US2124766A - Well tester - Google Patents

Description

July 26, 1938.

2 Sheets-Sheet 1 Filed March 20, 1937 W M m v Xm M AI. E 7 t 3 b m P 8 w. l w E I 9 3 m o 4 m fi \w t V///////7 /4/ A w 1 .r 2 O nu a A 5 RQ IIW a July 26, 1938. cox 2,124,766

WELL TESTER Filed March 20, 1 937 2 Sheets-Sheet 2 v 1,. III/l Ernest H.co

[III/III I III/I Patented July 26, 1938 UNITED STATES PATENT orrics WELL 'rss'raa, nest 11. Cox, Houston, Tex. Application rum-h so, 1931, Serial No. 131,995

8 Claims. (01. ass-1) My invention relates to well testers for the purpose of making a test of the productivity of the formation encountered in well drilling.

It is an object of the invention to provide a construction of well tester which will be operable through a single string of pipe or drill stem and which will be capable of positive action to open and close the interior of the tester to receive and then cut off a sample of the formation in which the test is made.

-I desire to provide a well tester which may be employed in connection with a hole of reduced diameter extended ahead of the main well hole, and ordinarily referred to as a rat hole, and to be operated by a down 11 pressure exerted upon the operating stem.

It is a further object of the invention to provide an eflicient means of sealing the tester against the entrance of fluid under pressure before the device is moved to open position.

It is a furtherobject of the invention to provide in connection with a tester of this character a means for introducing into the well bore a stream of flushing iiuiii when gas under pressure is encountered. i I I It is a further object of the invention to provide a chamber for the reception 'of a sample of the contents oi the well which may be held in I closed-position while the well is being filled with The invention resides largely in the particular construction and arrangement oi the parts making up my tester. I

This construction will be more clearly understood through reference to the drawings and description thereof which follows:

In the drawings, Fig. i is a side view of h;- tester showing the drill stem partly'in central lonm= tudinalsection.

Fig. 21s an enlarged longitudinal section showing the arrangement by which the flushing fluidmay be discharged into the well while the test is being made.

Fig. 3 is a transverse section on the'plane M of Fig. 2.

Fig. i is a broken detail taken on the plane t-t of Fig. 3 and showing a valve control discharge opening for the flushing fluid such as may be employed.

Fig. 5 is a central longitudinal section through the well tester.

Fig. 6 is a side view partly in elevation and partly in section illustrating the tester in open position.

Fig. 7 is a transverse section on the plane 1-! of Fig. 6; and r Fig. 8 is a similar transverse section on the plane 88 of Fig. 6. i

The construction of the sample receiving por- 5 tion of the invention is disclosed particularly in Figs. 5 to 8, inclusive. This device is adapted to p be secured to the lower end of a section of pipe I which may be drill stem or other pipe. The devce is connected to the drill pipe by means of a 10 coupling 2 of ordinary construction. The upper end ofv the tester comprises a nipple 3 threaded at its upper end for connection with the coupling and having its outer diameter increased to form adjacent the lower end a shoulder 4 against which the compression spring 5 may hear. The lower distance downwardly within the mandrel and is connected at its lower endwith the exterior thereof through lateral passages ill. The lower body ll oi the mandrel is reduced in diameter somewhat, as shown at l2 to allow 'the passage of liquid around the outside of the mandrel and between the same'and the outer sleeve 83.

The sleeve i3 is threaded within the lower end of a head it, said head being spaced from the v mandrel and having an inner recess to receive therings of packing is. Said rings are supported upon a shoulder in the head and are adapted to be compressed into sealing engagement with the outer surface oi the mandrel by means of a gland 40 it threaded within the upper end of the head it.

' The upper end of the head Hi forms a lower shoulder against which the compression spring 5,

previously referred to, may engage. I contemplate forming a protective housing ll about the spring by means of a sleeve of metal threaded at its lower end to the head it and projecting upwardly beyond the spring and along the outer surface of the nipple t and fitting slidably against said nipple.

The sleeve 63 extends downwardly from the head I for a suitable distance and has openings or perforations l8 adjacent the lower end through which fluid from the well bore may pass.

Above the perforated portion of the sleeve I is of flexible packing material spaced apart by rings 20 of metal or other rigid equivalent material. The lower one of the packing washers I3 issupported upon a downwardly tapered ring 2i, which is in turn supported upon a ring 22 screwed upon the outer surface of the sleeve l3. Itwill be noted that the outer surface of the head I is tapered downwardly and that the packing washers is are adapted to. be compressed against the inner wall of the rat hole, the tapered area of the head engaging within the upper portion of the rat hole, thus together forming a seal around the tester when it is in operative position at the bottom of the well.

At the lower end of the solid portion H of the mandrel I have screwed a cap 23, said cap having an upper shoulder at 24 which limits the relative downward movement thereon of the sleeve i3, the lower end of said sleeve being held against said cap by the spring 5 previously described. The lower end of the sleeve may have thereon a skirt 2! fltting slidably over the upper portion of the cap 23 and tending to prevent the entrance of sand or sediment thereto.

With the parts of the tester arranged as shown in Fig. 5 the passages Ill leading to the interior of the tester are closed by contact with the sealing rings it. when pressure is exerted upon the drill stem sufilcient to force the mandrel downwardly relative to the sleeve l3 the spring 5 will be compressed and the mandrel will be shoved downwardly into the position shown in Fig. 6, with the openings ll exposed below the packing rings. In this position fluid from the well may enter through the openings i3 in the sleeve and pass upwardly around the solid portion of the mandrel and enter the openings i0 and from thence pass upwardly through thepassages 3 and 3, and by raising the ball valve 29 may pass upwardly into the chamber 23 within the pipe or drill stem I.

It frequently occurs that when a. test of this kind is made there is found to be a pressure of gas in the well which tends to blow upwardly through the casing and to thus damage the well. To avoid this, it becomes necessary to pump mud downwardly into the well so as to weight down the gas within the well and carry away the aerated portion of themud into which the gas has entered. In order to accomplish this in connection with the tester and thus avoid dangerous blowouts I have provided means whereby the sample may be retained within the tester and drill stem and still allow the circulation of mud.

To accomplish this I provide a circulating head 21, .which is threaded at both ends for connection within the drill stem. This head comprises a heavy casting of metal having a central passage 28 therethrough, the lower end of which is partially closed by a plug 30. Said plug is screwed within the lower end of the circulating head and has a restricted bore 3| longitudinally thereof. Within the upper body of the head I form a plurality of downwardly extending passages 32. Said passages terminate approximate- 1y midway of, the length of the head and are connected with laterally extending branches 33 which discharge into valve chambers 34. As will be seen from Fig. 4, there is an outlet from the valve chamber 34 downwardly at an inclination as is indicated at 31 in that flgure.

Thisoutlet discharges to the lower side of the central enlarged portion of the circulating head 21. It will be seen from this construction that fluid pumped downwardly in the drill stem may pass through the passages 32 and 33 to the valve chamber and after passing the valve may be pro- Jected downwardly through the outlet 31 into the well casing 38.

Above the circulating head 31 I screw within the upper portion of the passage 28 an upwardly extending chamber or passage 39 upon the upper end of which is placed a standing valve preventing the entrance of liquid thereto from above. Said standing valve is of ordinary construction having a valve cage 40, an inner valve seat 4|, and a ball valve 42 in said cake and resting upon said seat.

It will be seen that when occasion arises to force mud down through the drill stem and into the well bore this may be done without interferw ing with the sample of the formation which has been taken. Fluid circulating downwardly through the stem will be shut oil from the tubular extension 33 by the standing valve and will be circulated outwardly into the well bore through the circulating head as described. The sample of formation which enters through the tester as described may pass upwardly past the lower ball valve 29 and into the chamber provided by the section of the drill stem i and the extension tube 33 above the circulating head. This chamber may be opened when the tester has been withdrawn from the well andthe sample of well fluid may be found retained within the chamber thus provided.

The advantage of my invention lies in the simple construction whereby the inlet to the receiving chamber is closely sealed, during the insertion of the device into the well, by means of the packing rings It. This chamber will, however, be opened to receive the well fluid by the relative'downward movement of the mandrel in the sleeve into position to expose the entrance openings It. When the test has been made the pressure on the device may be released by'moving the drill 'stem upwardly, thus automatically closing the further entrance of liquid to the receiving chamber.

There is the further advantage that fluid may be circulated into the well in case heavy gas pressures are encountered without interfering with the sample contained within the receiving chamber. I am thus enabled to make a satisfactory test and still be enabled to circulate where emergency arises so as to prevent a blowresponse to downward pressure on said string when said chamber is supported at the-bottom of the well, valves adjacent the upper end 'of said chamber to prevent downward passage 'of fluid therein, and means in said string to discharge flushing fluid from said string when said testing .means is being operated.

2. Means for testing the productivity of wells including a string of pipe, a chamber therein ineluding a section of said string and a standing barrel extending upwardly above said section, said chamber being normally closed at its lower end'butadapted to be opened to receive a sample of the well fluid in response to downward pressure on said string when said chamber is supported at the bottom of the well, valves adjacent the upper end of said chamber to prevent downward passage of fluid therein, and means in said string to discharge flushing fluid from said string when said testing means is being operated.

3. Means for testing the productivity of wells including a string of pipe, a chamber therein including a section of said string and a standing barrel extending upwardly above said section, said chamber being normally closed at its lower end but adapted to be opened to receive a sample of the well fluid in response to downward pressure on said string when said chamber is supported at the bottom of the well, an upwardly opening valve in said chamber, a circulating head in said string above said valve to direct flushing fluid from said string, a passage upwardly through said head and a standing valve at the upper end of said passage. 4. A well tester for use in a well having a hole of reduced diameter at its lower end, including a single string of pipe, a test mandrel at its lower end, an axial passage in said mandrel for a short distance at its upper end, the lower end of said mandrel being solid, a sleeve spaced slightly from said mandrel, there being openings from said passage to the interior of said sleeve and openings insaid sleeve, packing elements in said sleeve normally closing the openings in said mandrel, means holding said sleeve normally downwardly on said mandrel, a stop member on said mandrel limiting the downward movement of said sleeve thereon, a packer on said sleeve to engage the upper end of said reduced diameter well hole, said mandrel being movable by pressure relatively downwardly in said sleeve to move said openings below said packing to receive fluid from said sleeve.

5. A well tester for use in a well havinga hole of reduced diameter at its lower end, including a single string of pipe, 0. test mandrel at its lower end, an axial passage in said mandrel for a short distance at its upper end, the lower end of said mandrel being solid, a sleeve spaced slightly from said mandrel, there being openings from said passage to the interior 01 said sleeve and openings in said sleeve, packing elements in said sleeve 3 normally closing the openings in said mandrel, means holding said sleeve normally downwardly on said mandrel, a stop member on said mandrel limiting the downward movement of said sleeve thereon, a packer on said sleeve to engage the upper end of said reduced diameter well hole, said mandrel being movable by pressure relatively downwardly in said sleeve to move said openings below said packing to receive fluid from said sleeve, and a valve at the upper end of said mandrel to prevent the passage of fluid downwardly in said mandrel and sleeve.

6. A well tester including a single string of pipe, a perforated sleeve on the lower end thereof, a packer on said sleeve, a mandrel on saidpipe having a hollow portion with openings from the .interior to said sleeve and slidable in said sleeve,

means on said mandrel to limit the movement thereon of said sleeve, packing rings in said sleeve normally closing said openings, means to hold said sleeve resiliently downwardly to close said openings, an upwardly opening valve closing the upper end of said hollow portion, and means to discharge flushing fluid from said string ofpipe above said tester.

7. A well tester including a single string of pipe, a perforated sleeve on-the lower end thereof,

a packer on said sleeve, a mandrel on said pipe having a hollow portion with openings from the interior to said sleeve and slidable in said sleeve,

means on sald'mandrel to limit the movement thereon of said sleeve, packing rings in said sleeve normally closing said openings, means to hold said sleeve resiliently downwardly to close said openings, an upwardly opening valve closing the upper end of said hollow portion, means to discharge flushing fluid from said string of pipe above said tester, and a chamber in said string for well fluid between said valve and said flushing fluid discharge means.

8. In a well tester including a single string of pipe,'a testing chamber at the lower end thereof and means to close and open the lower end of said chamber, thecombination of a circulating head in said string above said testing chamber, said head acting to close the passage of fluid upwardly in said string except for a restricted axial passage, a tube extending upwardly from said passage, a standing valve thereon, discharge passages in said head for fluid from circulating head to the well.-

ERNEST H. COX.

above said 59

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