer from the walls of the well is complete.

The sliding tube 98 is arranged to permit tests of bottom hole pressure in addition to tests of production between fixed limits. Thus by lower- .ing the whole apparatus to the bottom of the well causes ports I02 and I03 to be shut oil and port I05 to be open as shown in Fig. 4.

The apparatus of Figs. 3 to 5 can, of course, be employed as a single packer formation tester by simply omitting coupling 9| and all parts below it The apparatus is embodied in the usual materials for oil well apparatus such as steel and bronze.

What we claim is:

1. A formation tester for wells comprising in combination a string of tubing extending down the well, a hollow hydraulically expansible packer adjacent the lower end of the tubing, a sampling pipe in communication with the tubing, extending through the packer to a portion of the well below the packer, valve means for said pipe closable to prevent flow of liquid therethrough while the packer is being lowered, operable from the top of the well, a duct leading from the tubing to the interior of the packer, check valve means in said duct opening toward the packer, whereby upon development of pressure in the tubing the packer is expanded and pressure in the packer is held by the check valve, and packer vent means operable from the top of the well for venting the interior of the packer to the well.

2. A formation tester for wells comprising in combination a string of tubing extending down the well, a hollow hydraulically expansible packer adjacent the lower end of the tubing, a sampling pipe in communication with the tubing and extending through the packer to the well space below the packer, valve means for said pipe closable to prevent flow of liquid therethrough while the packer is being lowered, operable from the top of the well, a duct leading from the tubing to the interior of the packer, check valve means in said duct opening toward the packer, whereby upon development of pressure in the tubing the packer is expanded and pressure therein is held by the check valve, pressure-limiting means in communication with the packer and adapted to limit pressure in the packer to a predetermined moderate value, and packer vent means operable from the top of the well for venting the interior of the packer to the well.

3. In a formation tester for Wells including a string of tubing extending down the well, a hollow hydraulically expansible packer adjacent the lower end of the tubing, a sampling pipe in com: munication with the tubing and extending through the packer to the well space below the packer, a duct leading from the tubing to the interior of the packer for application of fluid pressure to the interior of the packer, and a check valve in said duct for holding pressure in the packer, the improvement comprising a pressure accumulator in liquid communication with the interior of the packer, adapted to retain a reserve of pressure fluid in communication with the packer, so that the packer is kept in expanded condition upon caving of the well walls.

4. In combination, a string of tubing extending downwardly into a well, a formation tester attached to the bottom of said tubing comprising a pair of vertically spaced hydraulically expansible packers, a fluid conduit through the interior of the upper packer connecting the tubing with a well space intermediate the two packers, movable means in said conduit adapted in one position to prevent flow of fluid from the tubing to the well and in another position to permit flow thereto, mechanical means operable from the surface of the well independently of said tubing, said mechanical means being adapted to move said movable means from one to the other position when the packers are unset and hanging on the tubing, 8, fluid passageway connecting the hydraulically expansible portion of both packers with the interior of the tubing, a one-way valve in said passageway adapted to admit to the expansible portion of the packers and retain therein fluid under pressure from the tubing and mechanical means operable from the surface for venting the expansible portion of both packers to a space exterior of the tubing and the packers.

5. In combination, a string of tubing extending downwardly from the surface of a well, a formation tester attached to the bottom of said tubing comprising a pair of vertically spaced hydraulically expansible packers, a fluid conduitconnecting with the tubing and extending through the interior of both packers, movable means in said conduit adapted in one position to prevent flow of fluid from the tubing to the well and in another position to permit flow thereto, mechanical means operable from the surface of the well independently of said tubing, said mechanical means being adapted to move said movable means from one position to the other when the packers are unset and the tester is hanging on the tubing, a fluid passageway connecting the hydraulically expansible portion of both packers with the interior of the tubing, a one-way valve in said passageway adapted to admit to the expansible portion of the packers and retain therein fluid under pressure from the tubing, mechanical means operable from the surface for venting the expansible portion of both packers to a space exterior of the tubing and the packers, an opening in said conduit communicating with the well space intermediate said two packers, a second opening in said conduit communicating with the well space below the lower packer and a spring-urged member extending downwardly below the lower packer and movable vertically with respect thereto, said member being adapted to open said first-named opening and close said second-named opening when extended downwardly under the urge of the spring and to open said second-named opening and close said first-named opening when moved upwardly through contact with the bottom of the well on lowering the tester.

6. Apparatus for testing fluid production in wells comprising a string of tubing adapted for communication with the well at some level thereof and to receive fluids therefrom, at least one hydraulically expansible packer surrounding the tubing and adapted to engage the well walls, a housing in fixed relation to the packer, a pump barrel attached to the lower portion of the tubing and in reciprocable relation to the housing, a. pump plunger in reciprocal relation to the pump barrel, a standing valve in said pump barrel, said plunger and said standing valve defining a chamber in said barrel, conduit means connecting the pump chamber with the packer so that upon operation of the pump the packer is expanded against the well walls, relief valve means in said conduit means adapted to bypass fluid from the packer when the fluid pressure rises above a predetermined value, and valve means in the housing operable by the pump barrel in one position thereof, for releasing pressure in the packer to collapse the packer.

7. Apparatus for testing fluid production in wells comprising a string of tubing extending down the well, a housing attached to the tubing, 2. pump mounted in the housing in reciprocating adapted to engage the well walls, conduit means extending from below the packer to the pump for passage of well fluids to the pump, conduit means connecting the pump chamber with the packer for expansion of the packer by pump pressure, valve means in said conduit means adapted to close said conduit means upon development of a predetermined pressure in the packer, and means operable by the pump when in, its lower position, for releasing pressure in the packer to collapse I the packer.

8. An apparatus for testing fluid production in wells comprising a string of tubing, at least one in the outer sleeve and in fixed relation to the tubing, means for restraining movement of the intermediate sleeve with respect to the outer sleeve to rotary movement, an inner sleeve within the intermediate sleeve, means for restraining movement of the inner sleeve with respect to the intermediate sleeve to a vertical sliding movement, a perforate bottom closure for the inner sleeve, said three sleeves having orifices adapted to register in one relative position of the three sleeves whereby to establish communication for well fluids between the interior of the housing and tubing, and adapted to be put out of register by rotating the intermediate sleeve, to close the tubing while the apparatus is being lowered in the well, and also to be put out of register by depressing the inner sleeve, to close the tubing while the packer is being reset, conduit means leading from the interior of the packer and having a vent branch delivering outside the housing and a supply branch delivering through said 010- sure for the outer sleeve to the space between said closure and said perforate closure or the inner sleeve, a check valve in said supply branch, a valve in the vent branch and operating'means for the vent valve so constructed and arranged that upon depression of the inner sleeve said valve is opened to vent the packer.

9. A well testing apparatus comprising in combination a string of tubing extending down the well, a housing attached to the lower end of the tubing, a hydraulically expansible packer attached to the housing, a sampling tube in communication with the tubing and extendin through the packer into communication with the well below the packer, a guide sleeve within the housing in fixed relation thereto and provided with a base, an inner sleeve in telescopic sliding relation to the guide sleeve and constructed and arranged normally to remain above and away from the base, a conduit connection between the tubing and the interior of the packer, a valve in said conduit connection permitting flow of liquid from the tubing to the packer for expansion thereof, a vent duct delivering from the interior of the packer to a point outside the tubing, normally closed valve means in said vent duct, and opening means for said valve means extending up through the sleeve base and adapted for operation by said inner sleeve when moved down below its normal position toward said sleeve base. 35

10. A well formation tester comprising a string of tubing extending down the well, a hollow sleeve type hydraulically expansible packer carried at the lower end of the tubing, a fluid conduit extending from the tubing through the packer to a portion of the well therebelow, movable means in said conduit adapted in one position to open and in another position to close said conduit against flow of fluid from the tubing to the well, said movable means being provided with an actuating element projecting into said tubing, a removable operating member adapted to-be lowered through said tubing and adapted to engage and actuate said element, a duct connecting the expansible portion of the packer interior with the tubing above said movable means when in the closed position, a check valve in said duct opening toward the packer interior and packer vent means operable from the top of the well for venting the interior of the packer to the well.

, GEORGE W. RUSLER.

VICTOR V. VACQUIER.