US2454839A - Retrieving apparatus - Google Patents

Description

Nov. 30, 1948. R. RING RETRIEVING APPARATUS Filed larch 5, 1w

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WITNESS Patented UNITED STATES PATENT OFFICE RETRIEVING APPARATUS Roland Ring, Houston, TexQassignor to Sperry- Sun Well Surveying Company, Philadelphia, Pa., a corporation of Delaware Application March 5, 1945, Serial No. 581,050

2 Claims. 1

This invention relates to a device for removing whipstocks from bore holes iby a so-called retrieving operation and relates particularly to a device adapted to be included within a drill string above a bit for effecting such results.

The present invention relates to apparatus of the general type illustrated in Kothny Patents 2,107,420, 2,234,438, 2,261,393, 2,296,706 and 2,302,330. Reference may be made to these patents for more complete discussion of the purpose of devices of this type and their manipulations to afiect proper control of a whipstock or the like in a bore hole. In general, such devices comprise members which may occupy alternatively inner or outer positions, in the former of which they are inactive and, being housed within the v boundaries of a drill string, do not interfere with its normal operation. In the latter position, however, they are capable of interengaging with a whipstock or the like so as to control it for rotary movement or, in particular, so as to seize it and effect its withdrawal from the hole.

The present invention relates to features of construction and operation of a device of this type which, so far as ultimate results are concerned, functions the same as devices of said patents. The invention in particular relates to means for the hydraulic control of the engaging elements.

The broad object of the present invention is the provision of an apparatus of the type just indicated which has various advantages over devices of the same general type heretofore known and used. In particular, a positive hydraulic control is provided with a possibility of repetition of the controlling operation.

These and other objects of the invention particularly relating to details of construction and operation will become apparent from the following description read in conjunction with the accompanying drawing in which- Figure 1 is a vertical section through the improved device; and

Figure 2 is a vertical section through the same taken at right angles to the section illustrated in Figure 1.

The retrieving device indicated generally at 2, like those of the patents, is designed to be included as part of the drill string near the lower portion thereof, which drill string carries, for example, a whipstock 50 secured thereto initially by the usual shear pin 54. The whipstock is provided with a collar 48 through which the drill stem may pass during the procedure of drilling off the whipstock and which collar is adapted to be engaged by expandible means incorporated in the device.

The device is provided with threaded openings 4 and 6 into which the adjacent drill stem sections are arranged to be secured and which provide passages for the drilling liquid which passes through the device through a pair of channels indicated at 8.

The expandible elements of the device take the form of levers ill provided as described in the patents mentioned above with soft rivets l2 for conventional purposes and pivoted loosely upon pins [4, the bottoms of the openings containing thclevers l0 being adapted to take the strains of whipstock removal rather than the pins. A spring arrangement indicated at 16 urges the levers l0 outwardly but they are at suitable times held inwardly by the engagement of hooks l8. thereof with latching members 28, carried by a plunger 22 which is supported by a rod 24 extending through a suitable stuffing box assembly indicated at 26 and held upwardly by a spring 30 acting beneath a head 28 of the rod 24. As will be noted from Patent 2,302,330 the arrangement so far described is identical with that illustrated in the patent.

In accordance with the present invention the upper end of the rod 24 carries a member 32 which takes the form of a piston slidable in a central bore of the device. The upper end 34 of this piston is provided with a central cylindrical opening 36. The sides of the piston adjacent to the upper ends of the channels 8 are provided with openings 38 so that normally free flow of mud may take place through the opening 36 outwardly through the openings 38 and thence through the channels 8 into the bores of the lower sections of the drill string. The piston 32 carries internally a pair of springs 40 to which are secured blocks 42 which pass through openings in the piston wall and engage, as illustrated particularly in Figure 2, downwardly divergent conical or sloping walls 44 in the upper portion of the bore. When the parts are in the positions illustrated in the drawing, these springs are forced inwardly so as to overlap the peripheral portions of the opening 36, the springs normally tending to move outwardly so as to cause themselves and the blocks to clear that opening.

In the use of this arrangement, the collar 48 of the whipstock 50 extends above the position of the upper ends of the engaging members it], which occupy the outward positions indicated in chain lines, being received in longitudinal slots 52 in the whipstock collar 48, desirably with close clearance so that upon rotation of the whipstock through the engaging-members id rather than through a shear pin 54 which, below the level of the sub 2, secures the'whipstock 50 to a drill collar or iblt 56. Thus assembled, the whipstock, bit- 56 and sub 2 and other elements, including for example an orientation sub located above sub 2,

are lowered on a sectional drill stem to approximately the depth at which the 'whipstock will be ultimately fixed. The drill stem andthe parts carried thereby may now be rotated while a well surveying instrument is lowered through the same to a position to make a record of orientation, for example, in accordance with Hyer Patent taken by the hardened engaging members rather than by the relatively weak shear pin 54, which must ultimately be sheared ofi. When the surveying instrument reaches its proper level, the drill stem may be moved up and down, i. e., spudded, so that torsional strains are taken out of the assembly and then the entire assembly is held at rest for sufficient time for the surveying instrument to make a record. At this time, the position of the rotary table may be noted at the surface.

As soon as sufilcient time has elapsed for the making of the record, the surveying instrument may be withdrawn by its supporting wire line, or retrieved by means of an overshot if it was originally dropped in go-devil fashion, and during such withdrawal the drill stem may be again r0- tated, at which time the stresses of rotation will again be assumed by the engaging members Ill. After the record is analyzed and the proper position of the drill stem ascertained, the rotary table may be turned to a position, as determined by the marks thereon and the record of the surveying instrument, to bring the whipstock 50 to the desired position, whereupon spudding is again effected to insure that stresses in the system are removed and the whipstocktfl properly lined up.

Following this, the weight of the drill stem is caused to rest on the shear pin 54, first driving the whipstock 50 into the earth at the bottom of the bore hole to anchor it, and thereafter shearing ed the pin 54 so that drilling may be accom'-' plished.

The whipstock under these circumstances, and as indicated in Patent 2,298,706, desirably has a tapered or conical region shown at 58 at the lower portion of its collar, so that as the sub moves downwardly, the rivets l2 will engage this surface, with the result that the engaging members III are cammed inwardly against the pressure of the spring l6. As this inward movement occurs, the rounded ends of the latch extension l8 will ride over the beveled portions of extensions 20, camming the member 24 downwardly until they move inwardly to a sufflcient extent to clear these members, whereupon the member 24 will be moved upwardly by the action of spring to latch the engaging'members id in their inner position. As the sub moves further downwardly, if the most restricted portion of the whipstock collar 48 is too small for the passage of the rivets l2, they will be sheared ofi. Even if they are not sheared off at this time, however, they will in general be worn or broken away during the subsequent drilling.

Except for the possible continued projection of the rivets l2, the subnow presents a cylindrical aspect, and consequently drilling may occur down the face of the whipstock in usual fashion During such rotation, stresses are fwithout engagement of any projecting-parts with thewhipstockor earth.

So long as the members III are intended to occupy inner positions the parts occupy the positions illustrated in the drawing, the members I [I then being latched against outward movement. When, however, it is desired to cause said members- Ill to move outwardly, a ball 48 ofa size closely fltting the cylindrical "opening at is dropped through the drill stem, being introduced at any suitable point inthe mud circulating system. Before it enters the opening 36 the mud flow is unimpeded. when, however,.it reaches the position illustrated in Figure 2, it substantially fills the opening while resting on the upper ends of the springs 40. when this occurs the mud flow is interrupted and a rise in pressure at the mud gauge at the surface will then indicate the attainment'of this position. As the pump continues to operate, the ball 46 andthe head 34 will be subjected to mud pressure as a unitary piston. Consequently, this assembly will be driven downwardly by hydraulic pressure releasing the latches lil by causing disengagement of the retaining elements 20 from the hooks [8 thereof. The latches or elements in willthen be forcibly moved outwardly by the sprin arrangement it. As downward movement of the assembly occurs, however, the blocks 42 will become free to move outwardly by reason of their entering the expanding portions of the bore at 44. As a consequence they will open after sufflcient downward movement releasing the ball 48 which may then drop between the springs into the lower portion of the cylinder 32. When this occurs the pressure upon the upper end of the movable assembly is relieved, with the result that the spring 30 may again drive it upwardly so that the members 20 are again in position to latch inwardly the members or latches ill if the same are cammed inwardly by downward movement through the whipstock collar 68 as described above and in the patents referred to. At the same time it will be evident that the device is reset for subsequent operation by another ball. In this fashion a plurality of operations may be secured, the space for receiving the used balls being sufllciently enlarged to accommodate the desired number. It willalso be evident that after the operation occurs the mud flow is completely unimpeded, This fact, while highly desirable so that drilling may be resumed without diminution of the mud flow, is also of importance in connection with the signal which is given to the operator of the proper operation of the retrieving apparatus. In other words, he will note at the surface a momentary substantial increase of pressure indicative of the location of the ball at the opening 36 followed by a drop of the presbore hole comprising a body arranged to be included in a drill string above the bit, means carried by said body and expandible outwardly to Y engage a whipstock or the like, and means operable by liquid pressure to release said expandible means, said means comprising a member providing a piston normally providing free passage of liquid but arranged to be closed by an element lowered through the drill string to restrict flow and provide a closed piston movable under liquid pressure, movement of said member releasing said element so that the passage of liquid is thereafter unimpeded and so that the member may then move to its original position capable of a subsequent operation upon lowering of. another element.

2. Means for retrieving a whipstock from a bore hole comprising a body arranged to be included in a drill string above the bit, means carried by said body and expandible outwardly to engage a whipstock or the like, and means operable by liquid pressure to effect outward movement of said expandible means, said means comprising a member providing a piston normally providing free passage of liquid but arranged to REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,653,900 Gregory Dec. 27, 1927 2,207,649 Williams et a]. July 9, 1940 2,302,330 Kothny Nov. 17, 1942

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