US3086387A - Retrievable casing tester - Google Patents

Description

April 23, 1963 G. E. LAYTON RETRIEVABLE CASING TESTER 2 Sheets-Sheet 1 Filed June 15, 1959 FlG 3 INVENTOR. GERALD E. LAYTON ATTORNEY Aprll 23, 1963 G. E. LAYTON 3,086,387

RETRIEVABLE CASING TESTER 7 Filed June 15, 1959 2 Sheets-Sheet 2 IN V EN TOR. GERALD E. LAYTON BY FIG. 2 ATTOR NEY 3,086,387 Patented Apr. 23, .1963

3,086,387 I RETRHEVABLE CASING 1 Gerald E. Layton, 3663 Monaco Parkway, Denver, Colo.

Filed June 15, 1959,Ser. No."820,'206 8 Claims. (Cl. 73-40;5)

This invention relates to equipment useful in the conditioning of deep earth bores, such as 01]. wells, and the like, for extension and production, and more particularly to an item of such equipment repetitiously applicable to facilitate test for imporosity ofi casing lengths as appropriate during placement of the casing forconventional operation within a bore, and has an object to provide a novel and improved unit selectively applicable to and retrievable from sealing coaction with the lower end interior of a casing length entered to ultimate use position at any depthwithin an earth bore.

A further object of the invention 1s to provide a novel and improved unit selectively applicable to and retrrevable from sealing coaction with the lower end interior of a casing length within an earth bore by means commonly available during and in reaction'to conditions conventionally attending placement of the casing.

A further object of the invention is to provide a novel and improved repetitiously-employable, retrievable unit selectively applicable to scaling coaction with the lower end interior of a casing length within an earth boreun reaction to fluid pressures regulably applied to the casing interior thereabove.

A further object of the invention is to provide a novel and improved repetitiously-employable unit selectively applicable to scaling coaction with the lower end interior of a casing length within an earth bore in react on to fluid pressures regulably applied to the casing interior and retrievable'upon abatement of such pressure through the sole agency a line conventionally complementary to casing placement operations.

A further object of the invention is to provide a novel and improved casing testing adjunct selectively applicable to and retrievablefrom sealing coaction with the lower torand retrievable from sealing coaction withthe lower end interior of a casing length within an earth bore that is compact in a light-weight unitary assembly amenable to controlled adjustment longitudinally of and operatively within earth bore casings in attachment to a line conventionally complementary to casing placement operations.

A further object of the invention to provide a novel and improved construction and operative correlation of elements constituting a testing adjunct selectively applicable to and retrievable from sealing coaction with the lower end interior of a casing length within an earth bore.

A'further object oi the invention is to provide a novel and improved retrievable casing tester that is simple and inexpensive of production from available materials in an extensive range of desired sizes, that is durable throughout a long life of repetitious use, that is effectively opertable in automatic reaction to influences regulably applied to and through the end of the casing accessible at ground level, and that is positive and efficient in attainment of the ends for which designed.

With the foregoing and other objects in view, my invention consists in the construction, arrangement, and operative combination of elements as hereinafter set forth,

pointed out in my claims, and illustrated by the accompanying drawing, in which FIGURE 1 is a vertical section longitudinally through the lower end portion of a casing length positioned for placement within an earth bore with a typicalembodi- 'ment of the invention shown in axial section as associated with the casing in its retrievable or potential-use condition, an intermediate length portion of the view not essential to an understanding of the invention being broken .away to conserve space.

FIGURE 2 is a vertical sectional view similar to FIG- URE 11 showing the fieatures and elements thereof in an alternative condition of operative interrelation.

FIGURE 3 is a section transversely through the organization according to the preceding views taken substantially on the indicated line 3-3 of FIGURE 1.

FIGURE 4 is a section transversely through the organization according to the preceding views taken sub stantially on the indicated line 4-4 of FIGURE 2.

Deep earth bores developed for the production of water, petroleum oils, gases, and the like, are commonly conditioned for production, and for extension in depth, through the provisionof bore linings in the form of continuous lengths of rigid, tubular, usually metallic casing assembled through the intercouplingot separate, like sections at the mouth of the bore as the completed length is lowered therethrough. As conditioned for casing, the bore confines, or may be charged with, a column of liquid whichis availed of .to, in an importantmeasure, counteract the progressively-increasing weight of the casing length descending therein, for which purpose the otherwise open, lower end of} the casing length is obstructed by a tubular plug, termed a float collar, coaxially and fixedly associated in anyva-ppropriate conventional manner with the end of the casing first inserted in the bore to restrict, but not to close, the path of liquid access to the casing interior, which plug, or float collar, is subsequently drilled out of thecasing upon completion of the desired casing placement. It being customary to finally-cement the placed casing. in its use position within the bore, and it being material to ultimate efficient production through the casing that the latter be free .from leak-age of confined flow therethrough, .it .is. approved practice to pr'es sure-test thecasing length for imporosity after placement and before cementinglthereofrelative to the bore, in expeditious, economical, (and practical .ifurtherance whereof the instant invention is directed to the provision of an adjunctive unit retrievably coacta'ble with the-float collar of a placed casing length to function as an abutment closing the lower end of the length in reaction to pressures applied interior-1y of-the casing thereabove flor test of casin g integrity.

Typifying the use environment of the invention, the lower end portion of a continuous length of conventional tubular casing is indicated "by the nuineral'lt) and shown in the views of the drawing .as looselyengaged at any appropriate depth within an earth bore for 'fixed emplacement relative thereto, and as furnished 'with a conventional, tubular, cementitious float collar 11, carried as is customary in a coupling 12 threadedly connectible with and as an-exten'sion of said casing length, partially obstructing its otherwise fully open lowerend to represent a flat, annular shoulder transversely of and opposed to the interior .of said length 10.

Selectively and retrievably operableto realization of its purposes within the environment typified by the casing portion 10, float collar 11, and coupling 12, the improvement-of the invention is a smoothly-cylindrical, axiallyelongated, unitary assembly of the elements hereinafter specified having a diameter substantially less than the interior diameter of the casing 10 adapting it for free reciprocation within the casing. 'lthe cylindrical, unitary assembly characterizing the invention 18 comprised from a generally-tubular lower end member 13 of rigid material, such as metal, a similar, generally-tubular upper end member 14 of rigid material coaxial with and spaced from said member 13, a thick-walled, tubular sleeve 15 of resilient material, such as rubber, or the equivalent, spanning between and permanently interconnecting said end members 13 and 14 in exteriorly-smooth, cylindrical conformity therewith, and stem components 16 and 1/ coaxially engaged with said end members, sleeve, and each other for relative axial displacement.

The assembly lower end member 13 is formed with a right-cylindrical, outer end portion traversed by an axial bore 18 substantially equivalent in flow capacity with the passage through the float collar 11 and hence presents a flat, perpendicularly-transverse end face adapted to conformably oppose the annular, upper shoulder of said float collar 11, to which flat end face of the member 13 is concentrically affixed a compressible annulus 19 engageable with sealing effect between opposed areas of said float collar and lower end member when the latter descends through the casing 10 to rest upon said collar. Inwardly of said member 113, the bore 18 1s divergently enlarged as a frusto-conical seat 20 from the great diameter base whereof said member extends as a concentric tubular skirt 21 having an inner diameter greater than that of the bore 18 and an outer diameter less than that of the outer end portion of said member, over which skirt one end of the sleeve 15 is telescoped and fixedly en- I gaged, as by one or another of the well-known techniques for securing rubber to metal, to conformably register the exterior of the sleeve with the greater-diameter base portion of the member 13 and to desirably register the tubular interior wall of said sleeve with the bore of enlarged diameter through said skirt. Identical with the end member 13 save for an alternative location of the frusto-conical seat associated with the bore therethrough, the upper end member 14 is formed with a right-cylindrical outer end portion traversed by an axial bore 22 whereof the outer end is divergently enlarged outwardly thereof as a frusto-conical seat 23, said bore 22 and seat 23 being desirably the functional equivalents of the bore 18 and its seat 20, and with a tubular skirt 24 conformable With the skirt 21 concentrically extending therefrom in shouldered relation about the inner end of the bore 22 to telescopic engagement within and fixed attachment to the end of the sleeve 15 opposed thereto.

In a straight, rigid, cylindrical conformation of a diameter considerably less than that of the bore 22, the stem 16 is loosely accommodated in and for axial reciprocation relative to said bore in a length such as to extend at one end well -within the sleeve 15 in simultaneous projection of its other end outwardly beyond the end member 14 housing said bore, and lugs 25 fixedly project radially and outwardly from said stem 16 interiorly of the skirt 24 as a stop diametrically of said stem in an effective length greater than the diameter of the bore 22 adapting them to engage at times with the shoulder at the junction of the skirt 24 with its member 14 for consequent limitation of stem 16 travel outwardly of said member. The end of the stem 16 exterior to the member 14 is formed with an eye 26, or the equivalent, connectible with an end of a line 27 whereby the unit of the invention may be translated within the casing 10 when the lugs 25 are in engagement with the shoulder about the inner end of the bore 22 as a consequence of stem 16 travel to the outer-most limit of its shiftable range relative to the member 14. Exteriorly adjacent the member 14 in an appropriate spacing from the lugs 25, a frusto-conical valve plug 28 is coaxially fixed to the stem 16 in a conformation appropriate for sealing coaction with the seat 23' outwardly terminating the bore 22, the spacing of said plug 28 axially of the stem 16 away from the lugs 25 being such as to fully separate said plug from the member 14 and its seat 23 therein when the lugs 25 are in engagement with the annular shoulder at the inner end of the bore 22, substantially as represented by FIGURE 1, and to engage said plug within its seat 23 when said lugs are adjacent the end of the skirt 24 remote from the member 14 at the limit of stem 16 travel inwardly through the bore 22, as represented by FIGURE 2. Telescopically coactable with the inner end of the stem 16 within the sleeve 15, the stem 17 is tubular in a maximum diameter less than that of the skirt 21 interior and is closed at its end receivable in said skirt by a frusto-conical plug 29 adapted to coactively engage at times with the seat 20 inwardly terminating the bore 18 of the member 13; the tubular portion of the stem 17 being of a length to maintain telescopic association with the inner end of the stem 16 in all operating positions of the latter and in all correlations of said stem 17 with its seat 20.

A casing length 10 furnished with a float collar 11 having been lowered within an earth bore and positioned therein ready for cementing in place, testing of such length for leakage is very much facilitated and expedited through use of the improvement hereinabove described. A unitary assembly exemplifying the invention being available in a diametric size freely and loosely reciprocable within the casing length to be tested, the same is lowered in attachment to a line 27 as set forth through the casing length to engagement of its lower end against the annular shoulder presented by the upper face of the float collar wherewith the annulus 19 coacts to seal about the passage through the collar, the weight of the assembly, the separation of the valve plug 28 from its seat 23 incident to the lowering operation, and the absence of any restraint inhibiting lifting of the valve plug 29 from its seat 20 combining in an obvious manner to promote descent of the assembly through the liquid column present in the casing and to charge the assembly interior with the liquid of such column. With the annulus 19 at the lower end of the assembly resting upon the upper face of the float collar 11 as tension on the line 27 is relaxed to free the assembly from such influence, the upper end of the casing length is suitably closed by means accommodating input of fluid under pressure to the interior of the length and a pressure charge is developed within the casing with constant reference to gauge readings responsive thereto. Pressure developed within the closed casing length above the assembly resting upon the float collar immediately acts to intensify the sealing action of the annulus 19 about the passage through the collar and to securely close the valve plug 29 in and to its seat 20 and thereby prevent escape of the applied pressure from the lower end of the casing length, to initially invade the interior of the sleeve 15 through the unplugged seat 23 and bore 22 of the upper end member 14, and to progressively contract the axial length of the sleeve and end member assembly with radial distention of the sleeve into tight sealing coaction with the casing interior pursuant to closing coaction of the valve plug 28 with its seat 23, as in FIGURE 2. Closed at its lower end with a seal deriving from and proportioned in effectiveness to the fluid pressure applied thereto, the interior of the casing reflects the input pressure of the fluid when secure against leakage and will register any imperfections by a drop of pressure below the fluid input value, as is conventionally recognized. Upon completion of the test, the applied pressure is relieved, the upper end of the casing length opened, and the line 27 retracted from the casing to first lift the valve plug 28 from its seat 23 and open an outlet from the sleeve 15 as the latter contracts to normal diameter away from engagement with the casing, whereafter continued retraction of the line 27 lifts the stem 16 to engagement of its lugs 25 with the shoulder at the inner end of the bore 22 and thereby retrieves the assembly from the casing in condition for check of its operative perfection and for reuse described may be had without departing from the spirit of my invention, '1 wish to be understood as being limited solely by the scope of the appended claims, rather than by any details of the illustrative showing and foregoing description.

I claim as my invention:

1. A tester unit for retrievable coaction with a length of tubular well casing downwardly terminated by a conventional float collar, comprising a cylindrical assembly loosely receivable within the casing for free reciprocation longitudinally thereof, means at one end of said assembly connectible with a line manipulable to regulate assembly travel relative to the casing, means at the other end of the assembly adapted for sealing coaction with the float collar at the limit of assembly travel downwardly through the casing, an elongated, tubular, resilient component intermediately intercoupling the opposite end portions of said assembly in flow communication therethrough, slidably-interrelated means coaxial with said component reciprocable axially of the assembly to accommodate fluid flow upwardly therethrough in automatic reaction to lowering of the line-suspended assembly within the casing and-concurrently to inhibit fluid flow downwardly through the assembly, and elements in said latter eans automatically reactive to supported engagement of the assembly with the float collar and consequent relief of tension on the line to interrupt communication between the interiors of said component and the casing, whereby to apply fluid pressures introduced to the casing above the collar-seated assembly for length-contraction of said component and concomitant radial expansion thereof into sealing compression against the surrounding casing.

2. A tester unit for retrievable coaction with a length of tubular well casing downwardly terminated by a conventional float collar, comprising a cylindrical assembly loosely receivable within the casing for free reciprocation longitudinally thereof, means at one end of said assembly connectible with a line manipulable to regulate assembly travel relative to the casing, means at the other end of the assembly adapted for sealing coaction with the float collar at the limit of assembly travel downwardly through the casing, an elongated, tubular, resilient component in said assembly, a flow passage serving the interior of said component through the opposite ends of the assembly, a check valve automatically accommodative of upward flow and inhibitive of downward flow at the lower end of said passage, and a complementary check valve at the upper end of said passage reactive to tension of the manipulating line to open the passage end thereby controlled when the line is under tension and to close said passage end when line tension is relieved through seated engagement of the assembly with the float collar, whereby to apply fluid pressures introduced to the casing above the collar-seated assembly for length-contraction of said component and concomitant radial expansion thereof into sealing compression against the surrounding casing.

3. A tester unit for retrievable coaction with a length of tubular well casing downwardly terminated by a conventional float collar, comprising a cylindrical assembly loosely receivable within the casing for free reciprocation longitudinally thereof, an elongated, tubular, resilient component constituting the major length of said assembly, a flow passage serving the interior of said component through the opposite ends of the assembly, means circumscribing said passage at one end of said assembly adapted for sealing coaction with the float collar-at the limit of assembly travel downwardly through the casing, a stern loosely through and reciprocable axially of the passage at theother end of the assembly, means at the end of said stem exterior to the assembly connectible with a line manipula'ble to regulate assembly travel relative to the casing, lugs fixedly projecting radially from said stem interiorly of the assembly adapted to limit relative .displacement of said stem outwardly of the assembly, an outwardly-divergent valve seat terminating the passage traversed by said stem, a valve plug coactable with said ;seat -;fixe d';to said stem in a'spacing from said lugs such ;as to separate .theplug from its seat when said stem .is "at thel mit of its displacement outwardlyrof the assembly,

stem interiorly ,ofthe assembly, a valve plug terminating a tubular stem-telescopically associated with said first said tubular stem at the end thereof remote from said first stem, and 'a valve seat coactable with the plug car- ;ried by said tubular stem terminating the flow passage :theretoopposed interiorly of the assembly, whereby to conditionsaid assembly for the accommodation of fluid flow upwardly therethrough when suspended in tension- :ing relation with the manipulating line :and for inhibition ;of fluid flow downwardly relative to either end thereof when seated upon the'float collar with consequent relief of line tension.

'4. ,A tester unit for retrievable coaction with a length of :tubular well casing downwardly terminated by a conventional float collar, comprising an elongated, tubular, resilient sleeve :loosely receivable within the casing for the opposite ends of said sleeve in exterior conformity therewith, flow passages axially through said members in an filTfiCllVEySlZflrTfitdllCd relative to the sleeve interior, an outwardly-divergent valve seat exteriorly terminating one of said passages, a stem loosely through and reciprocable axially of said latter passage, a valve plug fixed to said stem exteriorly of and for coaction at times with said seat, lugs fixedly projecting radially from said stem interiorly of said sleeve adapted to limit relative displacement of said stem outwardly of the member thereby traversed in a spacing from said plug such as to separate the latter from its seat when said stem is at the outward limit of its travel range, means at the exterior end of said stem connectible with a line manipulable to regulate travel of the sleeve and member assembly relative to the casing, whereby to oppose the member remote from said stem to and for seated coaction with the float collar, a check valve accommodative of fluid flow upwardly and inhibitive of flow downwardly through the passage of the member remote from said stem, and a resilient sealing ring circumscribing the passage opening through the exposed end of said latter member.

5. A tester unit for retrievable coaction with a length of tubular well casing downwardly terminated by a conventional float collar, comprising an elongated, tubular, resilient sleeve loosely receivable within the casing for free reciprocation longitudinally thereof, like, cylindrical members of rigid material fixed to and coaxially closing the opposite ends of said sleeve in exterior conformity therewith, flow passages axially through said members in an effective size reduced relative to the sleeve interior, an outwardly-divergent valve seat exteriorly terminating one of said passages, a stem loosely through and reciprocable axially of said latter passage, a valve plug fixed to said stem exteriorly of and for coaction at times with said seat, lugs fixedly projecting radially from said stem interiorly of said sleeve adapted to limit relative displacement of said stem outwardly of the member thereby traversed in a spacing from said plug such as to separate the latter from its seat when said stem is at the outward limit of its travel range, means at the exterior :end of said stem connectible with a line manipulable to regulate travel spams? of the sleeve and member assembly relative to the casing, whereby to oppose the member remote from said stem to and for seated coaction with the float collar, a valve seat divergent toward the interior of said sleeve inwardly terminating the passage through said latter member, a tubular stem telescopically associated for reciprocation with and as a coaxial extension of said first stem interiorly of said sleeve, and a valve plug terminating said tubular stem at the end thereof remote from said first stem for coaction at times with the valve seat opposed thereto.

6. In a tester unit for retrievable coaction with a length of tubular well casing downwardly terminated by a conventional float collar constituted as a cylindrical assembly loosely receivable within the casing for free reciprocation longitudinally thereof, means conditioning said assembly to function as a stopper obstructing the casing adjacent the float collar in automatic reaction to fluid pressures introduced to the casing thereabove, said means comprising an elongated, tubular, resilient sleeve constituting the major length of said assembly between like, rigid members fixed to the ends thereof, flow passages through said end members in an eflective size reduced relative to the sleeve interior, a resilient ring circumscribing the passage opening through the exposed end of one of said members adapted for sealing coaction with the float collar at the limit of assembly travel downwardly through the casing, a check valve accommodative of flow upwardlyand inhibitive of flow downwardly through the passage circumscribed by said ring, a check valve accommodative of fluid flow upwardly from and inhibitive of flow downwardly through the passage of the other end member, and means, including a line manipulable to regulate assembly travel relative to the casing, associated with said latter valve to permit closing thereof only when tension on the manipulating line is relieved.

7. The organization according to claim 6, wherein the check valve controlling flow through the passage of the end member remote from the sealing ring includes an outwardly divergent valve seat at the exterior end of the passage, a stem loosely through and reciprocable axially of the passage so modified, means on said stem interiorly of the assembly adapted to limit relative displacement of the stem outwardly of the assembly, means connectible with the manipulating line at the exterior end of said stem, and a valve plug coactable at times with said seat fixed to said stem exteriorly of the assembly in a spacing outwardly away from said seat when said stem is at the limit of its displacement outwardly of the assembly.

8. The organization according to claim 6, wherein the check valve controlling flow through the passage remote from that circumscribed by the sealing ring includes a stem reciprocable axially of the assembly and extending therewithin, and the check valve controlling flow through the passage circumscribed by the sealing ring is organized as a valve seat divergent toward the interior of said sleeve at the inward end of the passage opening through the sealing ring, a tubular stem telescopically associated for reciprocation with the terminal portion of said first stem within the assembly, and a valve plug at the end of said tubular sleeve remote from said first sleeve coactable with the valve seat opposed thereto.

References Cited in the file of this patent UNITED STATES PATENTS 1,652,472 Erwin Dec. 13, 1927 1,822,925 Granger Sept. 15, 1931 1,955,113 Davenport Apr. 17, 1934 2,128,716 Smith Aug. 30, 1938 2,545,102 Miller Mar. 13, 1951 2,715,444 Fewel -5 Aug. 16, 1955 2,767,795 Bush Oct. 23, 1956 2,841,007 Loomis July 1, 1958 2,963,092 Anderson et al Dec. 6, 1960

Claims (1)

1. A TESTER UNIT FOR RETRIEVABLE COACTION WITH A LENGTH OF TUBULAR WELL CASING DOWNWARDLY TERMINATED BY A CONVENTIONAL FLOAT COLLAR, COMPRISING A CYLINDRICAL ASSEMBLY LOOSELY RECEIVABLE WITHIN THE CASING FOR FREE RECIPROCATION LONGITUDINALLY THEREOF, MEANS AT ONE END OF SAID ASSEMBLY CONNECTIBLE WITH A LINE MANIPULABLE TO REGULATE ASSEMBLY TRAVEL RELATIVE TO THE CASING, MEANS AT THE OTHER END OF THE ASSEMBLY ADAPTED FOR SEALING COACTION WITH THE FLOAT COLLAR AT THE LIMIT OF ASSEMBLY TRAVEL DOWNWARDLY THROUGH THE CASING, AN ELONGATED, TUBULAR, RESILIENT COMPONENT INTERMEDIATELY INTERCOUPLING THE OPPOSITE END PORTIONS OF SAID ASSEMBLY IN FLOW COMMUNICATION THERETHROUGH, SLIDABLY-INTERRELATED MEANS COAXIAL WITH SAID COMPONENT RECIPROCABLE AXIALLY OF THE ASSEMBLY TO ACCOMMODATE FLUID FLOW UPWARDLY THERETHROUGH IN AUTOMATIC REACTION TO LOWERING OF THE LINE-SUSPENDED ASSEMBLY WITHIN

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