US2427052A - Oil well tool - Google Patents

Description

J. GRANT 2,427,052

OIL WELL TOOL Filed June 17,4 1944 t INVENTR.

@lbf/lv @Wirf Patented Sept. 9, 1947 on. WELL Tool.

John Grant, Los An Grant Oil Tool Company,

geles, Calif.,` assignor vto Los Angeles, Calif.,

a corporation of California Application June 17, 1944, Serial No. 540,804

13 Claims.

This invention has to do with oil well tools of the expansible cutter type, adaptable for various purposes in removing material from the well bore or casing, and particularly for scraping cement from the inside of the casing.

Like other so-called wall or casing scrapers, the present tool comprises a body carrying a plurality of cutters movable radially within openings or slots in the body. In distinction to prior tools of this character, the invention embodies various improvements having to do primarily with the cutter actuating mechanism and associated means for maintaining fluid circulation through the tool.

One of my major objects is to provide a mechanically simple and positively acting means for radially moving or positioning the cutters, whether to expand them from initially contracted positions, or normally to maintain them in expanded condition subject to radial contraction under conditions as later explained. Briefly, this object is accomplished by providing wedge means engaging the cutters, preferably at angular end surfaces thereof, and movable relatively to effect expansion and permit contraction of the cutters. As will appear, the invention broadly contemplates maintenance of the cutters in expanded condition either by uid pressure or by virtue of spring means urging the wedge means in a cutter expanding direction, and it is further contemplated that an individual tool may be adapted, by adjustment of its parts, to operate in either manner. l

A further object, directed primarily to fluid pressure operation of the cutter, is to adapt the wedge elements, as by making them in the form of plungers or pistons, for operation by the circulating iluid pressure While maintaining the fluid flow through the body, as to a pilot tool at its end. Accordingly, in one preferred form of the invention the Wedge elements have the form of tubular plungers or pistons with a fluid passageI connection permitting relative axial movement of the plungers while maintaining closed circulation through the body and plungers. Normally the cutters may remain contracted by a springjresisting cutter expanding movement of the wedge elements. Upon the application or development against the wedge elements of fluid pressure sufficient to overcome the resistance of the spring, the cutters are expanded and so remain until reduction of the fluid pressure permits their contraction. t I

- Of particular importance with respect to the use of the tool for scraping cement from casing Ill f is served by using wedge surface angularities normally capable of maintaining the vcutters in expanded condition, and yet permitting Ainward cutter movement and corresponding displacement of the Wedge elements under the conditions stated. All the various features and objects of the invention; as well as the details of a typical and preferred embodiment, Will be more clearly understood from the following description throughout which reference vis had to the accompanying drawings. in which:

Fig. 1 is a sectional View of the tool showing the cutters in contracted position; "Fig, 2 is a similar view illustrating a variational adaptation of the invention, with the cutters appearing in expanded position;

Fig. 3 is a cross-section on line 3 3 of Fig. l; and

Fig. 4 is a cross-section on line 4-4 of Fig. 2.

As a typical use, the tool may be run down in an oil well casing for the purpose of removing cement or other hardened cake from theV wall of the casing, designated by the dash lines I0. As illustrated, the tool comprises a tubular body Il having a threaded box end I2 receiving the pin I3 of -a tubular sub I4 connected to the drill pipe l5. The body II -contains a straight cylindrical bore I 6 communicating at its lower end through reduced diameter bore I1 with one or more passages I8 through which circulating fluid is discharged at the outside of a pilot tool which may be of any suitable type and character, as for example a bit I9 formed integrally with or other- Wise Yattached to the body.

The body contains a plurality of longitudinally extending, radial-slots '20, three being shown as typical, each containing a cutter 2| in the form of a blade having a cutting edge 22 facing in the direction of cutting rotation of the tool, and an inneriiange vedgeV presenting shoulders- 23 engageable against the bodyto limit outward radial movement of the cutter. In both illustratedV forms of the invention,- the cutters co-act with a pair-of wedge elements, generally indicated at 24 and 25 movable relatively together and apart, and engaged against angular Wedge surfaces 26 and 2'I on the inner end portions of the cutters. Preferably, the wedge elements 24 and 25 are made-inthe form of tubular plungers or pistons 284 and 2 9 movable axially within body bore I6 and having substantially uid-tight engagement therewith. To this end, the plungers may carry a suitable number and arrangement of sealing rings 30. Provision is made for maintaining closed flow or circulation of fluid from the sub I4 through the body II and Wedge elements, by means of a wash pipe 3I carried by and movable with one of the plungers, for example the upper plunger 28, and extending within and movable relative to the other plunger '29. Thus the wash pipe may be welded at 32 Within the bore 33 of plunger 28, and permitted movement Within the bore 34 of plunger 29, seal rings 35 being used to prevent fluid leakage around the wash pipe.

In the form of the invention shown in Fig. 1, the plungers 2B and 29 normally are urged apart to limiting positions of engagement respectively with the end shoulder 36 of pin I3 and the internal body shoulder 31, by a coil spring 38 placed about the wash pipe and bearing against the plunger. The full end areas of the plungers, are exposed to the fluid pressure by providing the plungers with lugs 28I and 291 engageable against the surfaces 36 and 3l. The cutters 2I thus are permitted to assume their contracted or inner-most radial positions, in which they remain during lowering and withdrawal of the tool preceding andv following its operation to remove material from the casing Wall.

In considering the operation of the tool, assume the latter to be lowered to working location with the parts in the position of Fig. 1. It will be observed that closed fluid circulation is permitted through the tool to the passage or passages I8 by way ofthe wash pipe 3I. By increasing the fluid pressure to a degree causing the pressure applied to the plungers 28 and 29 to overcome the resistance of spring 38, plungers are moved relatively together, causing their Wedge surfaces -39Vto expand the cutters 2I. Upon clockwise rotation of the tool, the cutters engage and shear off cement or other removable accumulations on the wall of the casing. While thus expanded, the cutters are supported by the wedging engagement of the plungers, until such time Vas the fluid pressure is relieved to permit spring 38 to return the plungers to their normal position, and remove resistance to inward movement of the cutters` However, the cutters are not rigidly supported in their expanded positions against inward movement, since it is important that they be inwardly movable as their cutting edges encounter irregularities. Thus the angularityof the wedge surfaces 26 and 39 is selected (e. g. at about 20 to 45 degrees) to permit temporary inward movement of the cutter as it passes an irregularity in the casing, and then restore the cutter to its outer or expanded position. It will be appreciated that the primary consideration affecting the radial support given the cutters is the fluid pressure applied to the plungers, and that this pressure is controllable, as desired., at the ground surface. Ordinarily, in actual operations, the expansion of the cutters will be limited by their engagement with the casing and short of the maximum expansion represented in Fig. 4.

Referring tothe variational form of the inventionshown in Fig. 2, it isr contemplated that, utilizing the same plunger and wash pipe arrangement, the cuttersnormally may be maintained in expanded positions and permitted inward displacement as the cutters encounter irregularities or constrictions in the casing during their vertical movement therein. In order tadapt a single tool for use and operation in either form, the spring 38 in Fig. 1 may be made in two sections 38a and 38o. After disassembling the tool and removing the spring sections, the l parts may be reassembled in condition of Fig. 2. in which the spring sections 38a and 38D are inserted respectively within the bores 40 and 4I of the plungers and to bear, under compression against the pin end 36 and the body at 42. to urge the plungers together and thereby expand the cutters. The inner engaging wedge surfaces 43 and 44 may be given angularities such that as the cutters encounter irregularities or obstructions during moving of the tool into and out of the casing, and during operations, the plungers may be displaced sufficiently apart by the cutter pressure, to permit inward movement of the cutters to an extent permitting them to pass such obstructions or irregularities.

I claim:

1. A Well tool of the character described comprising a tubular body, a radially expansible cutter carried in an opening in the body, a pair of spaced wedge elements both having wedge surfaces engaging end portions of the cutter and both movable in opposite directions within the body bore to effect radial movement of the cutter by virtue of such movement of the elements in opposite directions, and a tube extending between and movable relative to one of said elements, said tube being carried by one of said elements and movable within the other element and forming a, closed passage to conduct circulating fluid through the space between said elements.

2. A well tool of the character described comprising a tubular body, a radially expansible cutter carried in an opening in the body, a pair of spaced wedge elements both having wedge surfaces engaging end portions of the cutter and both movable in opposite directions within the body bore to eiect radial movement of the cutter by virtue of such movement of the elements in opposite directions, a tube extending between and movable relative to one of said elements, said tube being carried by one of said elements and movable within the other element and forming a closed passage to conduct circulating fluid throughv the space between said elements, and springs urging said elements toward each other to expand the cutter.

3. A well tool of the character described comprising a tubular body, a radially movable cutter carried by the body, a pair of plungers both reciprocally movable within the body bore in opposite directions and both having wedge surfaces engageable against said cutter to effect radial movement thereof by virtue of such movement of the plungers in opposite directions, means sealing off fluid leakage between said plungers and the body bore, and means forming a closed circulating fluid passage within said bore through and between the plungers.

4. A well tool of the character described comprising a tubular body, an elongated cutter blade extending radially through a longitudinally extending opening in the body, a pair of Wedge elements both reciprocally movable within the body bore in opposite directions and each having wedge engagement against a wedge surface on an opposite end portion of said blade to effect radial movement thereof by virtue of such movement of the elements in opposite directions, and means for simultaneously actuating both said wedge elements to expand said end portions of the blade substantially the same radial distance.

5. A Well casing scraper comprising a tubular body, a cutter blade having an outer cutting edge and carried by the body for radial movement, a pair of wedge elements both reciprocally movable within the body bore in opposite directions and each having wedge engagement against the cutter, said wedge elements operating during and by virtue of their movement in opposite directions to move the cutter radially While its cutting edge remains in substantially constant angular relation to the axis of the body, and means maintaining the cutter against substantial movement longitudinally of the body.

6. A well tool of the character described for cutting material from the Wall of a bore, comprising a tubular body, a radially expansible cutter carried by the body, a, pair of Wedge elements engaging the cutter, both of said elements being movable in opposite directions within the body and each having wedging engagement with opposite end portions of the cutter to effect radial movement of the cutter by virtue of such movement of the elements in opposite directions, and means for actuating said wedge elements- 7. A Well tool of the character described for cutting material from the wall of a bore, comprising a tubular body, a radially expansible cutter carried by the body, a pair of wedge elements engaging the cutter, both of said elements having Wedge engagement with the cutter and both lbeing movable in opposite directions within the body to eiect radial movement of the cutter by virtue of such movement of the elements in opposite directions, and means for exerting uniform pressures against said elements to uniformly displace them in their cutter actuating movements.

8. A well tool of the character described comprising a tubular body, a radially movable cutter carried by the body, a pair of wedge elements both reciprocally movable Within the body bore in opposite directions and each having Wedge engagement against said cutter to eiect radial movement thereof by virtue of such movement of the elements in opposite directions, and means for maintaining the cutter in expanded position.

9. A well tool of the character described comprising a tubular body, a radially expansible cutter carried by the body, a pair of wedge elements each having wedging engagement with the cutter and both movable in opposite directions within the -body to eiect radial movement of the cutter by virtue of such movement of the elements in opposite directions, yielding means resisting movement of said wedge means in cutter expanding directions, and means for applying fluid pressure to said wedge elements to expand the cutter.

10. A well tool of the character described comprising a tubular body, a radially movable cutter carried by the body, a pair of plungers both reciprocally movable within the body bore in opposite directions and each having a Wedge surface engageable against said cutter to effect radial movement thereof by virtue of such movement of the plungers in opposite directions, and means for applying fluid pressure to said plungers to expand the cutter.

11. A well tool of the character described comprising a tubular body, a radially expansible cutter carried in an opening in the body, a pair of spaced wedge elements each having Wedge surfaces engaging end portions of the cutter and both movable in opposite directions Within the body bore to eiect radial movement oi the cutter by virtue of such movement of the elements in opposite directions, and a fluid conducting tube carried by one of said elements and extending within an opening in the other element for movement relative thereto, said elements being movable toward each other in cutter-expanding directions by iluid pressure within the body against the outer end of one of said wedge elements and communicable through said tube to the outer end of the other of said elements.

12. A well tool of the character described comprising a tubular body, an outwardly movable cutter carried in an opening in the body, a pair of spaced plungers having substantially fluid tight engagement with the body bore and each having a wedge surface engaging an end portion of the cutter, said plungers lboth being movable in opposite directions to effect radial movement of the cutter by virtue of such movement of the plungers in opposite directions, and a uid conducting tube carried Iby one of said plungers and extending within an opening in the other plunger for movement relative thereto, said plungers being movable toward each other in cutter-expanding directions by Huid pressure Within the body against the outer end of one of said plungers and communicated through said tube to the outer end oi the other of said plungers.

13. A well tool of the character described comprising a tubular body, an outwardly movable cutter carried in an opening in the body, a pair of spaced plungers having substantially fluid tight engagement with the body bore and each having a Wedge surface engaging an end portion of the cutter, said plungers both being movable in opposite directions to effect radial movement of the cutter by virtue of such movement of the plungers in opposite directions, a fluid conducting tube carried by one of said plungers and extending within an opening in the other plunger for movement relative thereto, and a coil spring surrounding said tube at the inside of the cutter and bearing against said plungers to resist movement thereof toward each other, said plungers being movable toward each other against the resistance of said spring to expand the cutter by fluid pressure within the body against the outer end of one of the plungers and communicated through said tube to the outer end of the other plunger.

JOHN GRANT.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,878,260 Bunker Sept. 20, 1932 1,921,135 Santiago Aug. 8, 1933 1,544,757 Hufford et al. July 7, 1925 FOREIGN PATENTS Number Country Date '265,507 Great Britain Aug. 8, 1927

Images