US2313762A - Automatic well test seal - Google Patents

Description

March 16, 1943. R. L. MIDGETT AUTOMATC WELL TEST SEAL' Filed Dec. 6, 1939 3 Sheets-Sheet l .ra f ffl asi March 16, 1943. R. L. MIDGETT hAUTOMATIC WELL TEST SEAL 3 Shee'ts-Sheet 2 Filed Dec. 6, 1939 All March 16, 1943. R. l.. MIDGETT AUTOMATIC WELL TEST SEAL Filed Deo. 6, 1959 5 Sheets-Sheet 3 ananullnlnanlllial. Juul III-l Patented Mar. 1s, 1943 UNITED STATES PATENT GFFICE I Y i 2,313,762

AUTOMATIC WELL TEST SEAL Rollie Lawrence Midgett, San Antonio, Tex.

Application December 6, 1939, Serial No. 307,910

5 Claims.

This invention relates to an improved automatic well test seal. Y

An object of the invention is to provide an automatic well test seal which will vrequire neither the installation of Well casing nor the removal of drill mud from the well hole, except at the strata being tested, for its proper operation.

A still further object of the invention is to vprovide an automatic well test seal which will be equally effective when sealing eithery a straight hole or one of irregular shape.

Another object of the invention is to provide a device of this class which automatically adjusts itself to well openings of different sizes.

Still another object of the invention is to provide a well test seal which will be safe, economical and highly efllcient in use.

Another object of the invention is to` provide an automatic well test seal employing an improved strainer which will be operative for preventing clogging of the suction or flow pipe.

And a still further object of the invention is toprovide an automatic well test seal which, in

into or removed from said Figure 10 is a side elevation showing the arrangement of Figure 9 with the flexible sleeves expanded.

Referring now more particularly to the accompanying drawings, wherein like numerals of reference will be seen to designate like parts its length. Heads 5 andv 6 normally close the body at its lopposite ends, said heads being of substantially cylindrical shape and being enlarged at their corresponding inner ends, as.

shown at 1 and 8. As will be observed the head 5 is formed with an eccentrically disposed port or bore 9 which is normally closed at its outer end by a plugl I 0. The head 5 is provided with an axial bore II which is'thread'ed at its outer end to receive the lower end of a suction pipe I2.

Figure 4 is a vertical sectional view ofthe device as it would appear in operative position in a well or test hole, the flexible body employed being shown expanded into contacting engagement with the wall of the well or hole,

Figure 5 is a fragmentary top plan view, on a reduced scale, showing the device. in the position assumed before expansion of the flexible sleeve,

Figure 6 is a transverse sectional view on the I line 6--6 of Figure 4,

Figure '7 is a transverse sectional view on the line 1-1 of Figure 4,

Figure- 8 is an enlarged detail sectional view of a portion of the strainer employed,

The inner end of the bore II is recessed and threaded to receive a hollow body member I3.

It will be seen in Figure 3 that the upper end of the sleeve 3 surrounds the flared portion 1 of the head. A ferrule I4 surrounds the upper end of the sleeve and retains said upper end of said sleeve in engagement with the outer face of said flared portion 1. A nut I5 is threaded on the outer half of the head 5 and engages the outer end of the ferrule I4. It will be seen that tightening of the nut I5 will shift the ferrule I4 inwardly, or downwardly, and thus clamp the upper end of the sleeve 3 tightly on the head 5. The head 6 is of somewhat similar construction to the head 5. However, said head diifers in construction in that it includes a recess I6 in which is mounted a tubular seat I1, said seat surrounding the upper end of an axial bore I8 which extends throughout-the length ofthe head G. The lower or outer end of said bore I8 is recessed to receive a packing bushing I9. The flared portion A8 of the head 6 is engaged with the lower end of the flexible sleeve 3 and is held in engagement therewith by means of a ferrule 20 which surrounds said lower portion of said sleeve.

The `ferrule 20 is forced into tight engagement with the lower end of the sleeve `by means of a nut 2| which is threaded on the lower end of the head 6. The nut 2|, as will be seen by referring to Figure 3, is recessed and internally threaded, at 22, to receive the upper end of a strainer pipe 23. It should be understood that the pipe 23 may be of any suitable length and may, if desired, comprise a number of lengths of pipe with the strainer portion located on the lower end. 'Ihe body member I3 is threaded near its lower end, as shown at 24. Secured at said threaded portion 24 is a stop sleeve 25 which is formed with an annular stop shoulder 26. The purpose of the stop sleeve 25 and stop shoulder 23 will be made apparent hereinafter.

At its lower end, the body member I3 is internally threaded to receive a guide member 21, said guide member being of smaller diameter than the body member I3. The guide member 2l is threaded at its lower end and has screwed thereon the upper or linner end of a stop sleeve 28. The stop sleeve 28 includes a sleeve portion 29 which is slida'bly engaged in the bore I8. 'The stop sleeve 28 includes a lower portion 30 and a stop shoulder 3l, said stop shoulder being, in operative position, in engagement with the packing bushing I9. throughout its length and cooperates with the guide member 2l and body member I3 for providing a continuation of the suction pipe I2. The lower end of the portion 3| is internally threaded to receive a lower section 32 of the suction pipe which lower section extends downwardly into the strainer pipe 23. As will be seen. the guide member` 21 is of less diameter than either the sleeveV 28 or the member I3. The purpose of this construction will be brought out during the course of the following description. It is also desired to point out that the lower end surface of the body member I3 and the upper end of the outer surface of the sleeve portion 29 of the stop sleeve 28 are tapered to define guide surfaces.

As seen in Figure 4, the strainer pipe 23 is provided with a guide bushing 33 which is lined with a resilient facing 34 to confrontv the section 32 of the suction pipe and thus provide centering means for said pipe within the strainer pipe 23. A spider 35 axially mounts the bushing 33 within said pipe 23.

Referring now to Figures 4 and 8 of the drawings, wherein the strainer pipe construction is shown in detail, it will be seen that said strainer pipe is formed by striking in end portions of said pipe todene inwardly disposed lips 3,6 and strainer openings 31. The strainer openings are formed in staggered relation to each other about the area of the pipe. 'I'he strainer pipe of my invention eifectually prevents clogging of the suction pipe, avoiding consequent impedance to continuous iiow. t

` In use, when the device is being installed in a well, the weight of thev suction pipe and the strainer pipe will cause the sleeve 3 to be extendedfto its full length, as shown in FiguresA 1, 2 and 3 of the drawings. In this position, the head 6 is held in its lowermost engagement with the packing bushing shoulder 3I of the stop sleeve. In order to prevent collapse of the sleeve 3, water lis poured therein through the opening 9, the plug IIl, of course, having first been removed and, after the space between the sleeve and body member has been filled with water, said plug I Il is replaced. When the device has been inserted in the well or test hole to the extent that the lower end of the strainer pipe 23 is in contacting engagement The stop sleeve 28 is hollow' I9 in engagement with 'the with the bottom of said well, supporting effort is removed from the portion of the suction pipe `member I3, the guide member 2l, and the stop .sleeve 28, with the pipe :I2-thereon, downwardly. from about the The head 6 will be displaced sleeve portion 29 of the stop sleeve 28. As this is done, the bore I8 will clear the upper end of the sleeve portion 23 so that a passage will be defined' between the surface of the bore and the outer surface 'of the guide member 21. Water or other liquid will be permitted to pass through this passage in either direction so that free movement of the flexible sleeve 3 will be per= mitted. As vthe head 5, with the body member, guide member and stop sleeve thereon, move downwardly, the head t will remain stationary and will'cause the sleeve 3 to expand to the po- .sition shown in Figure 4. That is to say, the

yflexible sleeve 3 will be expanded so that its outermost circumferential portion will' contact the surface of the well or test hole. As the lower end of the body member I3 engages in the tubular seat I'I located in the recess I 8 of the axial bore I8, the water passage from the inside of the flexiblesleeve 3 is closed. Further downward movement of the head 5 and the body I3 and the sleeve 25, by weight of the drill stem or of applied pressure, causes a hydraulic pressure inside of the flexible sleeve 3l, expanding the seal rmly against the inside of the well. When the annular stop shoulder 26 engages with the seat I'I, adoubly secure seal is effected and the excess weight of the drill stem rests on the sleeve 25 and the head 8. Liquid beneath the sleeve may then be drawn upwardly through the strainer pipe and suction pipe to the top of the well where it may be inspected for quality and, in addition, an estimate vmay be made as to the probable capacity of the strata in which the pipe 23 is resting.

When removing the device from the well after a, testing operation, upward pressure is exerted on the suction pipe. When vthis is done, the stop shoulder 3I on the sleeve 3Iliwill limit upward movement of the body I and, when the packing bushing I9 engages the stop shoulder 3|, liquid within the sleeve 3 will be retained in the sleeve 3 with said sleeve in a contracted position to facilitate extracting the' seal from the well or test hole. l

It is desired to call attention to the fact that the sleeve, being of flexible construction, will adjust itself to engage test holes having straight side walls or walls of irregular contour. Also it is desired particularly to point out that the expansion and contraction is automatic, being effected by resting the weight of the drill stem on the head of the seal while the strainer pipe is resting on the bottom ofl the well, or by releasing the pressure by lifting the pressure from the seal. In view of the fact that the mid-portion of the exible sleeve is reduced in thickness, as shown at 4, said mid-portion will expand rst, with the result that uniform expansion of the sleeve above and below said reduced portion will be assured.

It is also desired to call attention to the fact that the use of my improved sea. permits circulation of mud for iiooding strata tested before removing the. seal, and also the circulation of mud to float Sediment that might bind against seal while being extracted from the test hole.

tion shown in 4Figures 9 and 10, the numeral 38 indicates a well of any depth. Strata which is desired to be isolated is shown generally at 39. In thisembodiment of the invention, two of my improved seals are connected in.tandem; that is to say, one above the other in spaced relation. The seals are indicated by the numerals 40 and 4I and are each of identical constructionto that described with reference to Figures 1 to 8. The seals 40 and 4| are connected by a pipe 42 and a pipe 43, said pipe 43 having holesv 44 therein. A pipe 45 extends from-the lower end of the seal 4| to the bottom of the well, said pipe being of any determinate length. It is to be noted 4that no strainerpipe is employed with this ern-l bodiment of the invention. If it is desired to seal the strata 39 or to remove liquid therefrom, it is only necessary to remove lifting pressure from the lsuction pipe 46, which supports both of the seals in the well, when the sleeves of the seals will expand to the position snown in Figure l of the drawings. After this has taken place, liquid may be `forced through the openings 44 from the pipe 42 and into the strata 39. If itis desired to'removeliquid from the strata 39, without disturbing .the rest of the well, said liquid is forced outwardlythrough the openings 44, the pipe 42 and the pipe 46. It will be understood that the strata may be located at any point in A the wall. This embodiment of my invention may be employed for readily locating leaks in the casing of a finished well or forl the purpose of isolating a single strata at any depth. Also, when coupled in series (i. e. one above the other), the seals will be effective for isolating a single strata at any depth.

Having thus described the invention, what is claimed as new is: Y

l. In an automatic well test seal, a body including heads, one'of said heads having a body member, a guide member carried by the body member, a stop sleeve carried by the body member, a stop sleeve carried by the guide member, said lastmentioned stop sleeve receiving the other ofsaid heads in slidable engagement therewith, and a flexible sleeve extending about the body member,

4 the guide member and first-mentioned stop sleeve and being secured to each of said heads, said flexible sleeve and said first-mentioned head being shiftable downwardly for expanding the fiexible'sleeve to contact the inner surface of a well for sealing said well, said second-mentioned head engaging the first-mentioned stop sleeve when the flexible sleeve is in expanded position.I

2. In a device of the class described, a body including a flexible sleeve, heads' closing the exible sleeve at its opposite ends. said body having a body member therein and connected to one of the heads, a guide member connected with the body member, and a stop' sleeve connected with the guide member, said` stop sleeve having a sleeve portion slidably engageable in a bore in the other of said'heads, a suction pipe connected with thev first-mentioned head, and a strainer pipe connected with the other of said heads, said mst-mentioned headbody portion, guide member and stop sleeve being shiftable by the weight of the suction pipe for displacing the stop sleeve from the section-mentioned head and causing the flexible sleeve to expand to engage the surface of a well for sealing the well, said guide member defining a passage for liquid to and from the interior of the exible sleeve.

3. In an automatic well test seal, a flexible sleeve, upper and lower heads connected vwith the sleeve .at its opposite ends, means connecting the heads with the sleeve, said upper head being formed with an openingl for admitting liquid to the interior of the sleeve, the other of said heads being formed with a bore, a guide member carried by the upper head, a stop sleeve on the body member, aguide member carried by the body member and being of less diameter than said body member, a stop sleeve carried by the guide member and having a sleeve portion normally disposed'in the bore of the lower head, a suction pipe connected with the upper head, and a strainer pipe connected with the lower-head, said strainer pipe being normally engageable with the bottom of a well, said upper head, body member, guide member, and second-mentioned stop sleeve being movable upon release of supporting effort from the suction pipe whereby said secondmentioned stop sleeve will be disposedfrom the bore in the second-mentioned head and the first- .mentioned stop sleeve will be shifted to engage surface of a well for sealingsaid well.

4. In a device of the class described, a body including a flexible sleeve, heads closing the body at its opposite ends, one of said heads having means for permitting entry of liquid to within .the flexible sleeve, a suction pipe connected with one of said heads, a strainer pipe connected with the other of said heads, and means 4defining a passage for liquid from the flexible sleeve, said first-mentioned head being shiftable for expanding the flexible sleeve into contacting engagement with the wall of a well forsealing said well.

5. In a device of the class described, a flexible sleeve, heads closing the flexible sleeve at its upper and lower ends, a suction pipe connected with the upper head, a strainer pipe connected with the lower head, a body member carried by the upper head, said upper head having an open-1 ing to permit flow of liquid to within the flexible sleeve, a stop sleeve on the body member, a guide sleeve on the body member, said lower head having a bore and said bore being recessed at its opposite ends, a tubular seat on the upper end of said bore, a packing bushing on the lower end of said bore, said guide member being of less diameter thanthe body member and cooperating with the bore in the lower head to define a liquid passage to and from the interior of the flexible sleeve, and a stop sleeve carried at the lower end o f the guide sleeve and including a sleeve portion and a stop shoulder, said sleeve portion of the

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