US3339636A

US3339636A - Whipstocks

Info

Publication number: US3339636A
Application number: US402446A
Authority: US
Inventors: Thomas M Frisby
Original assignee: Eastman Oil Well Survey Co
Current assignee: Eastman Oil Well Survey Co
Priority date: 1964-10-08
Filing date: 1964-10-08
Publication date: 1967-09-05
Anticipated expiration: 1984-09-05

Description

Sept. 5, 1967 T. M. FRlsBY 3,339,636

Y wHIPsTocKs Filed octj s, 1964 2 sheets-sheet 1 /7/1 wv//Z ff ff? Sept. 5, 1967 T, M. FRlsBY 3,339,635

wHIPsTocKs Filed Oct. 8, 1964 2 Sheets-Sheefc, 2

United States Patent 3,339,636 WHIPSTOCKS Thomas M. Frisby, Houston, Tex., assignor to Eastman Oil Well Survey Company, Houston, Tex., a corporation of Delaware Filed Oct. 8, 1964, Ser. No. 402,446 7 Claims. (Cl. 166-117.5)

This invention relates to sidetracking assemblies for deviating a bore hole, and more particularly to circulating sidetracking assemblies.

In the past, circulating sidetrack assemblies of various types have been proposed and some have been used. These assemblies generally include a whipstock and a drill collar which is released from the whipstock after it is set in position in the hole, usually on a cement plug. Drilling uid is circulated through a suitable bypass to the bottom of the whipstock to wash the hole as the tool is run in, and make certain that it seats properly on bottom. This bypass arrangement must be closed when the drill collar is released from the whipstock.

One previous method proposed for releasing the drill collar from the whipstock and closing the bypass uses pressure of circulating Huid and requires that a ball be dropped into the collar to actuate the valve means. This system has a disadvantage of requiring that the whipstock be off bottom when the ball is dropped in the hole, las the kelly must be removed from the drill pipe to insert the ball. Once the ball is inserted, the tool is committed and no further washing is possible before releasing the collar from the whipstock. Thus, if diculty is experienced in returning the whipstock to bottom, the tool must be pulled and rerun.

Other proposed sidetracking assemblies have relied upon an increase in pressure over the circulating pressure to open a valve and permit circulating of liuid through the bit on the bottom of the collar. This limits the amount of pressure which may -be utilized for circulation as the tool is lowered into the hole.

In general, prior art sidetracking assemblies have required tortuous flow paths for the circulating iiuid.

An object of this invention is to provide a sidetracking device which overcomes the above disadvantages of prior proposed sidetracking devices.

Another object is to provide a sidetracking device in which the ow path of fluid through the device is substantially straight to provide minimum washing action.

Another object is to provide a sidetracking device in which the drill collar is released from the whipstock and the uid ow path diverted from circulating the whipstock to the bit in the bottom of the drill collar by relative movement of the drill collar and whipstock.

Another object is to provide a sidetracking device in which the drill collar is released from the whipstock and the uid flow path diverted from the whipstock to the lower end of the collar purely by mechanical means while the whipstock is resting on bottom.

Another object is to provide la sidetracking means in which full pressure can be used to circulate and the whipstock remains on `bottom while carrying out all operations relative to releasing the drill collar from the whipstock.

Other objects, features and advantages of the invention will be apparent from the drawings, the specification and the claims. i

In the drawings, wherein an illustrative embodiment of this invention is shown, and wherein like reference numerals indicate like parts:

FIGURE l is a view partially in elevation and partially in cross-section of a sidetracking device embodying this invention;

FIGURE 2 is a View in vertical cross-section through 3,339,636- Patented Sept. 5, 1967 the center section of the drill collar of the device as shown in FIGURE l, an-d the associated portion of the whipstock and illustrating the whipstock, drill collar 'and control sleeve in the position in which they are run into the well;

FIGURE 3 is a view similar to FIGURE 2, illustrating the position of the whipstock, drill collar and sleeve after the drill collar has been moved downwardly to release it from the whipstock and before the sleeve has been released from the whipstock; and,

FIGURE 4 is a view similar to FIGURES 2 Iand 3 illustrating the position of the whipstock, drill collar and sleeve after both the drill collar and sleeve have been `released from the whipstock and the drill collar has moved Kdownwardly toward drilling position.

The whipstock indicated generally at 10 is conventional in form and includes the guide 11 at its upper end through which the drill collar indicated generally at 12 extends.

Stabilizing ribs 9 are provided on the drill collar to stabilize the drill collar as is well known to those skilled in the art. On the lower end of the drill collar 12 a conventional 'bit 14 is provided.

The drill collar 12 is secured to the whipstock 10 by any desired mechanical means which can `be released upon downward movement of the Adrill collar 12 relative to the whipstock 10. Preferably this mechanical means is the shear pin 13 which is threadedly Lreceived in the whipstock and drill collar to fasten them together. When the whipstock is set on bottom, such as on a cement plug, downward movement of the drill collar relative to the whipstock will shear the pin 13 and release the drill collar from the whipstock.

The drill collar has a bore 14 extending therethrough for conducting drilling fluid from the drill pipe above the collar down to the whipstock while the tool is being run land to the bit 14 when the sidetracking operation begins. The bore 14 includes a counterbore 15 to provide a small-diameter section of the bore in the upper section of the drill collar portion shown and a large-diameter section in the lower portion for Ia purpose hereafter eX- plained.

A valve seat 16 is provided in the lower portion of the bore. The seat includes the flow passageways 16a through which fluid is conducted to bit 14 while drilling.

A sleeve 17 slidable relative to the drill collar 12 is provided and is preferably positioned within the drill collar bore 14 and counterbore 15. This sleeve 17 carries a valve member 18 on its lower end which surrounds the solid nose of the valve seat 16 and cooperates with the outer periphery of valve seat 16 to seal between the valve member and valve seat and prevent flow downwardly through the drill collar with the sleeve in the' position shown in FIGURE 2. In the form of the invention illustrated, the valve seat 16 includes the resilient ring 19 to seal between the valve member and valve seat.

To permit removal lof the sleeve 17 and the value seat 16 to replace the seals thereon and to replace the valve seat and sleeve in the event of wear, the Valve seat is held between a shoulder 21 in the drill collar 12 and a snap ring 22. After the snap ring 22 is removed, the valve seat 16 and sleeve 17 may be removed through the bottom end of the drill collar.

A suitable bypass is provided for conducting uid from the bore through the drill collar 12 to the bottom of the whipstock. This bypass includes the port 23 in the sleeve 17 :and the bypass opening 24 through the drill collar 12. The bypass 24 communicates with a passageway 25 in the fitting 26 through a shear sleeve 27. Suitable O-

rings

28 and 29 seal between the sleeve 27, fitting 26 and drill collar 12, respectively.

A pipe 31 extends from the fitting 26 downto the bot.- tom of the whipstock as shown in FIGURE 1, to deliver 3 v drilling iiuid to the bottom of the whipstock to insure proper circulation of iluid during running of the tool.

Sleeve 17 carries O-

rings

32a and 33a which straddle the bypass 24 with the sleeve in the position illustrated in FIGURE 2 to confine flow of uid when it is passing through the bypass. An additional O-ring 34a is provided below the O-ring 33a and, when the sleeve is shifted upwardly relative to the drill collar, the

seals

33a and 34a bridge the bypass 24 to prevent flow of fluid therethrough as shown in FIGURE 3.

Means are provided for securing the drill collar 12 and the sleeve 17 to the whipstock. Preferably, two separate means are provided. As noted above, one means may be provided by the shear pin 13 threadedly securing the whipstock and drill collar together; the shear sleeve also secures the whipstock and collar but its primary purpose is to form a seal in the bypass across the area between the whipstock and collar. The preferred form of separate means for securing the sleeve to the Whipstock is provided by a second shear pin 32. This shear pin is threaded to the sleeve :as shown with the head of the shear pin in hole 33 in the whipstock.

The shear pin extends through an elongate slot 34 in the drill collar to form a lost motion connection between the whipstock and collar. When the drill collar and whipstock are secured together by the shear pin 13, the whipstock-sleeve shear pin 32 is at the bottom of the slot 34 as illustrated in FIGURE 2. Thus, it will be 'appreciated that downward movement of the drill collar after shear pin 13 has been sheared is permitted by reason of the lost motion connection between whipstock and collar while the sleeve 17 is still secured to the whipstock, to move the parts into the position shown in FIG- URE 3. At this time, a detent indicated generally :at 35 engages an annular slot 36 in the exterior of sleeve 17 to hold the sleeve and drill collar in the relative positions shown in FIGURE 3.

Upon the drill collar moving downwardly relative to the whipstock to the position shown in FIGURE 3, the upper portion of slot 34 engages the shear pin 32 and further downward movement shears this pin to release the sleeve from the whipstock. This relationship is illustrated in FIGURE 4, wherein both the drill collar and sleeve have been released by the shearing of both pins and the drill collar is free to move downwardly along the whipstock for normal drilling operations.

It will be noted that the sleeve 17 is provided with an O-ring 36 on the reduced diameter section of the sleeve at its upper end. With the valve in its unseated position, fluid pressure is applied to opposite ends of sleeve 17 and, as the effective area of seal 34 at the bottom of the sleeve is larger than the effective area of seal 36 at the top of the sleeve, there results an upward force urging the sleeve toward unseated position to provide with the detent 35 a safety means for preventing reseating of the valve 18 on seat 16.

In operation, the tool is run in the condition illustrated in FIGURES 1 and 2 with the two shear pins securing the whipstock, sleeve and drill collar together, and with the shear sleeve 27 establishing communication between the bypass 24 and the conduit 31. Circulation of uid is carried out as the device is lowered into the hole to wash the tool down. As the tool comes to rest on bottom, further release of the weight of the string will apply a force to the drill collar 12 which will urge it downwardly relative to the whipstock 10, and shear pin 13, and bypass sleeve 27, as illustarted in FIGURE 3. As the drill collar moves downwardly relative to the whipstock, the detent 35 will engage the slot 36 to hold the sleeve in elevated position relative to the drill collar so that the valve member is free from the valve seat and uid being pumped down through the drill string will pass through the passageways 16a in the valve seat member, and thence through the bit 14 for normal drilling operations.

Further downward movement of the drill collar will engage the top of slot 34 with the shear pin 32 and shear this pin to release the sleeve from the whipstock as indicated in FIGURE 4. With the parts in the position indicated in FIGURE 4, the sleeve 17 is in its raised position to permit free flow throughthe flow passageways 16a in the valev seat and thence to the bit for normal drilling operations. The O-

rings

33 and 34 straddle the bypass 24 to prevent loss of fluid through the bypass. The sleeve 17 remains in the position shown in FIGURE 4 due to the detent 35 and to the pressure differential across the sleeve which urges the sleeve in the upward direction.

The foregoing disclosure and description of the invention are'illustrative and explanatory thereof, and various changes in the size, shape and materials, as well as in the details of the illustrated construction, may be made within the scope of the appended claims wtihout departing from the spirit of the invention.

What is claimed is:

1. A sidetracking assembly comprising:

a whipstock,

a drill collar having a bore therethrough,

a valve seat in said bore,

a sleeve slidable relative to said drill collar,

a valve member carried by said sleeve and cooperable with said valve seat to prevent flow through said bore with the sleeve in one position relative to the drill collar,

means including a bypass in the collar in uid communication with the bore with said sleeve in said one position conducting uid to the lower end of the whipstock,

a first securing means securing the drill collar to the whipstock and operable upon downward movement of the drill collar relative to the whipstock to release said trst securing means,

a second securing means securing the sleeve to the whipstock and extending through the drill collar with a lost motion connection which permits release of the rst securing means and movement of the sleeve to a second position within the drill collar to unseat the valve member from said valve seat prior to release of the second securing means,

said second securing means being operable upon further downward movement of the drill collar relative to the whipstock to release said second securing means,

and means on said sleeve closing said bypass when said sleeve and said drill collar are in said second position.

2. A sidetracking assembly comprising:

a whipstock,

a drill collar having a bore therethrough,

a valve seat in said bore,

a sleeve slidable relative to said drill collar,

a valve member carried by said sleeve and cooperable With said valve seat to prevent ow through said bore with the sleeve in one position relative to the drill collar,

means including a bypass in the collar in uid communication with the bore with said sleeve in said one position conducting fluid to the lower end of the whipstock,

a first securing means including a shear pin and a shear sleeve securing the drill collar to the whipstock, said securing means releasing said drill collar from the whipstock upon movement of the drill collar relative to the whipstock,

a second securing means securing the sleeve to the whipstock and extending through the drill collar with .a lost motion connection between the whipstock and the collar,

means on said drill collar shearing said second securing means and releasing said sleeve from the whipstock after the drill collar has been disconnected from the first securing means and has moved a selected distance relative to the sleeve to move the sleeve to a second position and thereby unseat said valve member from said valve seat,

3. A sidetracking assembly comprising:

a whipstock,

a drill collar having a bore therethrough,

a valve seat in said bore,

a sleeve slidable in the bore,

a valve member on said sleeve cooperable with said valve seat to prevent ow through the bore with the sleeve in one position relative to the drill collar,

means including a bypass in the collar in uid communication with the bore with said sleeve in said one positionconducting fluid to the lower end of the whipstock,

a first shear pin securing the drill collar to the whipstock,

a second shear pin securing the sleeve to the whipstock,

means on said drill collar shearing said second shear pin after said first shear pin has been sheared and the drill collar has moved a selected distance relative to the sleeve to a second position to unseat said valve member from said valve seat,

`and means on said sleeve closing said bypass when said sleeve and drill collar are in said second position.

4. The assembly of claim 3 in combination with means for holding said sleeve in said second position after said second shear pin has been sheared.

S. The assembly of claim 3 wherein said bore is smaller at one end than at its other end and sliding seals are provided on the sleeve engaging said different-diameter bore sections to provide a differential area urging said sleeve valve away from said valve seat.

6. A sidetracking assembly as set forth in claim 1, together with a locking means between the sleeve and drill collar and engageable when the sleeve is moved to said second position for locking the sleeve in said second position after the second securing means has been released.

7. A sidetracking assembly as set forth in claim 2, wherein said shear sleeve which forms part of the bypass in the collar is disposed in said bypass to extend across the area between the drill collar and the whipstock.

References Cited UNITED STATES PATENTS 2,567,507 9/1951 Brown 166--117.5 2,770,444 11/1956 Neal 166-117.5 2,978,032 4/1961 Hanna l66-117.5 3,174,549 3/1965 Anderson 166-1 17.5 3,194,327 7/1965 Smithson 175-61 CHARLES E. OCONNELL, Primary Examiner.

JAMES A. LEPPINK, Assistant Examiner.

Claims

1. A SIDETRACKING ASSEMBLY COMPRISING: A WHIPSTOCK, A DRILL COLLAR HAVING A BORE THERETHROUGH, A VALVE SEAT IN SAID BORE, A SLEEVE SLIDABLE RELATIVE TO SAID DRILL COLLAR, A VALVE MEMBER CARRIED BY SAID SLEEVE AND COOPERABLE WITH SAID VALVE SEAT TO PREVENT FLOW THROUGH SAID BORE WITH THE SLEEVE IN ONE POSITION RELATIVE TO THE DRILL COLLAR, MEANS INCLUDING A BYPASS IN THE COLLAR IN FLUID COMMUNICATION WITH THE BORE WITH SAID SLEEVE IN SAID ONE POSITION CONDUCTING FLUID TO THE LOWER END OF THE WHIPSTOCK, A FIRST SECURING MEANS SECURING THE DRILL COLLAR TO THE WHIPSTOCK AND OPEABLE UPON DOWNWARD MOVEMENT OF THE DRILL COLLAR RELATIVE TO THE WHIPSTOCK TO RELEASE SAID FIRST SECURING MEANS, A SECOND SECURING MEANS SECURING THE SLEEVE TO THE WHIPSTOCK AND EXTENDING THROUGH THE DRILL COLLAR WITH A LOST MOTION CONNECTION WHICH PERMITS RELEASE OF THE FIRST SECURING MEANS AND MOVEMENT OF THE SLEEVE TO A SECOND POSITION WITHIN THE DRILL COLLAR TO UNSEAT THE VALVE MEMBER FROM SAID VALVE SEAT PRIOR TO RELEASE OF THE SECOND SECURING MEANS, SAID SECOND SECURING MEANS BEING OPERABLE UPON FURTHER DOWNWARD MOVEMENT OF THE DRILL COLLAR RELATIVE TO THE WHIPSTOCK TO RELEASE SAID SECOND SECURING MEANS, AND MEANS ON SAID SLEEVE CLOSING SAID BYPASS WHEN SAID SLEEVE AND SAID DRILL COLLAR ARE IN SAID SECOND POSITION.