US2661802A - Combined shut-in and back circulation tool - Google Patents

Description

Dec. 8, 1953 M. o. JOHNSTON 2,661,802

COMBINED SHUT-IN AND BACK CIRCULATION TOOL Filed March 9, 1950 2 vSheets-Sheet 2 1N V EN TOR.

Bye/9a@ am Patented Dec. 8, `1953 4v2,661,802 'oormINEDjsHUT-'I'N AND "BACK CIRCULATION `TOL Mordica 0. Johnston, Glendale, "Calii, assigner,

wb'y mesne assignments, 'to Johnston Testers, Inc., Houston, Tex., a corporation of Delaware ApplicationMarch 9, 195D,"Serial"o. ilfl' 4 Claims. 1

This invention relates to an oil well tool and particularly pertains to a combined :shut-"in Fand back circulation tool.

In oil well drilling operations -it is common practice to pack off the well bore at a `"desired level and obtain an entrapped sample of 'fthe formation iiuid yield by the use of fa Iformation tester. In this operation it is 'desirableto make a test to ascertain the fluid pressure exerted vby the connate fluid in vthe formation and it is Aalso desirable to produce 'a back circulation of the drilling uid within which the testing tool is 'submerged. A tool vfor these purposes should be 'associated with the tester and disposed 'between the retaining valve structure of the tester and the trip valve which occurs atthe l'ower-end-of a supporting string of pipe. It is the principal object of the present invention therefore ito provide a valve structure which may be manipulated from the surface of fthe well through the supporting string o1" pipe and by which the connate fluid passing through the `tester 4may be shut 1in to obtain a desired iiuid pressure reading .after the test is 'made or whichstructure Vmayb'e inanipulated to perform `a back vscuttling Vactionin the well for emergency purposes and to allow fthe drilling fluid to enter the tool above 'the comfiate iiuid therein.

The present invention contemplates the provision of a tubular housing interposed between the retaining valve and trip valve 'of a formation tester and which tubular housing may be manipulated to permit connate fluid to owt-hrough Athe tester and above the retaining valve where it is restrained and to thereafter now upwardly into the drill pipe when the trip valve is opened,`

said structure embodying the use of a back scuttling valve carried within the tubular housing and capable of manipulation to establish communication between the interior of the shut-in valve structure and the well bore whereby drilling fluid may enter the valve structure when desired.

The invention is illustrated by 'way rof 'example in the accompanying drawings in which:

Figure 1 is a View in elevation showing 'the application of the present Vinvention to the usual formation tester assembly.

Fig. 2 is an enlarged fragmentary View in 'longitudinal section vas seen on the line 2-"2 of Fig. 1

and 'shows the construction of the Vupper 'section vorally indicated in Fig. 1 at i5.

has a threaded connection with the housing of a trip yvalve'structurel l. The trip valve structure is formed at its lower end with a 'pin v"i2 which extends into a boX I3 of a sub lf'l which forms a 'part of the 'combined shut-in valve and lback V'scuttling kvalve with which theV present invention 'is particularly concerned and which valve is `gen- The sub It has a-central passageway l5 through itA which terminates in Va threaded counterbore il. The lower end of 'the sub is reduced in diameter as indicated a-t |98 and is externally threaded at i9 to 'receive "an adjusting cap 2t. Threaded into the bore -Il andextending downwardly-from the vsub is the upper tubular mandrel section 2i. Near the upper end of the mandrel section 2i and -below its threaded 4portion is "a shoulder 22 against which the lower end 'of the adjusting cap 26 abuts. The lower end `oi the mandrel 2| is Vformed with an internally 'threaded counterbore '23 to receive the upper threaded end of the VVmain vsection 24 of the tubular mandrel. The upper section 2l of the tubular mandrel has a central bore 2'5 and the lower "section has a central`bore r2li longitudinally aligned therewith and extending entirely therethrough. Mounted Vupon "the main section 2'4 is a ball thrust bearing 2l, the upper race 28 Aof which provides a seat for a collar `compression lspring 2'9, the 'upper end of 'the vcompression spring 29 resting against the lower face 'or the adjustable cap 2G. The thrust bearing has` a lower 'race 30 which `rests against the upper f'ace of a .split collar V'31. The parts 'of this collar .are held together by clamping bolts 32. The collar rests against the end face of the upper section 3'3 'of a. tubular housing which is formed at its lower end `with 'a threaded pin 3Q to extend within a "threaded `lbox 35 of an intermediate housing section V36 carrying a sliding nut 3l. lThe nut 31 is cylindrical and lits Within ka central 'bore 38 oi "the vvintermedia'te housing section 36. This nut is formed with an internally threaded bore 39 comprising acme or other type coarse threads and receives threads fall formed upon a length of the main tubular mandrel section 24. The main tubular mandrel section is formed with a collar il which in its upper position abuts against the lower end face of the pin 34 of the upper tubular section 33. Directly above the collar and extending radially from the mandrel are lugs 42 which in their uppermost position register with keyways 43 cut into the inner wall of the upper housing section 33. The

upper end of the housing section 33 is formed.l

with a counterbore 44 to receive packing 45 which circumscribes the mandrel 24 and is held in position by a stuing gland 4G threaded into the upper end of the counterbore d4 and through Y which the mandrel 24 extends with a substantially tight iit. The threaded section 39 of the nut is relieved at its lower end so that a clearance opening il will occur within the nut and below the lower end of the threaded section 39. Communicating with the cylindrical bore 41 within the nut 37 is a threaded bore i8 which receives a perforated mandrel section 49. This valve section has a central longitudinally extending passageway 59 through which fluid may ow. The walls of the tubular valve section of the perforated mandrel section 49 are formed with radial ports l for a purpose to be hereinafter described. The lower end of the mandrel section 49 is fitted with a check valve structure 53 comprising a frame 54 which supports a spring 55. The spring 55 presses yieldably against a valve ball 59. rEhe valve ball 56 is held against a valve seat 5l which is mounted directly at the lower end of the perforated mandrel section 49 so that the valve 56 will act to obstruct the flow of fluid into the passageway 59 of the mandrel section 49. The perforated mandrel section 49 extends downwardly beyond the end of the intermediate housing section Bt. The lower end of the housing section is fitted with a tubular extension 59 of reduced diameter. VA counterbore 59 is formed in the tubular extension 58 to receive packing 69. A nut 6l is threaded into the outer end of the counteroore 59 to hold the packing. The extension 58 is externally threaded at 62 to engage threads 93 formed at the end of a coupling sub 64,. The mandrel 49 extends downwardly through the coupling sub 6d and therebeyond. A counterbore B5 is formed within this sub to receive a packing 6B. This packing is of relatively long length and serves not only to pack the mandrel so that it may have longitudinal movement and still remain fluid-tight but also to pack off the ports 5| when the mandrel section 49 is drawn upwardly to a position where the ports 5l will be closed. At the upper end of the extension sub 64 is an enlarged bore 6'! which provides a fluid passageway to establish communication between back circulation ports 68 and the ports 5l of the mandrel under certain circumstances. The back circulation ports 68 are formed through the Wall of the sub S4 and permit well fluid under hydrostatic pressure to flow into the tool as hereinafter described. The lower end of the connecting sub 64 is formed with a threaded extension 69 which is threaded into the upper end of a lower housing section 1B. The lower housing section 'I0 4terminates with a pin section 'H which may be threaded into the box portion of the upper end of a desired number of stands of pipe above the usual retaining valve structure.` rIhe lower housing section l0 is formed'with a relathreaded to receive a temporary plug i8.

tively large bore 'I2 which terminates in a smaller longitudinally aligned fluid passageway 'i3 extending through the pin section 'i l.

In the operation of the present tool, fluid under pressure may be entrapped between the bore 'i2 of the lower housing section 'i9 and the retaining valve under certain conditions and it will be necessary to relieve this pressure when the tool is withdrawn from the well in order to disassemble the structure. In order to accomplish this a releasing check valve is provided as generally indicated at ibi. This check valve comprises a housing portion i5 threaded into a bore 'E5 extending radially from the fluid passageway 23 and through the wall of the pin section 1l. The housing 'l5 is formed with a central bore The outer end of this bore is The inner end of the bore terminates in a valve seat 'i9 (Fig. 6) to receive a valve ball 89. The ball 9i! is yieldingly held on the seat by a spring 5l which is positioned by a retaining cap 92. The retaining cap 92 is threaded onto the inner end of the housing 'I5 and has a central fluid opening 83.

In order to bleed the entrapped fluid from the bore l2 in the lower housing section 'lll a tool B4 is provided as generally indicated in Fig. B of the drawings. This comprises a housing 55 formed with a threaded stem 86 at one end and a threaded counterbore 8l at its opposite end. The threaded stem 36 is designed to be screwed into the opening in the valve housing l normally receiving the temporary plug i8. A bore S3 extends through the housing from the counterbore Si and through the stem 89. At a point intermediate the ends of this bore a lateral threaded passageway 89 is provided to receive a threaded coupling 99. This coupling is carried by a bleed tube 9i. The threaded counterbore 8l of the housing 85 carries a tubular packing sleeve 92. This extends in longitudinal alignment with the bore 8S and receives an operating pin 93. rlhe cuter end of the pin 93 is threaded at 94 and fits into a threaded bore of the sleeve 92. The opposite end of the pin 93 has an extension portion 95 which passes into and through the bore 83 of the housing 85. The pin is made fluid tight by a packing 95. This packing is held in position by a packing nut 91.

In operation of the present invention the combined shut-:ln and back circulation tool is constructed as shown the drawings and is assembled with other instrumentalities as particularly shown in Fig. l of the drawings. As previously stated this is preferably used in connection with the formation or casing testing structures of the Patent No. 2,073,197 issued to Mordica O. Johnston on March 9, 1937, entitled Well Testing Method and Apparatus Therefor. In this structure a packer 99 is carried at the lower end o a tester 99 which includes a retaining valve 99. At the lower end of the packer there is a perforated anchor it! through which connate uid may iiow upwardly through the packer and the tester structure 99. 'When the packer 98 is set and the weight oi the drill string i9 is imposed upon the retaining valve ISB `of 'which it travels upwardly through the center acci-sos then through the central passageways 25' and?" 26 to the sub ld. In Viewv of' the tact that the trip valve li above the sub I4 is normally closed circulation through the tool I willi be interrupted by the trip valve Il. When the trip valve is opened by dropping a go-devil thereon or through some other instrumentality a sample of the connate fluid may pass upwardly through the tester Q9 and the tool I5. It is preferable to interpose a plurality of stands of pipe between the retaining valve lli and the combined shut-in and back circulation tool l5, so that an entrapped sample may be obtained when the shut-in tool is closed as will be hereinafter explained. lt is also to be understood that in common practice a pressure recording device is disposed within the perforated anchor so that the pressure of the connate fluid may be recorded. Normally the tool generally indicated at l5 isset as indicated in Figs. 2 and 3 of the drawings. At this time the ports si will be open below the connecting sub 54. In the event that it is desirable to entrapa shut-in sample weight is applied' to force the lugs gi2 downwardly out of engagement with keyways i3 and against the action of the spring 2s; The drill string and the mandrel section 241 may then be rotated so that the threaded section 40 of the mandrel will act to move the sleeve upward'- ly. The pitch of the threads 39- and lil are such as to require that the mandrel shall be rotated approximately seven times in order to draw the ports 5l into a closed position within the packing et. When the ports 5l have been closed the connate fluid which has risen through the open tester and the extra stands of pipe as indicated at le? in Fig. 1 of the drawings will be entrapped by the closing of the ports 5| and by the closing or the retaining valve lll@ in the tester QS as the string of pipe is lifted preparatory to being withdrawn from the well. It will be obvious that the entrapped fluid will be under the pressure of the connate fluid, which pressure will be recorded by the pressure recording mechanism placed within the perforated anchor. The entrapped sample of fluid cannot at this time pass upwardly through the drill string or outwardly through the valve structure '14, thus the shut-in pressure may be obtained.

In the event that it is desired to complete the test and withdraw the string of pipe and the testing tool from the well, pressure on the string of pipe is relieved on the testing tool so that the combined shut-in and back circulation tool and the tester t9 with its packer 98 may be withdrawn from the well. After the tool i5 has been withdrawn the recovered sample entrapped within the section of drill pipe |32 and the bore 'l2 at the lower end of the section 'it may be removed by use of the tool 84. This is accomplished by first unscrewing the plug 18 in the valve structure 'it and thereafter screwing the extension 86 of the tool 8d in the threaded bore from the threaded plug 18. When the extension 86 has been screwed into position the pin 95 may be advanced by its rotation and by the action of the threads 94 on the pin. This will force the pin S5 inwardly to encounter the valve ball 8D which will be moved from its seat against the expansive action of spring 8l. When this takes place the entrapped iiuid within the bore 'l2 and the length of pipe |02 will be expelled by the pressure which has been imposed upon the fluid. The entrapped iiuid which is the retained sample will then bleed out through the pipe 9| into a suitable receptacle.

En casecf emergency when: the packer 3.8i is. set it may be: desirable to impose a counter uid pressure upon the connate uid. in the well. This may be normally accomplished by creating a back circulation of fluid. downwardly through the string of pipe and theA tester. The back circulation ows downwardly throughy the tubular mand-rel t'ofmove the valve ball. ofi of' its seat 57:. In the event however that it is desiredto imposel the pressure of the hydrostatic fiuid head of the well upon the connate fluid the supporting string lil` is rotated in the same direction aspreviousl'y described for the rotation or" the threaded mandrel 2li' to draw the radial ports 5i of the perforated mand-rel 49 upwardly through the packing tt. Further rotation of thev threaded mandrel will draw the ports 5l upwardly into the bore 51 of the connecting sub dit. The duid within the well bore may then pass inwardly through the back circulation ports t8 and into the space 61. This fluid is under the pressure exerted. byY the hydrostatic head of fluid within the'well and this fluid will then be forced through the ports 5| and downwardly through the pas.- sageway 5e. to the ball valve 56. This valve is then opened so that the fluid under hydrostatic pressure may be imposed upon the connate fluid which. is attempting to rise from beneath the packer S8 and through the tester t9.

It willv thus be seen that the combined. shut-in and back. circulation tooll here shown is compact in. construction, and that it may be operated easily to insure that a shut-in pressure may be recorded, that a sample of the shut-in uid may be obtained, and that under emergency conditions it is possible to impose a superior' pressure upon that of the connate fluid' either by pump pressure through the drill string or hydrostatic pressure exerted by the column of fluid standing above the tool in. the well bore.

It is to be understood that the nut. 3l. and the intermediate housing section 35 are suitably splined together by splines 3l so that the nut may move longitudinally oi the housing section te as. the threaded section lil on the main tubular mandrel section. 2d is rotated.

While I have shown the preferred form of my invention as now known to me, it will, be under'- stood that various changes may be made in cornbination, construction and arrangement of parts by those skilled in the art, without departing from the spirit of the invention as claimed.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. An oil well tool for creating a shut-in pressure or back circulation within a string of pipe suspended in a well which comprises; an outer tubular housing adapted to carry an element formed with a well packer at its lower end and adapted to be connected to a supporting string of pipe at its upper end, said tool including: a tubular housing, a threaded tubular mandrel eX- tending upwardly therethrough and connecting with the supporting string of pipe, a traveling nut within the tubular housing and through which the threaded tubular mandrel section extends, a perforated mandrel section secured at the lower end of said nut and extending downwardly through the lower portion of said tubular housing, a check valve at the lower end of said perforate mandrel section to permit the outow of uid from said mandrel section, packing means within the lower portion of the housing and through which the perforate mandrel section extends, and ports through the side wall of the lower portion of the housing establishing communication between the interior thereof and the fluid within which the tool is submerged, the mandrel section being formed with radial ports which may be positioned by the rotation of the threaded mandrel section as the threaded nut is moved to dispose the ports in the mandrel section in an uncovered position below the packing and an uncovered position above the packing and a closed position within the packing and intermediate the ends thereof.

2. An oil well tool of the class described, comprising a tubular housing, a traveling nut slidably but non-rotatably received by the housing, a tubular mandrel telescopically received within the tubular housing and having means at its upper end for connection to a supporting string of pipe and having its lower end threadedly engaging said nut, a tubular section carried by the nut, extending downwardly therefrom, and having its lower end closed to the upward ilow of fluid thereinto, packing means within the housing below the nut and through which the tubular section extends, said housing having ports in the side wall thereof disposed above the packing means, said tubular section having ports formed in the side wall thereof initially disposed above the packing means in communication with the ports in the housing and adapted to be placed, upon rotation of the mandrel, within the connes of the packing means, or below the packing means in communication with the interior of the housing.

3. An oil well tool of the class described, comprising a tubular housing, a traveling nut slidably but non-rotatably received by the housing, a tubular mandrel telescopically received within the tubular housing and having means at its upper end for connection to a supporting string of pipe and having its lower end threadedly engaging said nut, a tubular section carried by the nut, extending downwardly therefrom, and having its lower end closed to the upward iiow of fluid thereinto, packing means within the housing below the nut and through which the tubular section extends, said housing having ports in the side wall thereof disposed above the packing means, said tubular section having ports formed in the side wall thereof initially disposed above the packing means in communication with the ports in the housing and adapted to be placed,

8` upon rotation of the mandrel, within the confines of the packing means, or below the packing means in communication with the interior of the housing, other packing means below the nut. disposed above the housing ports and through which the tubular section extends.

4. An oil well tool of the class described, comprising a tubular housing, a traveling nut slidably but non-rotatably received by the housing, a tubular mandrel telescopically received within the tubular housing and having means at its upper end for connection to a supporting string of pipe and having its lower end threadedly engaging said nut, a tubular section carried by the nut, extending downwardly therefrom, and having its lower end closed to the upward flow of fluid thereinto, packing means within the housing below the nut and through which the tubular section extends, said housing having ports in the side wall thereof disposed above the packing means, said tubular section having ports formed in the side wall thereof initially disposed above the packing means in communication with the ports in the housing and adapted to be placed, upon rotation of the mandrel, within the confines of the packing means, or below the packing means in communication with the interior of the housing, other packing means below the nut, disposed above the housing ports and through which the tubular section extends, spring means urging the tubular mandrel upwardly relative to the housing, and means preventing rotation of the tubular mandrel relative to the housing, responsive to downward movement of the mandrel relative to the housing to release the mandrel for rotary movement.

MORDICA O. JOHNSTON,

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,625,044 McKeonn Apr. 19, 1927 1,984,375 Johnston Dec. 18, 1934 2,073,107 Johnston Mar. 9, 1937 2,197,078 McKinley Apr. 15, 1940 2,229,636 Boynton Jan. 28, 1941 2,327,610 Savitz Aug. 2d, 1943 2,337,752 Johnston Dec. 28, 1943 2,404,825 Brown et al July 30, 1946

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