US2207920A - Expanding foot piece for whipstocks - Google Patents

Description

July 16, 1940. J, HUGHES 2,207,920

EXPANDING FOOT PIECE FOR WHIPSTOCKS Filed 001;. 28, 1937 Patented July 16, 1940 UNITED STATES PATENT OFFICE 2,207,920 EXPANDING FOOT PIECE FOR WHIPSTOCKS Application October 28, 1937, Serial No. 171,465

1 Claim.

which may be lowered into the well bore anchored in position to cause deflection of the drill bit and thereafter the anchoring portion thereof released and the whipstock removed from the well bore along with the drill bit.

In directional drilling it is desirable to set the whipstock in the well bore in a predetermined and oriented position so as to direct the well bore in the desired manner. The practice has therefore grown up of inserting the drill bit and the whipstock into the well bore as a unit and orienting the whipstock so that the deflecting face will direct the drill bit in .the desired manner. It "is of course necessary to anchor the whipstock so that when the drill bit is released therefrom to perform the drilling operation that the whipstock may be securely anchored in position.

The present invention contemplates an expanding foot piece or anchor for the whipstock which can be set to hold the whipstock in the desired predetermined position and which may thereafter be released so that the whipstock may be readily removed.

7 Another object of the invention is to provide a wedge type anchor for removable whipstocks.

Still another object of the invention is to provide 'a telescoping foot piece for whipstocks so that it may be wedged in position in the well bore to anchor the whipstock;-

Still another object of the invention is to ofl'set a whipstock in a well bore by moving the base thereof. laterally in the direction in which the well bore is to be deflected.

Other and further objects of the invention will be readily apparent when the. following description is considered in connection with the accompanyingdrawing wherein:

Fig. 1 is a vertical sectional view of the whip stock assembled and ready for connection to the drill bit. I

Fig. 2 is a side elevation of the whipstock lowered into position and set in the well bore with the drill hit in-position to be released thererom.

Figs. 3 and are sections taken on the lines 33 and 44 of Fig. 1, respectively.

Fig. 5 is a bottom plan view of the whipstock showing "the arrangement of the teeth thereon to hold the whipstock in position. r The upper end of. the whipstock is of the general type shown in the patent to McVicar, 1,910,761, granted August 21, 1934, and includes a collar 2 which has a passage 3 therethrough to receive the drill stem 4. The drill stem has a (Cl. 255-1) The invention relates to a whipstock of. the type drill bit 5 connected thereto. A pin I is arranged to pass through the opening 8 in the collar 2 and in this manner the whipstock is fastened to the drill stem so that the assembly may be lowered into the well bore. This pin prevents relative rotation of the whipstock with respect to the drill stem so that if it is desired to orient the drill stem into position the operator is assured that the whipstock will be fixed in the" desired and predetermined direction when his orientation has been completed. Of course, the pin 1 is arranged to shear when a suflicient weight is placed upon the drill stem so that the drill bit may advance to cut away the side 10 of the well bore II.

The whipstock l2 includes the body portion l3 which has the inclined deflecting face ll thereon. This body I2 may be of any desired length or configuration and the angle of the deflecting face It may be varied for diiferent whipstocks. depending upon the angle of deflection which is desired.

In order that the whipstock maybe readily anchored in position when it reaches the desired elevation a foot piece has been connected thereto. This'foot piece has a toothed lower end 2! so'that it may bite into the bottom 22 of the well bore II and is of a diameter to flt into the well bore. This piece has a wedged or tapered face 23 thereon which is inclined with respect to the longitudinal axis of the whipstock and the foot piece. This face 23 may have a dovetail groove 25 therein which is arranged to flt with a dove-tail'tongue 26 which is provided on the lower tapered end 21 of the whipstock body l3. In this manner there may be relative sliding movement between the foot piece and the whip- .stock, and as seen in Fig. 2, when the foot piece is anchored against the well bore, pressure applied to the whipstock body l3 will cause it to slide along the face 23 to assume the expanded position there shown, in that the whipstock will be moved to the left so that the heel 30 thereof will wedge against the side of the well bore and at the same time the foot piece 20 will be wedged against'the opposite side 3| of the well bore. This sliding movement will'also move the base of the whipstock to the left so that the deflecting face It assumes a greater inclination than its normal angle of inclination with respect to its longitudinal axis of the well bore. In this manner the angle of. deflection may be increased somewhat.

A retainer pin 40 is carried by the foot piece 20 and as seen in Fig. 1 it projects into the dovetail groove 25 The tongue 26 on the lower end of the whipstock is cut away to provide a space 33 which terminates in the upper shoulder 34 and the lower shoulder 35. In this manner the relative sliding movement of the foot piece and the whipstock is limited. In the upper position the whipstock may be lowered into the well bore and in the lowermost position, as shown in Fig. 2 the foot piece limits the downward movement of the 30 from engagement with the well bore and to allow the foot piece to telescope along the bottom 21 of the whipstock to its retracted position. In

I this manner the whipstock is readily removable.

Anydesired means may be provided to prevent inadvertent telescoping of the foot piece until a predetermined pressure is exerted thereon.

Broadly, the invention contemplates a removable type of whipstock which can be lowered into the well bore and anchored into position and readily withdrawn by merely lifting up on the whipstock.

What is claimed is: I

A retrievable whipstock including a body, means at the top thereof to receive the drill stem and drill bit for lowering and retrieving the whipstock, a deflecting face on said body, a tapered bottom on said body inclined across from the back, a dovetailed tongue projecting from said bottom, a cutaway portion between the ends of said tongue to provide spaced stop shoulders, a

. foot piece, a top face thereon which is complementary to said bottom, a dovetail groove to receive said tongue to slide therein, and a stop pin projecting into said groove to be abutted'by said shoulders to limit the movement of the body relative to said foot piece and to suspend the foot 20 piece on the body during lowering and retrieving.

JAMES D. HUGHES.

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