US2633331A - Apparatus for preparing a well casing for sidetrack drilling - Google Patents

Description

H. HAMPTON APPARATUS FOR PREPARING WELL CASINGS FOR SIDETRACK DRILLING Filed sept. '7, 194s 4 Sheets-Sheet l .www ,0, y.

INVENTOR.

ff! 5 .4 di, f Y J ATTORNEY H. HAMPTON March 3l, 1953 APPARATUS F'OR PREPARING WELL CASINGS FOR SIDETRACK DRILLING Filed Sept. 7, 1948 4 Sheets-Sheet 2 ATTORNEY 1N V EN TOR.

Harry Hampon Iii- March 31, 1953 H. HAMPTON 2,633,331

APPARATUS FOR PREPARING WELL CASINGS FOR SIDETRACK DRILLING Filed sept. 7, 1948 4 sheets-sneer 5 l 'Z7 l IE A [2L 1% 57 ijf rr Ham fon \Ha y PJNVENTOR.

' Mmmm' March 31, 1953 H. HAMPTON 2,633,331

APPARATUS FOR PREPARING WELL cAsNss FORA SIDETRACK DRILLING Filed sept. 7, 1948 4 sheets-sheer 4 v ig! s i t y y s y. ff/ i 5y? ggf f7` vg if l; l vf.i \/C,/

Harr Ham fon y PINVENTOR.

ATTORNEY Patented Mar. 31, 1953 UNITED STATES PATENT OFFICE PPAnA'rUs Fon PREPAEING A WELL cAsING Foa smE'rRAoK DRILLING Harry Hampton, Burkburnett, Tex. Application September 7, 1948, Serial No. 48,014

(Cl. Z55-1.6)

4 Claims. 1 This invention relates to welldrilling tools and equipment and it has particular reference to new and useful improvements in Whipstocks as Well as to related equipment for installing and adapting the whipstock in a well. .Y f y The principal object of the invention is to provide sidetracking equipment, together `with -a method of installation and use which will simplify a sidetracking job, a procedure which at its best, involves considerable guesswork. The invention seeks not only to eliminate many of the time consuming steps necessary in carrying out a conventional sidetracking operation and thus eiect a material saving in costs butalso to obviate the element of conjecture throughthe provision of means for accurately determining beforehand the exact location in thecasing where sidetracking is to begin. Another object of the invention. is to provi-de sidetracking equipmentl for wells, consisting of an assembly made up of an aligning bar, a slip anchor shearably mounted n the aligning bar, a milling tool on the upper end of the aligning bar and a hydraulic feed unit eiective to shift the bar in the casing of a well to urge the milling tool into operative cutting engagement with the casing to provide a window through which any suitable bit may be passed for thecontinuation of the well drilling operation pastanobstruction in the well. Moreover, the invention includesa whipstock adapted to be lowered by andsheared from the drilling tool or bit to direct thelatter angularly through the window made in the casing, said whipstock havingmeans thereon cooperating With means on the anchor'for orienting the whipstock with the casing window, as well as means by wl'lichtheA whipstock i`s"positivelyvs' cured against rotation and longitudinal displacement in the casing.

Another object of the invention is to provide a process of sidetracking in drillingwhich conF sists in determining the position of .a joint of. casing in a string through Which'drillin'glis' tofb'e sidetracked; establishing an anchor ata prede-` termined point below the proposed sidtracking area; in milling out the casing at the sidetracking area, using the anchor asa guide; in maintaining lateral pressure on the millingtcol during its operation in cutting the casing; inwithdrawing the cuttingA tool from Vthe casing and finally Yin setting a lwhipstock in the casing, o rienting the same witlnthe milled out-area by the anchor.

With the foregoing objects in view, the invention has further reference to certain `features .of accomplishment which will become apparent as the description proceeds, taken in connection with the accompanying drawings wherein: g Y

Figure l is an elevational view showing the aligning bar, anchor and hydraulic feed unit of the invention suspended in a Well casing, the latter being fragmentary and partly in longitudinal section. v

Figure 2 is a view similar to Figure 1 in iwhich the anchor is shown as being set preparatory to the step of milling the casing.

Figure 3 is a view similar to Figures 1 and 2 but in which the milling operation is shown as under way. f V

Figure 4 is a vieW showing the milling operation completed preparatory to setting the whipstock.

Figure 5 is a view of the milled casingshowing the whipstock immediately prior to setting and its attachment by shear pins to a drilling tool.

Figure 6 is a view of the milled casing showing the whipstock installed and its effect in sidetracking the drill pipe.

Figure '7 is a fragmentary sectional view of the whipstock showing its anchoring slip.

Figure 8 is a fragmentary sectional View showing the lower end of the aligning bar andchoke.

Figure 9 is a view partly in section and partly in elevation, showing the milling tool and hydraulic feed unit on a slightly enlarged scale.

Figure 10 is a fragmentary sectional view of the aligning bar showing the anchor thereon in longitudinal section on a slightly enlarged scale. y

Figure 11 is a View in transverse section, taken on line l l--I I of Figure 10. f

Figure 12 is a view similar to Figure 10 showing the anchor with slips extended and illustrating the shear plug by which the position of the proposed sidetracking area is located.

Figure 13 is a transverse sectional View taken on line I3-I 3 of Figure 10.

Figure 14 is a transverse sectional' view taken on line |4I 4 of Figure 9, and Y ,Y Y

Figure 15 is a transverse sectional view taken on line l5-I5 of Figure 9.

Continuing with a more detailed description of the drawing, reference is primarily made to Fig. ures 1 to 4 in which numeral l0 denotes a well casing at the approximate level in a well where drilling must be sidetracked to avoid obstructions of any nature; to straighten crooked holes, or for other reasons. f In Figure 1 is shown the position of the invention initially as preparations are made to cut a windo-w in thecasing l0. The elements ofthe invention consist of an aligning` bar Aor tube Il which has a longitudinal groove I2 extending the full length thereof. Also, the aligning bar II is formed at its lower end with a substantially V- shaped cut-away portion I3 which defines a point I4 at the extremity of the bar on one side. By so forming the end of the bar, it will readily find its position in an anchor I5 when it is found necessary to withdraw the bar after the anchor is set.

The anchor I5 consists of a tubular body which surrounds the aligning bar II at a point spaced above its lower end and is attached thereto by means of shear pins I5 (Fig. 1l). The purpose of these pins will be explained presently. Also, by virtue of a tongue Il formed longitudinally on one side of the bore of the anchor body i5, Iwhich is received by the groove I 2 of the aligning bar II, the bar is held against rotation once the anchor has been set in the casing I D.

The anchor I5 has formed thereon on one side a pair of inclined recesses I8 in which are slidably retained slips I 3. These slips are normally urged to extended position, as shown in Figure 12 by coiled springs and to each slip is attached one end of a latch arm 2I, these arms extending through angular passages 22 communicate with a lateral passage 23 in the wall of the anchor body I5. The inner ends of the latch arms 25 are each provided with a hook 24 which engages under a lip 25 formed at the inner end of the lateral opening 23, as exemplied in F'ure l0.

The opening 23 in the anchor I5 is in register with an opening in the wall oi the aligning bar II (Fig. 10) when the shear pins I6 are intact. A plug 26 is installed in the opening in the aligning bar and is annularly grooved at a to provide a weakened portion intermediate its ends so that it may be readily broken off in the manner to be presently described and for the purpose to be explained. The upper end of the anchor body I5 is interiorly beveled at 2l (Figs. l0 and l2) to receive the pointed guide i4 of the aligning bar Il to facilitate engagement of the bar with the anchor and to eiect alignment of the latters tongue I'I with the groove i2 of the bar i I.

On the upper end of the aligning bar lI is formed a hydraulic feed unit consisting of a body 28, integral with the aligning bar II, which is preferably of elliptical cross-section, as exemplifled in Figure l5. The body 28 has longitudinally spaced openings 29 therein (Fig. 9) in which operate plungers 30, the latter being normally retracted by coil springs 3l but are extended by internally applied fluid pressure in a manner'to be presently explained. The plungers 30 are vslidably disposed in openings 25 which communicate with the bore 3Ia extending longitudinally through the aligning bar II and the body 28. The plungers 3G are biased toward retracted position by the springs 3l. The opposite ends of each spring 3l are connected to a plunger 30 and to a pin or rod SIU, extending across the associated opening 29 and secured to the body A253 by welding or other conventional means.

Threaded into the upper end of the body 28 of the hydraulic feed unit is a shank 32 on which is formed a ball 33, the latter being retained in a socket defined by ball bearings 34, mounted in races spaced apart in the body 35 of a milling tool, the latter having cutter blades 36 spaced about its lower end. It is evident that the ball 33,v suspended as it is by the socketformed by the balls 34, permits the elements of the assembly below the milling tool 35 to be misaligned or disposed at an angle in relation to the longitudinal axis of the casing IIl but such misalignment does 4 not occur until the milling tool 35 is put into operation to cut a window 31 in the wall of the casing I0 (Figs. 4, 5 and 6).

The foregoing description explains the construction and relationship of the parts making up the equipment for installing the whipstccir, which latter is indicated generally by reference numeral 39 in Figures 5 and 6. Specifically, the whipstock consists of the gradually tapered and hardened upper portion which is identified at 38 and the lower or base portion 4U. Extending below the base portion 40 is an aligning element 4I like the lower end of the aligning bar il and which facilitates engagement of the whipstock with the anchor I5 which has been set in the casing.

In one side of the lower portion 40 of the whipstock there is made an inclined recess 42 which slidably retains a slip 43. The slip is normally urged toward engaged position with the casing wall by a coil spring 44 but is restrained by a rod 45 (Fig. 7) which is slidable in an angular bore 45 extending upwardly in the whipstock and is connected to the slip 43 by means of a shear pin 41. The lower end of the rod 45 is adapted to be brought up against the upper end of the tongue Il in the bore of the anchor (Fig. l0) when the whipstock is lowered and guided into the anchor by the member 4I formed on the whipstock. When the rod is moved upwardly in its bore 35 the pin 4l' is sheared off, releasing the slip 43 to the action of spring 44 which urges the slip against the casing wall, thereby holding the same against upward displacement therein. The anchor I5 prohibits downward displacement oi the whipstock while the longitudinal groove @il in its lower end, engaging the tongue Il in the bore of the anchor, prohibits rotative displacement of the Whipstock, hence there is always the assurance that a drilling tool 49 (Fig. 5) by which the whipstock is lowered, will be in alignment with the window 31 which is milled in the wall of the casing l0 when the shear pins 5U connecting the whipstock to the drill are sheared oi by downward weight imposed on the drill pipe 5l.

In operation, the assembly shown in Figures l to 4, that is, the aligning bar II, anchor I5, hydraulic feed unit 28 and milling tool 35, is lowered into the well casing to the approximate depth where sidetracking is to be started. With the assembly so positioned, circulation is eiiected to clean out the hole. Following this operation, it is necessary to determine the location of Vthe particular joint of casing in which a window is to be milled in order to insure against cutting through a coupling and severing the casing string. This is accomplished by running a wire measuring'line 52 (Fig. 1) downwardly through the drill pipe or tubing, thence through the milling tool 35, and the aligning bar ll to the stop plug 26 in the anchor I5. When the plug 26 is encountered by the sinker bar or weight 53 carried by the line 52, the depth of the anchor is made known. When this information is recorded, the sinker bar 53 is used to break off the severable end of the plug 2B (Fig. 12) whereupon the measuring line is continued downwardly through the bottom of the aligning bar II (Fig. 1) and, by virtue of the device 54 carried by the sinker bar, whose radial spring ngers pass freely through the assembly and expand upon emergence therefrom, the upper and lower collars of the casing joint are located, after which the measuring line is withdrawn. The sinker bar 53 may be pulled out with the line if desired leaving the device Min the casing. Or the spring fingers of the device may be sufficiently iiexible so that they may be bent by a relatively strong pull on the line 52 to a downwardly and outwardly extending position so that the device 54 may be withdrawn along with the sinker bar 53. The sinker bar is removed prior to the milling operation while the device 54 may be removed or left in the casing as desired.

After the casing joint couplings have been located as described, the assembly is lowered to a point where the anchor I5 will be disposed at or immediately above the lowest collar. A choke 55 (Fig. 8) is then dropped into the drill pipe and this choke, after passing through the assembly, will come to rest on the annular shoulder 5t formed in the bore of the aligning rod II at its lower extremity. After setting the choke 55, pressure in the drill pipe is built up as well as within the assembly above the choke 55 so that the fluid pressure within the anchor I5 will exert sufficient force against a core 51 (Figs. l0, 12 and 13) in the remaining portion of the plug 26, that this core will be outwardly displaced to impinge the hooked ends of the latch arms 2|, releasing` themvfrom the retaining lips 25, to the action of springs which latter will act to thrust the slips I9 outwardly into engagement with the walls of the casing and thus permanently set the anchor therein.

After setting the anchor as described, pressure in the assembly'is relieved and security of the anchor is determined by raising and lowering the drill pipe, Vafter which, the weight of the drill pipe is set down to shear the pins I G (Fig. 11)

which Vaction will permit free sliding movement of the aligning bar I I through the anchor I5 but rotation of the aligning bar is precluded by the tongue I1 of the anchor lying in the groove I2 of the bar.

Pressure in the assembly is renewed and circulation again started to displace the plungers of the hydraulic feed unit 2B outwardly against the wall of the casing. The milling tool is thereby caused to be moved against the opposite wall of the casing, as shown in Figure 2, after which the milling tool is started rotating to cut the window'31 inthe casing. The self-aligning socket 33 will compensate for misalignment of the aligning bar by the hydraulic feed unit 28, and which misalignment occurs only while starting the cut. The milling tool continues to operate until the window 31 is completed when the hydraulic feed unit comes to rest on the anchor I5. Figure 4 shows the unit 28 approaching this position.

The milling assembly consisting of the aligning bar, milling tool and hydraulic feed unit, is now withdrawn. This assembly can be withdrawn at any time before completion of the window 31 in case another joint of drill pipe is required to be added or to change milling tools. Replacement of the assembly is made readily possible by the self-locating or aligningmember I4 formed on the aligning bar II. Thus, the assembly is returned to the exact cutting position it was in when withdrawn.

To install the whipstock 39, the upper extremity thereof is secured by shear pins 5u to a formation cutter, rock bit, shale bit or other type cutter 49 and is lowered with this bit by the drill stem 5I and the keyway 48 in the lower portion 4I of the whipstock will receive the tongue I1 in the anchor I5, which will orient the tapered side of the whipstock in relation to tnewmdbw which ilaseri'm'med" 1n mei-'easing wall. "When the whipstock is within approxi-v matelyl six inches abovefnal set pbsition,VK the lower end of the plunger A`45'fin'the whipstck set the whipstock in proper position to'direct the bitIIS) outwardly through the window 31 when the pins 50, connecting the Ywhipstock; and bit, have been sheared by therfull. weight of the drill stem.

Manifestly, the construction asshown and de scribed is capableV of some modiication and'such modificationas may be construed to fall within the scope and meaning of the appended claims is also considered to bewithin the spirit and Vintent of the invention.

What is claimed is: 4

l. Apparatus for preparingra well casing for sidetrack drilling, x including an f aligning r bar adapted to be vsuspended inra casing string, an anchor carried by said aligning bar, a milling tool having a longitudinal bore on the upper end of said aligning bar, a swivel forming connection between said milling tool and aligning bar, said bar having a longitudinal bore means on said aligning bar below said milling tool responsive to iiuid pressure within saidbore for displacing said aligning bar in` said casing to urge said milling tool against the wall of the latter, means responsive to fluid pressure within said bore for setting said anchor immovably in said casing, means extending between and connecting said anchor and aligning bar and shearable by weight imposed downwardly on the latter to release said aligning bar for sliding movement through said anchor, a choke removably disposed in said aligning bar for establishing uid pressure in said bores above said choke to actuate said first pressure responsive means and that of said anchor, and means for rotating said milling tool to cut a window in said casing.

r2. Apparatus for preparing a well casing for sidetrack drilling comprising, an aligning bar having a longitudinal bore provided with a longitudinal internal groove; a tubular body disposed about said aligning bar and having a tongue engaging the groove of said bar; shearable pins holding said body in a predetermined position on said aligning bar, spring loaded slips carried by said body; means for holding said slips in retracted position, said body and said aligning bar having registering transverse lateral apertures when said body is in said predetermined position; a shearable plug in said lateral aperture of said aligning bar extending into said longitudinal bore; a core in said lateral aperture of said aligning bar exposed to fluid pressure from within said longitudinal bore when said plug is sheared off and movable by said pressure into said lateral aperture of said body for releasing said holding means and releasing said slips from retracted positions; a hydraulic unit on the upper end of said aligning bar and having a longitudinal bore communicating with said bore in said aligning bar, said unit having a lateral opening communicating with said longitudinal bore; a plunger slidably disposed in said aperture; means biasing said plunger to retracted position within said lateral opening, said plunger being exposed to fluid pressure from within said longitudinal bore and being movable thereby into assenti outwardly extending position to contact the inner Wall of said well casing; a milling tool having a longitudinal bore disposed above said unit; means pivotally and rotatably connecting said milling tool to said hydraulic unit, said means having a longitudinal bore, the bores of said milling tool, said hydraulic unit and said connecting means communicating with one another, said shearable plug being shearable by a weight allowed to descend through said longitudinal bores; means positionable in said longitudinal bore of said aligning bar below -said tubular body to restrict said bore and increase the uid pressure within said tubular bores to move said core and said plunger outwardly after said plug is sheared off, said core actuating said holding means to release said slips and anchor said tubular body in said casing, said plunger moving said unit relative to said well casing to bias said milling tool into engagement with the Wall of said casing; and means for rotating said milling tool to cut a Window in said casing, said pins being shearable by a downward force applied to said milling tool to allow said aligning bar to'. move downwardly with respect to said anchored tubular body as said tool cuts said window.

3. Apparatus for preparing a well casing for sidetrack drilling including an aligning bar having a longitudinal bore, a choke removably disposed in said aligning bar, an anchor releasably attached to said bar, casing engaging slips on said anchor; means for holding said slips in retractable position with respect to said casing, means mounted on said bar extending laterally into said bore and shearable from said aligning bar by a weight descending through said bore, pressure responsive means exposed to fluid pressure within said bore when said last mentioned means is sheared for actuating said holding means to release said slips into casing engaging position, a hydraulic feed unit on said bar `above said anchor, said unit having a longitudinal bore communicating with the bore of said aligning bar, pressure responsive plungers in said unit outwardly extendable by fluid pressure within the internal bore of said unit, spring means holding said plungers normally retracted, a milling tool having a longitudinal bore pivotally and rotatably connected to and above said hydraulic feed unit, said choke establishing fluid pressure in saidbores above said choke todisplace the. pressure responsive means to actuate said holding means and to actuate the plungers of said hydraulic feed unit to urge said milling tool against said casing, means for vertically actuating said aligning bar to release the same slidably with respect to said anchor and means for ro. tating said milling tool to cut a window in said casing.

4. Apparatus for cutting a window in a casing string comprising an aligning bar having .a longitudinal bore; a choke in said bore for estab-v lishing fluid pressure within said bore above said choke; an anchor on said aligning bar; shear pins holding said anchor on said bar; slips on said anchor; means on said anchor for holding said slips in retracted position, means on said aligning bar engageable with said last mentioned means and responsive to fluid pressure within said bore for releasing said slip holding means; a milling tool having a longitudinal bore disposed above and rotatable in relation to said aligning bar and from which the latter is suspended, said bar having a transverse aperture communicating with said bore; means in said aperture also responsive to iluid pressure in said bore and extendable to contact said casing for urging said milling tool against said casing, biasing means for said last mentioned means normally holding said last mentioned means in non-extended position; means for actuating said aligning bar to shear the pins holding said anchor on said bar to release the latter for sliding displacement in said anchor; and means for rotating said milling tool to cut a window in said casing.

HARRY HAMPTON.

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

UNITED STATES PATENTS Number Name Date 1,835,227 Lane et al. Dec. 3, 1931 2,081,294 Eastham May 25, 1937 2,100,684 Carroll NOV. 30, 1937 2,167,194 Anderson July 25, 1939 2,227,347 Johnson Dec. 31, 1940 2,316,409 Downing Apr. 13, 1943

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