US2929452A - Well pipe wash-over and clean-out tool - Google Patents

Description

March 22, 1960 F. I. ALEXANDER WELL PIPE WASH -OVER AND CLEAN-OUT TOOL Filed Feb. 24, 1958 INVENTQR.

2,929,452 WELL PIPE WASH-OVER AND CLEAN-OUT TOOL Ford I. Alexander, Arcadia, Calif.

Application February 24, 1958, Serial No. 717,122 Claims. or. 166-103) This invention has to do with improvements in oil well fishing tools of the wash-over type, constructed and operated primarily to remove sand or other formation more or less compacted about the fish, consisting of a bottom length of one or more drill pipe stands which have become stuck in the wall by reason of the sand compaction about them.

When the drill string has become stuck in the well, a general practice has been to determine the so-called stuck point, unscrew the pipe string just above that location, and to then lower about the upper exposed end of the stuck pipe a wash-over tool consisting essentially of a long piece of pipe somewhat larger in diameter than the stuck string, and having a bottom lower cutting edge capable upon rotation of removing the formations surrounding the stuck pipe, aided by fluid circulation through the wash-over pipe.

It frequently happens that the stuck pipe may beinternally plugged by sand or the like that has entered the pipe following disconnection of its upper free extent. The plugged condition of the stuck pipe interferes with the desirable maintenance or attempted maintenance of fluid circulation through the pipe as an aid in removing it. Where this plugged condition has existed, and it is desired to attempt restoration of circulation through the pipe, a customary practice has been to run down in the Well an appropriate clean-out tool after completion of the wash-over operation.

My primary object now is to provide a combination wash-over and fish-clean-out tool whereby in one operation compacted or plugging sand may be removed and circulated to the ground surface from both outside and inside the fish. In achieving this object I provide within what essentially may be the conventional wash-over type, a drill rod positioned to enter the fish, carrying at its lower end an appropriate tool capable of loosening, drilling, or reaming out the sand plug inside the fish.

Structurally, the invention contemplates positioning within and in axial alignment with the wash-over pipe, a small diameter drill rod, the length of which may more or less approach that of the wash-over pipe, while being of sufiicient extent to be capable of running through one or more stands of stuck pipe and any clogging accumulations therein. The internal drill rod preferably is tubular in order to conduct circulation down into the fish as the clean-out progresses, all to the end that circulation may occur simultaneously both inside and outside the fish.

According to a typical though preferred embodiment of the invention, the drill rod is so accommodated within the wash-over pipe as to be capable of relative axial movement while being rotatably associated with the outer pipe. As will appear, this relation may be accomplished by supporting and centering the drill rod by radially extending members which travel along one or more longitudinal shoulders on the wash-over pipe which restrain or prevent relative rotation but allow relative axial movement of the two pipes.

A further object of the invention is to provide an inateht the pipe string, may be given the drill rod by supporting ternal drill rod of the character described, which may be retrieved through the pipe string suspending the washover pipe, if for any reason advance removal of the drill rod is desired. The capacity for operative association with the wash-over pipe and also removability through or guiding it within the wash-over pipe by an arrange ment of radial springs which may be collapsed into and removed with the rod through the pipe string.

The various features and objects of the invention, as

well as the details of an illustrative embodiment, will be fully understood from the following detailed descrip-.-

tion of the accompanying drawing, in which: 1 Fig. 1 is a general view, partly in vertical'section, showing the wash-over and clean-out tool being run 'into a well containing the fish;

Fig. 2 is an enlarged sectional view showing the toolapplied to the fish;

Fig. 3 is a cross-section on line 33 of Fig. 2, and

Fig. 4 is a view illustrating a variational feature of the invention.

Referring first to Fig. 1', the tool generally indicated, at 10 is shown to be lowered into the well on the com ventional pipe string 11 running-through the rotary table.

12 and suspended by the usual elevator 13. The fish 14, usually an open hole below the casing 15 is shown as .the upper end of stuck drill pipe embedded in the loose formation or sand 16. As illustrated in Fig. 2, the tool 10 comprises an extended length of easing or other pipe 17 larger in diameter than the fish 14, to the extent in-, dicated at 18, so that while fluid circulation. may occur from within the pipe into the well through the clearance at'18, thelatter is :sufliciently restricted to maintain a back pressure tending to circulate also into the fish. At its lower end, the pipe 17 may carry an appropriate cutting edge or tool 19 action upon rotation of the pipe to loosen the sand 16 for entrainment in the fluid circulation returning to the ground surface. At its upper end the pipe 17 is shown to be connected to a shorter length sub 20 in the wall of which are two or more longi- I tudinal recesses 21 presenting shoulders 22 functioning in relation to the rod centering springs as will presently appear. The sub 20 is connected by coupling 23 to the lower end of the drill string 11.

Centered within the pipe 17 is a tubular small diameter drill rod 24 which, if desired, may approach in length the total length of the wash-over tool. The rod 24, together with a suitable bit or sand loosening tool 25 at its lower end, is sufiiciently small to enter the bore of the fish with some clearance to allow return fluid circulation upwardly about the rod after it has entered the fish. The rod is shown to be supported by a pair of arms 26 rigidly aflixed at 27 to the rod and terminating within the grooves 21. Rotation of the wash-over pipe is transmitted to the rod through rigid or resiliently flexible arms 26 hearing against the shoulders 22, while axial movement of the 'rod within the outer pipe is permitted by the movability of the springs longitudinally within the grooves 21. Near its lower end the rod 20 may be given centered support by spring arms 28 carried by sleeve 29 through which the rod is slidable. Downward movement ofthe rod within the wash-over pipe is positively limited, as shown in Fig. 2, by the engagement of arms 26 at 29 with the upper end of the pipe 17 threaded into the bottom of the sub 20.

As previously indicated, the rod 24 may be rendered removable from the wash-over pipe through the string 11. For this purpose, arms 26 and 28 both may be made sufficiently thin and flexible to collapse in the bore of the suspending string. Thus an appropriate tool or grapple may be lowered on a wire line through the string 11 to connect with the rod terminal 30, and the rod assembly pulled up into and through the pipe string Patented Mar. 22, 1960';

3 firstbyradialeollapsing 'oftlre springs 26 and subsequently thesprings '28 by virtue of the engageabilityof the bit 25 with sleeve 29.

.In operation, the tool is lowered to the Fig. 2 position about the fish, and rotation commenced with fluid circulation from" the string -11. The edge or tool 19 cuts ;away'the outside "sand -1'6,freeing'it for entrainment in the circulating fluid discharging through the clearance 18. Simultaneously, and progressively as the outside .sandremoval continues, bit 25 entersthe pipe 14-and loosensor cuts up :the plugging sand which becomes entrained and removed from the-pipe bore in the circulating fluid stream flowing into the open top end of the drill rod and downwardly through thebit. As will be apparent, the drill rod needonly :be-small in diameter and a relatively lightweight, since it can 'be given ample length for imposing 'on-the bit 25,-suflicient weight to cut out the sand-plug. Although vertically flexible, particul-arly "if designed for withdrawal through the 'string 11, the springs 26 have sufiicient resistance to twisting 'deflectionastotransmit-to the'rods 24that degree of torque necessary for the loosening of sand plugging the fish.

It may be desirable -to restrict the fluid passing rspace betweenmod '24 and therbody .17 below the;.top fluid entry end of the rod, and thus creating pressure difierential conducive to an :iucrease proportion of thecirculation throughithe rod. Such restriction may be effected in any of various :ways,:typically .by: the insertion below the .sub 20 of 1a :restrictor ring 33, .the .bore of whichhas 'clearance about the rod .24 aample ..for ;the

wash-over flown-while tappreciably :restricting the how .so :as :tocreate .a :tendency "for .:increased circulation through the :rodtinto "the .fish. Where ithe tool is designed .for

removal ofthe trod .24, the :bore :of ring 33 will ;passthe lower guide aspring "arms 128.

'flrclaim:

1. .A tool dorathe aremoval ;of :sand :and other formation from both about and within :a-sstuck'well pipe fish,

:said .tool comprising an outer pipe body adapted to be lowered in a .pipe string and of larger diameter than the fish sothat the body is rotatable to penetrate and remove-sand from about the fish while conducting fluid circulation thereto @from the pipestring, arodpositioned axially :within said body for rotationtherewith and having :a lower tool end operable to enter :and progressively remove .san'd'plugging the fish as the body is rotated,

and means interconnecting the rod and body for rotation and downward movement together.

2. A tool as defined by claim 1, in which said rod is tubular and conducts circulating fluid into the fish.

3. A tool as defined by claim 1, in which said interconnecting means is movable relative to the body and releasable to disconnect the body and rod and the rod is removable from the body upwardly through the pipe string.

4. A tool as defined by claim 1, in which said means is movable vertically within the body so that the rod is vertically movable in and relative to the body during its sand removing operation.

5. A tool as defined by claim 2, in which said interconnecting means includes interengaging guide means on the rod and body for transmitting rotational movement from the body to the rod while allowing said vertical movement of the rod.

6. A tool as defined by claim 1, including means'in addition to'said interconnectingmeans for centering the rod within the body.

7. A tool as defined by claim 6, in which said centering means is a spring device carried by the rod.

8. A tool as defined by claim 1, in which said rod is movable vertically in the body, the tool also comprising stop means positively limiting the rod against downward movement out of the body.

9. A tool as-defined by claim 1, in which'said interconnecting rneans includes radially extending flexible resilient spring means carried by the rod and engaging the body, said' rod and flexible means being removable upwardly through the pipe string.

1'0. A tool 'as defined by claim 9, inwhich the rod is tubular and said flexible means travels along and within a longitudinal recess in the wall of the bodysothat rotation of'said flexible means relative to the 'bodyis restrained.

References Cited in the file of this patent

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