US2094022A

US2094022A - Retrieving sand tester

Info

Publication number: US2094022A
Application number: US57329A
Authority: US
Inventors: Pennington Harry
Original assignee: Individual
Current assignee: Individual
Priority date: 1936-01-03
Filing date: 1936-01-03
Publication date: 1937-09-28
Anticipated expiration: 1954-09-28

Description

Sept. 28, 1937. H. PENNINGToN 2,094,022

RETRIEVING SAND TESTER Filed Jan. 5. 1956 3 Sheets-Sheet 1 5 Sheets-Sheet 2 Sept 28, 1937. H. PENNINGTON HETRIEVING SAND TESTER Filed Jan. s. 195e Sept. 28.1937.

H. PENNINGTON RETRIEVING SAND TESTER 5 sheets-sheet 3 Filed Jan. 3. 1936 Patented Sept. 28, 1937.` d v K iiNlTED STATES PATENT @FFICE RETRIEVING SAND TESTER Harry Pennington, San Antonio, Tex.

Application January 3, 1936, Serial No. 57,329

27 Glaims. (Cl. 166-1) My invention relates to sand testers such as means for latching the testing device firmly in are now employed in making a test of the formaposition While the test is being made. tion at the bottom of the well to determine wheth- Further objects include the control of the cirer or not productive sand has been reached. culation through the drill stem and the tester In prospecting in particular, and of course in so that the well may be washed and the drill stem 5 development of a discovered iield, or in drilling and drill bit rotated while the test is being made, wells to a lower depth in search of production so that there will be no danger of caving in of the in lower horizons, a current method is to run a formation due to a stoppage of circulation. small hole ahead of a large hole in order to leave It is a further object of the invention to proa shoulder on which to set casing, should provde a device of the character stated which will 19 duction be discoveredy in the small lower hole enable the pilot hole t0 be drilled Previous t0 the called the rat hole. making of the test also without withdrawing the In many operations the method of doing this is drill stem, the pilot drilling mechanism being conto core drin in a rat hole during the dayand to structed on the same plan as my well testing ream down at night, leaving a full gauged hole device. 15

to bottom, ready for the next crew to begin rat- Further objects and advantages of the invenholing or core drilling in daylight. The core obtion will bemore clearly understood from the tained in the rat hole operation gives the driller- Specioation taken with the drawings herewith. an accurate log of the well and also gives him In the drawings. Fig. 1iS a Central lonitlildrlalV an indication of when oil or gas formation is Section through a drill stem equipped to handle reached, l my invention, the upper end of the testing device In any event, a shoulder is necessary on which being shown partly in elevadon and Partly in to set casing ln order to develop production found longitudinal Section. A

below in a rat hole, for the rat hole made in core Fig. 2 is a similar view disclosing the lower end' drilling is usuauy of such a diameter as to ieave of the drill stem and tester Shown in position 25 a shoulder at the bottom of the full sized hole on Preparatory for making a tesi?- which casing can be set. For example, when set- Fig. 3 is a transverse section on the Plane 3-.3 ting 7" OD casing the rat hole made by the 0f Fig. 1.- coring bit may be 6%" in diameter and the full Fig. 4 is a similar transverse section on the hole diameter may be 97/8". In this rat hole a plane 4-4 of Fig. 2- 30 test is made by introducing a testing device. Flg- 5 iS a Seelion through the Well bore show- The tester includes means to pack off the upper ing a drill Stem having oonstriotions therein end of the rat hole to prevent fluid from above through Which the Well.i1eSi7eriS Shown aS Passingentering the same and a closed chamber in the Fig- 6 iS a Similar View of the lower end of the y lower end of the tester may be opened when drill stem showing the drill bit with the tester in seal with the rat hole is accomplished so as to Position above its Seat in the drill bit.

receive a sample of the formation in the rat hole Fig- 7 iS an enlarged View Similar to Fig- 6 below the packen The chamber may be vthan but showing the tester in operative position to closed and the tester withdrawn from the hole. take a Sample ofthe formation.

It is an object of my invention to provide a testing device and methods of operation whereby tests of this character may be made, said device being capable of use while the drill stem and well bore with the drill stem therein equipped to operate with my core drill; andv Fig. 9 is a view of the lower end of the 'drill stem and bit. with my retrieving core barrel Vin Fig. 8 is a longitudinal section through the 40 drill are still 1n the hole. I desire to make tests .position to drm the pilot hole ahead of the mam. 45 I of the formation without the necessity of withf l drawing the drill stem and bit which are emv poggnhoglslr'nd 6 Ihave Shown a We Ployed m drilling into the formation- 1 bore equipped for a portion of its length withA a It 1S arloilierellileet '00 Provide a detached test' well casing I, the lower end of which has been lng device whlch can be circulated dOWn and sealed by the usual cement 2 into close contact 50 latched into Position t0 take al Sample 0f iShe with the formation. The well bore 3has been exuid from the formation and, yafter taking such tended downwardly below `the casing and, as samples, to be returned again to the surface by shown in Fig. 6,v a pilot bore or rat hole v64 has the circulation of the liquid employed in drilling been vdrilled 'down into what; is believed to be a` It is another object to provide a.releasab1e producing formation.. y

CSI

The drill stem 5 may be of ordinary construction having tool Joints connecting the sections thereof together. I have shown pipe sections the ends of which are upset internally and threaded on the outside to engage with couplingsl, which secure the ends of the sections together. There is thus provided at each of the Joints a passage 'I which is somewhat more constricted than the portion of the drill stem section between the ends.

At a point spaced above the lower end is a special nipple or coupling 8, which has the constricted inner portion thereof provided with downwardly extending ratchet teeth 9.

At the lower end of the drill stem is a core bit Il having radial cutting blades II thereon to cutl the formation. The interior ofthe bit head is provided with a downwardly tapered seat I2 for the testing device. Above the seat I2 is a cylindrical area I3 adapted to fit closely with the tester, as will be later noted. Downwardly di rectedpassages 4 in the head connect vwith this cylindrical area to provide an outlet for the flushing fluid passing downwardly through the stem when the tester closes the core opening. Above the cylindrical area the interior of the head is widened out at I4 to provide a chamber for the passage of the fluid.

' My tester is adapted -to be moved downwardly through the drill stem by fluid circulation. It includes an upper latching section formed within a housing I5 shown best in Fig. l. This housing is a tubular barrel and at the upper end thereof is a tubular bushing I6, the outer surface of which is tapered upwardly. An inner groove I9a is provided into which a spear may engage if it is desired to remove the tester by wire line means. Said bushing is threaded into engagement with the upper end of the housing and its interior provides a cylinder into which the upper extension I1 of the plunger may ilt. The lower end of the housing is connected with a short nipple I8, which is threaded at its lower end for engagement with the lower bushing I9.

` Within the housing I5 is the plunger which operates the latching device. This plunger has a body 20, the outer surface of which is formed with opposite downwardly and inwardly inclined track-ways 2l, the outer surfaces of which are formed with tenons engaging within mortises in the inner faces of wedge shaped latching dogs 22 tting through openings in the housing. The connection between the dovetailed tenons and the latching dogs allows a longitudinal sliding movement of the dogs on the track-way provided on the outer surface of the plunger so that when the plunger is moved relatively downward the dogs will be pushed outwardly and the teeth 23 on their outer surfaces will engage with the teeth 9 in the drill stern coupling.

The plunger body 20 is hollowed out from its lower end upwardly to a point adjacent the extension I1. From the inner chamber 24 thus provided there are lateral fluid passages 25 leading to the interior of the housing. Flushing fluid `is thereby allowed to pass downwardly from the drill stem around the upper end of the plunger and through the openings 25 to the interior passage 24.

The housing has lateral slotted openings through which the dogs 22 may move and it will be noted that the dogs fitting within these openings are prevented from longitudinal movement in either direction relative to the housing. The

lower end of the plunger is provided with a nut 26 having an upper radial flange 21 engaging closely within the nipple I9 previously noted. Below the nut 25 is a compression spring 23 which bears at its lower end upon the bushing I9 and at its upper end upon the flange 21, thus tending to hold the plunger 20 in its elevated position with the dogs withdrawn. withinr the housing.

The bushing I9 has a lateral outlet port 5l allowing Ailuid from the interior of the housing to pass' outwardly into the space 29 between the tester and the drill stem. Said bushing has its lower end reduced in diameter and an annular `nut or ring-39 is screwed thereon.' This ring serves as a support for an anti-friction bearing 3I upon which is supported a lower sleeve or housing 32. Said sleeve has a nut 33 screwed on the inner upper end thereof'above a ring 34 which rests upon the bearing race. -It will thus be seen that the bushing I9 may be rotated relative to the sleeve 32 because of the swivel connection thus provided.

The sleeve 32 is connected at its lower end to a second sleeve 35 by means of a plate 36 which closes the interior of the two sleeves and also serves to connect them together, said plate being welded at 31 into connection with the two sleeves. The lower end of the sleeve 35 has an inner collar 38 which is in turn connected with the inner test tube 39 to which it is welded at 40.

The tube 39 is extended downwardly and telescoped within the packer sleeve 4I.` The lower end Ioi' the tube is welded into `connection with a reduced extension 42 on the tube which projects downwardly below the packer sleeve and has at its lower end an annular nut 43, which projects from the outer surface of the tube and acts as a stop member, as will later appear. The extension 42 closes the lower end of the tube against entrance of fluid thereto from below.

The packer sleeve is of greater thickness at its upper end and is tapered at 44 to engage within the seat in the rat hole and form a frictional seal therewith. The upper end of the packer sleeve has a lantern or cap 45, the upper end of which is directed inwardly and fits closely about the test tube. A plurality of packing rings 46 within the cap makes a close seal with the test tube so that no iluid can pass at this point. Below the packing rings is a metal ring 4l having openings therethrough which register with openings 48 in the cap 45 whereby fluid from the interior of the drill stem can pass through to the exterior of the test tube. A longitudinal channel is provided on the outer surface of the test tube by externally 'formed grooves 49 therein, said grooves running vertically along the outer surface of the tube to a point indicated at 50 where the fluid may issue into the chamber 5I formed in the lower end of the packer tube. The fluid may pass then from the chamber 5I through openings 52 in the test tube extension 42 below the closed lower end of said tube, and from thence downwardly out the lower end of said extension.

The lower end of the packer sleeve is closed about the extension 42 by means of an inner nut end and the nut 43 on the test tube a spacing sleeve 54. 'Ihe test tube has inlet openings 55 at opposite points within the packer sleeve, as shown in Figs. 2 and 4, said openings being normally out of registration with similar openings 56 in the packer sleeve 4I. Said packer sleeve is held downwardly on the test tube with these openings out of registration through means 0f a Aor sleeve 53, said sleeve having between its lower spring 51, which, as shown in Fig. 2, separates the lower end of the latching mechanism from y the testing device.

It is to be noted that the length of my tester is sufficient to extend from one joint in the drill pipe to anotherjoint, so that it can bemore effectively acted upon by the ilushing fluid.

When the rat hole has been drilled ahead ready to make a test as shown in Fig. 6, the testing device may be introduced at the upper end of the drill stem and circulated downwardly by the flushing iiuid to engage within its seat in the interior of the drill bit I0. While it is thus being moved downwardly the fluid will pass through the drill and upwardly in the well bore outside ofy the drill stem. When the testing device first engages through the bit and within the upper end of the rat hole, as shown in Fig. '1, the circulation will be cut off through the central opening and will pass out through the lateral outlets 4. 'I'he drill will be raised from the bottoni of the hole and the pressure of the pumping Vfluid upon the piston I1 will tend to move the testing tube downwardly into its seat in the drill bit and when this is accomplished the plunger will move relatively downward and expand the.

latching dogs 22 into locking engagement with the drill stem. This will prevent the testing device from being moved upwardly during the testy ing operation.

When the testing device is thus seated in the bit, as shown in Fig. 2, the circulation outwardly Lio . ings 56 in the packer tube and allow the materialin therat hole to enter into the testing device, and pass upwardly in the test tube. If the ma- The lowering of the weight of the drin stem on the tester will then cause the upper latching portion of the tester to move downwardly relative to the test tube and this relative downward movement will compress the spring 51 and allow the tube to be moved to its lowest position where the openings 55 therein register with the openterial in the hole is under pressure of gas the pressure will surge into the device and by compressing any air which is present will ll the chamber below the partition 36 and above the closed end 42 of the tube extension with a sample of the well fluid. The outlet through the passage 49 will be closed against escape of iiuid'from the rat hole due tothe previousl downward movement of the test tube relative to the packer sleeve which brlngsthe upper end of the channel49 away from the opening 48 and thus leaves a closed rat hole.

When the sample has been taken in'this manner the drill stem is again raised olf the bottomv to relieve the pressure on the testing device to close the chamber 39a and the circulation of` iiuid in the hole is reversed, the fiuid flowing down on the outer side of the drill stem and up through the insidethereof, carrying with it the testing device with its sample to the surface. The upward flow of fluidwill engage below the piston 20. moving the piston upwardly relative to the latching dogs into the bushing I6, and thus withdrawing said dogs and releasing the locking engagement of the testing device with the drill stem.

The raising of the drill stem to release the pressure through the spring 51 upon the packer sleeve will allow the test tube to move upwardly in the packer sleeve and open the passage through the channel 49 so that circulation may take place around the test chamber. The openings 55 will move out of registration with the openings 56 and will be sealed against the entrance of uid to the test chamber.

When the testing device is removed from the upper end of the drill stem tests may be made of the amount of pressure in the test chamber and the contents of the chamber may be examined to determine whether production is present.

In Figs. 8 and 9 I have shown how the rat hole may be drilled ahead by attaching a core drill at the lower end of the housing 58 similar to the housing of the testing device. The same latching mechanism may be employed to latch this housing to-the interior of the drill stem after the housing has been pumped downwardly into position in the drill stem. I contemplate securing to the forward end of the housing a core barrel 59 adapted to project in advance of the bit and to drill a pilot hole of the desired depth in advance of the main bit. The particular construction of this core bit is not a part of the present invention and need not be further considered. It is to be understood, however, that by the use of a core barrel of this character the pilot hole can be drilledi and thetest made without withdrawing the drill stem and bit from the hole. The coring apparatus is capable of being pumped upwardly out of position after the rat to cave in. 'I'he making of atest thereafter becomes impossible until the well is again cleared of HoweverI with my construction theA material. drill stem and drill bit remain in the hole and rotation ofthe drill stem and circulation of the flushing fluid may continue throughout thetesting operation. Thus I not 'only economize in time in making a test but I'provide against caveins or similar difficulties by the vcontinuing of rotation and circulation during the operation. It'` is also evident that afterthe test is completed the drill stem with the tester in position therein may be removed. This method is much less economical of time, however. vThe further advantages will be obvious to those skilled'in the art.

What is claimed as new is:

1. A method of testing a formation encouri-v tered in drilling wells having a drill stem therein, vincluding moving a `closed chamber downwardly through said drill stem to a position projecting ahead thereof, circulating flushing fluid about said chamber to wash the well, sealingl the well about said chamber to close oentrance of fluid from above to said chamber and the lower end of the well, opening said chamber-below the point of said sealing and receiving a sample of the well iluid from the formation to be tested,

. formation to be tested, closing said chamber, and

retrieving said chamber upwardly to the surface leaving the drill stem in the well. l f' 3. A method of testing a formation encountered in drilling wells, havinga drill stem therein, including moving a closed chamber downwardly chamber, unsealingabout said chamber to permit circulation of flushing fluid to the well bottom, and retrieving said chamber upwardly to the surface leavingthe drill stem in the well.

4. A method oi testing a formation encountered in drilling wells having a drill stem and drill therein. including moving a closed chamberv downwardly through said drill stem to a position projecting ahead of said drill, circulating flushing fluid about said chamber to .wash the well, sealing the well about said chamber to close off entrance of fluid from above to said chamber to the lower end of the well, opening said chamber below the point of said sealing and receiving a samplel of the well fluid from the formation to be tested, closing said chamber, and forcing said chamber upwardly to the surface by the circulation of liquid outside said drill stem into the lower end thereof, leaving the drill stem and drill in the4 well.

5. In a well having a drill stem and drill therein, the method of obtaining a sample of fluid from the formation at the well bottom including moving a closed chamber by fluid circulation downwardly through the drill stem and drill to the well bottom, sealing the well above the lower end thereof, opening said chamber at a point below said seal to receive a sample of fluid, closing said chamber, unsealing the lower end of the well, l

- therein, the method of obtaining a sampleof 60 fluid from the formation at the well bottom, including moving a closed chamber by fluid circulation downwardly throughv the drill stem and drill to the well bottom, sealing the well above the lower end thereof, opening said charnber at a point below said seal to receive a sample of fluid, closing said chamber, unsealing the lower end of the well and circulating liquidupwardly through the drill and drill stem andv causing the upward flight of said chamber to the surface.

7. In a well having a drill stem andA drill therein the method of obtaining a sample of fluid from the Aformation at the well bottom compris- Yposition in the lower end of said drill, circulating liquid around said tester to wash the well, forming a seal about said tester to close 'off the well above the lower end thereof, opening the chamber below said seal to receivea sample of fluid,

closing said chamber, and removing said cham- `ber with said sample.

8. In a well having a drill stem and drill ltherein the method of obtaining a sample of fluid from theformationy of the well bottom comprising, moving a tester having a closed chamber downwardly through the drill stem to a sealing position in the lower end of said drill, circulating liquid around said tester to wash the well, forming a seal about said tester to close off the well i above the lower end thereof, opening the chamber below said seal to receive a sample of fluid, closing said chamber, releasing said seal, raising and rotating said drill and circulating fluid downwardly about said drill stem and upwardly therethrough to carry said tester to the surface.

9. In a well havinga drill stem and drill therein, the method of obtaining asample of fluid from the formation at the well bottom, comprisling moving a closed chamber by liquid circulation through said drill stem and drill to the botclean the'well, rotating the drill stem and, while rotating, sealingoff the entrance of fluid from above the lower end of the well, opening the said chamber below the point of sealing to receive a sample of fluid, closing said chamber, raising said drill stem and unsealing the said lower end of the well, and circulating the flushing fluid upwardly through the drill stem to carry said chamber to the surface.

l0. In a well having a drill stem and drill therein, the method of obtaining a sample of fluid from the formation at the well bottom, comprising moving a closed chamber by liquid circulation through said drill stem and drill to the bottom of the well, washing about said chamber to clean the well, rotating the drill stem and, while rotating, sealing off the entrance of fluid from above the lower end ofthe well, opening the said chamber below the point of sealing to receive a sample of fluid, closing said chamber and employing the circulation of flushing fluid to raise said chamber to the surface.

|11. In a well having a drill stem and drill therein, the method of obtaining a sample of fluid from the formation at Athe well bottom comprising, leaving the drill stem in the well, drilling a small pilot hole ahead of the hole cut by said drill, lowering a tester having a closed chamber to the bottom of the well, washing about said tester to clean said pilot hole, extending said tester into said hole, sealing about the upper Aend of said pilot hole, opening said chamber to receive av fluid sample, closing said chamber, raising said drill stem to break said seal, and then circulating said tester back upwardly through said drill stem to the surface.

l2. In a well having a drill stem and drill therein, the method of obtaining a sample of fluid from the formation at the well bottom comprising, leaving the drillV stem in the well, drilling a small pilot hole ahead of the hole cut by said ldrill, lowering a tester having a closed -chamber to the bottom of the well, securing said tester against upward movement relative to said drill stem, washing about said tester to clean said pilot hole, extending said tester into said hole, sealing about the upper end of said pilot hole, opening said chamber to receive a fluid sample,

4'0 be moved through said drill stem, including an closing said chamber, raising said drill stem to break said seal, and then circulating said tester back upwardly through said drill stem to the surface.

13. In a well having a drill stem and drill theretester to clean said pilot hole, extending said tester into said hole, sealing about the upper end of said pilot hole, continuing fluid circulation in the well above said seal and manipulating said drill stem to open said chamber below the seal, closing said chamber, :raising said drill stem to break said seal, and then circulating said tester back upwardly through said drill stem to the surface. v A

14. In a well having a drill stem and drill therein, the method of obtaining a sample of uid from the formation at the well bottom comprising, leaving the drill stem in the well, drilling a small pilot hole ahead of the holecut by said drill, lowering a tester having a closed chamber to the bottom of the well, securing said tester against upward movement relative to said drill stem, washing about said tester to clean said pilot hole, extendingsaid tester into said hole, sealing about the upper end of said pilot hole,

continuing iluid circulationin the well above said seal and manipulating said drill stem to open said chamber below the'seal, closing said chamber, raising said drill stem to break said seal. and then circulating said tester back upwardly through said drill stem tothe surface.

15. An apparatus of the character described comprising a drill stem, a core drill thereon having a tapered seat therein, a well tester free to upper latching device, radially positioned latching dogs therein,hydraulically-operated means to extend said dogs to engage said drill stem, a testing tube below said latching device, a samplereceiving chamber in said tube having lateral inlet Vopenings therein, a packer sleeve on said tube normally closing said openings,y said tube being adapted to be moved by said drill stem downwardly relative to said packer sleeve to open said inlet openings to receive` a sample of fluid from,l the well, said' latch being acted upon by` upward circulation offluid in said drill stem to release saidtester and allow said tester to be elevated by fluid pressure tothe surface.

16. An apparatus of the character described vcomprising a drill stem, a core ldrill thereon hav- .ing a tapered seat therein, a well tester free to be moved through said drill stem, including an upper latching device, radially positioned latching dogs therein, hydraulically-operated means to extend said dogs to engage said drill stem, a testing tube below lsaid latching device, a swivel connection between said latching device and said tube, a sample-receiving'chamber in said' tube having lateralinlet openings therein, a packer sleeve on said tube'normally closing said. openings, said tube being adapted to be moved by said drill stem downwardly relative to said packer sleeve to open said inlet openings to receive a. sample of fluidfrom the well, said latch being acted upon by upward circulation of fluid in said drill stem to release said testerA and allow said tester to be elevated by uid pressure 4to the surface.

17. A drill stem, a core drill thereon, a seat in said drill, a well tester unit adapted to be moved downwardly from the surface through said drill stem and seal in said seat, hydraulically operated means to latch said tester unit in said seat, means to seal oi the lower end of the well,

, means to take a sample of the well fluid below said seal, said latch being released and said unit being carried upwardly in the drill stem by an upward circulation of liquid in the drill stem.

' 18. A drill stem, a core drill thereon, a seat in said drill, a well tester unit adapted to be moved downwardly from the surface through sad drill` stem and seal in said seat, hydraulically operated means to latch said tester unit in said seat, a

closed test tube at the lower end of said unit, said same, said unit being releasable for movement upwardly in said drill stem by an upward circulation of liquid in said drill stem.

19. A drill stem, a core drill thereon, a seat in said drill, a well tester unit adapted to be moved downwardly from the surface through said drill stem and'seal in said seat, hydraulically operated means to latch said tester unit in said seat, said latch including radially positioned dogs toothed to engage the drill stem, a piston movable downwardly relative to said dogs to move said dogs into locking position, a closed test tube at the lower end of said unit, said tube being rotatable relative to the upper portion thereof, means on said tube to seal with the walls of the well, means toopen said tube below said seal to take a sample and then to close the same, -said unit being releasable for movement upwardly in said drill stem by an upward circulation of liquid in said drill stem.

20. A well tester for use with a drill stem and drill including a freely movable unit adapted to fit slidably through the joints of said drill stem and be moved therein by uid pressure, to a seat in said drill, means to open up a passage for vfluid past said unit into the well bottom for flushing the same, means to latch said unit in said drill stem, said passage being closed by downward pressure of said drill stem, means to seal off the lower end of the well, said tester being opened up to receive a sample of fluid below said seal by said downward pressure, said drill stem being rotatable while said sample is being taken, and means to close said unit and move it back upwardly in the drill stem responsive to uid circulation.

21. In drilling a well with a rotary drill stem having a core drill thereon, the method of sampling the formation being drilled without removing said drill stem including; drilling a small pilot hole ahead of thefmain hole, washing said pilot hole, introducing a closed testing chamber into said pilot hole, sealing about said chamber at the upper end of said pilot hole, opening said chamber to receive a sample, closing said chamber and removing the same upwardly through drilled without removing the drill stem and core drill including, washing the lower end of the well, forming a seal with the walls of the well adjacent the lower end of the well, rotating said drill stem and continuing the circulation oi' ilushing iiuid and simultaneously removing a sample of the fluid below the point of sealing.

24. In a method of testing the production oi an earth formation at the bottom of a drilled hole, the steps of lowering a pilot bit into a core drill, latching said pilot bit in place with its lower end protruding beyond said core drilla predetermined distance, drilling a rat hole" into the formation with said pilot bit, withdrawing the pilot bit, lowering into said core drill a sample taking device including a closed receptacle adapted to receive a sample of the production, latching said device in place with a part projecting into said rat hole, sealing oi! between said part and the wall of said "rat hole, opening communication between said receptacle and said sealed o space to receive a sample oi' the production from said rat hole, sealing the receptacle, and withdrawing-the sample taking device from the core drill with the sample therein.

25. In a method of testing the production of an earth formation at the bottom of a drilled hole, the steps of lowering a pilot bit into a core drill, latching said pilot bit'in place with its lower end protruding beyond said core drill a predetermined distance, drilling a rat hole into the formation with said pilot bit, withdrawing the pilot bit, lowering into said lcore drill a sample taking device including a closed receptacle adapted to receive a sample of the production, latchlng said device in place 'with a part proand maintaining circulation of washing nuid throughout the process.

26. In a'core drill device for taking a sample of the production of an earth formation, a iluid sample receptacle to be lowered into a core drill, means connected with said'receptacle to project below the lower end of said core drill and to be lowered into a hole in thevformation, means on said receptacle above said last mentioned projecting means for s ealing oi the bottom portion of said hole, means normally closing said receptacleagainst ingress of any outside substance, means for opening said receptacle to communication with the hole below said sealing means when said sealing means is set, and latching means for latching said receptacle in position within the core drill.

27. A method of obtaining an indication of the pressure occurring in a well bore in an earth formation, which comprises the steps of lowering a closed receptacle into the well bore, through the drill stem therein sealing the well bore about said receptacle below the drill, opening the receptacle to receive the formation at formation pressure, closing the receptacle to retain the pressure of the formation, and raising the receptacle through the drill stem to the surface to ascertain the pressure.

HARRY PENNINGTON.