US 2858107 A
Description (OCR text may contain errors)
lC- 28, 1958 A. J. coLMr-:RAUER 2,858,107
METHOD AND APPARATUS FOR COMPLETING OIL WELLS y/AWM Lg. 2 //Of IH Il INVENToR. ANDREW J. co/.MERAUER BY @-dwwf A #orne y Oct. 28, 1958 A. J. coLMl-:RAUER 2,858,107l
METHOD AND APPARATUS FOR COMPLETING OIL WELLS Filed sept. 26, 1955 4 sheets-sheet 2 IN V EN TOR.
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Oct. 28, 1958 A. J. coLMx-:RAUER 2,858,107
METHOD AND APPARATUS FOR COMPLETING OIL WELLS Filed Sept. 26, 1955 4 Sheets-Sheet 3 l l l l Z4- l l l l ,l 23 V/ l i f* g i 25 I 32 e/w A 1,---4
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IN V EN TOR. ANDREW J. COLMERAUE'R By Q Oct. 28, 1958 A. .1.l coLMERAUr-:R 2,858,107
METHOD AND APPARATUS FOR COMPLETING OIL WELLS Filed Sept. 26, 1955 38 4 Sheets-Sh 4 Fig. 8 Fig. Io
INVENTOR. ANDREW J. COLMERAUER United States atent METHGD AND APPARATUS FOR COMPLETING OIL WELLS Andrew J. Colmerauer, Redondo Beach, Calif. Application September 26, 1955, Serial No. 536,589
3 Claims. (Cl. Z55-1.6)
This invention relates to method and apparatus for completing the drilling of oil wells wherein one or more drain holes are drilled outwardly and laterally from the well bore.
More particularly, the invention relates to method and apparatus whereby there is provided a permanent whipstock-locating collar and a removable whipstock.
Heretofore it has been the practice, when drilling a series of vertically spaced laterally extending drain holes, to set. an oriented whipstock at each successive level where a lateral drain hole is to be drilled. Thus the several drain holes are spaced and directed so as to drain an area of some 360 degrees around the main vertical bore of the well. When it becomes necessary to reenter one. or more of the lateral drain holes for some remedial purpose, there is no means provided for quickly and accurately locating each of the drain holes.
The principal object of the invention is to provide means whereby any one or more of a series of lateral drain holes which have been drilled previously, can be readily located at some later time, such as when it is desired to pull a liner or insert a new liner or to clean out the drain hole.
Another object of the invention is to provide a permarient seat for a llexible perforated liner for a drain hole which is drilled into loose, unconsolidated oil sands.
Another object is to provide a seal between a ilexible liner and a` liner seat to. prevent the entrance of sand into the main well bore.`
In the drawings, Figure l illustrates the lower end of a well after the casing has been run but before it has been cemented and before the lateral drain holes have been drilled.
Figure 2, is a vertical elevation, partly in cross section, illustrating the lower end of the well during the cementing operation.
Figure 3 illustrates the` lower end of the well after a whipstock has `been set in place and a lateral drain hole has been drilled.
Figure 4 is a vertical elevation, in cross-section, of a whipstock for use with the present invention.
Figure 5V is a vertical elevation of the whipstock illustrated in Figure 4 turned 90 from the View shown in Figure 4.
Figure is a vertical cross-section of the locating collar 7.
Figure 7 is a cross-section of the locating collar taken on line 7-7 of Figure 6.
Figure 8 is a vertical cross-section of the lower end of the whipstock of Figure 4 showing the locking linger.
Figure` 9 is a cross-section taken on line 9-9 of Figure 8.
Figure 10 is a vertical cross section of the locking sleeve attached to the upper end of the whipstock, Figure 4.
Referring to Figure l ofthe drawings, the numeral 1 indicates the bore of a well which has been under- `the position shown in Figure 3.
reamed to form an enlarged cavity 2 in the formation from which oil is to be produced through lateral drain holes. A well casing 3 has been run into the well and may be set on bottom or may be provided with a perforated liner 4 on the lower end thereof.
The casing 3 is provided with usual casing shoe 6 and a special pernzianent whipstock-locating collar 7 above the shoe. Above the collar l the casing is: provided with either a casing guide (not shown) or an upwardly-open flexible cementing basket 8. Above the basket d there is provided a cementing collar 9 having side ports l1. Above the collar 9 a downwardly-opening flexible cernenting basket l2. is slidably mounted around the casing 3; The flexible sides lli of the basket l2 are held in closed position while running the casing into the well, by means ot frangible retaining wires i4 and l5 which extend through the interior of the casing 3. Wire 14 holds the basket l?. against vertical movementy while wire l5 holds the flexible springlike sides of the basket in closed position. This is a commonly used arrangement wherein the wire is wrapped around the outside of the basket with one end o-f the wire extending through perforations in the wall of the casing. When the pipe 16, or other object, is passed downwardly through the casing 3 the end of the wire which extends diametrically through the casing is ruptured.
The casing 3 is provided vwith one or more open ports il@ located at a point slightly below the upper end' ofthe enlarged cavity 2. The well is normally filled with drilling fluid as indicated.
The cementing operation is performedin two stages, as follows:
First stage-After the casing 3 has been run to bottom, tubing or drill pipe 16 having on its lower end a straddle too-l or a downwardly facing swab cup 17 is run in the casing to some desired point above the top of the enlarged cavity 2. An upper stage cementing collar (not shown) having side ports is located in the casing string at this point, usually with a cementing basket (not shown) below it. Cement slurry is pumped down through the tubing lo and out through the side ports of the upper cementing collar to cement the casing off above the enlarged cavity 2 as indicated at litt in Figure 2.
Second stage-When the first stage cementing job has been completed, the tubing lo and swab cupl l'" are lowered in the casing 3 to a point slightly abovethe lower or second stage cementing collar 9, as indicated in Figure 2:. The lowering of the tubing lo will break the retaining wires i4 and l5, freeing the basket l2 for expansion and vertical movement. Cement slurry is then pumped down through the tubing lo and out through the side ports ll' in the lower or second stage collar 9. As shown at i8 inVFigure 2, the cement slurry issuing from the ports l1 moves upwardly in the enlarged cavity 2,. pushing the basket l2-l3 upwardly ahead of the body of slurry to The lower basket 3 is not essential but prevents cement slurry from dropping down around the collars 6 and 7. Drilling fluid and any excess cement slurry in the enlarged cavity 2 is displaced upwardly through the ports l@ in the casing above the swab cup ll and will be washed out by circulation in the usual manner.
After the cement has set, the casing is cleaned out and a removable whipstock assembly 2li is run to bottom as shown in Figure 3. The assembly consists of a lower, indexing and locking member 35 (Fig. 8), an intermediate spacer member 48 in Fig. 3), the whipstoek body 23 (Fig 4) and an upper locking sleeve 5l (Fig. l0).
The removable whipstock assembly is a novel cornbination which not only provides the means for deflect-` ing the drilling bit (the bit is not shown), when drilling 3 the lateral drain holes 22, in the usual manner, but also provides together with the locating collar 7, means whereby any drain hole can be located quickly and conveniently at some later time.
As shown in Figure 4, the removable whipstock consists of a cylindrical steel body portion 23 having a central bore 24 which curves downwardly and outwardly, terminating in a side outlet window 25 through which a drilling bit can pass to cut a window 26 in the wall of the casing in the usual manner. Packing rings 27 are provided near the upper and lower ends of the whipstock body between the body and the interior wall of the casing to keep debris from becoming lodged between the whipstock and the casing. i The whipstock body 23 is supported by a spacer member 48 (Fig. 3). The lower end of the spacer member 48 is connected to the top of an indexing member 35, Fig. 8, which registers with the locking collar 7 as will be explained more fully.
The interior of the locking collar '7 is flush with the inside diameter of the casing. The slight bulge 28 on the outside of the collar to reinforce the wall of the collar opposite an internal vertical groove 29 (Figures 6, 7, 8 and 9) extends radially outward no further than the casing collars or the casing shoe 6. The groove 29 terminates at its lower end in an upwardly facing shoulder 31 which serves as a stop and seat for the whipstock.
In order to prevent the accumulation of gas pressure below the lower packing rings 27 a horizontal vent passage 32 (Fig. 4) above the lower packing 27 communicates with the internal bore of the tool joint 49. To minimize the danger of plugging the passage 32 with debris the upper end of passage 32 is divided into two branches 32a and a baffle tube 33 is threadedly secured within the bore of the tool joint 49 and extends a short distance below the tool joint. The wall of the spacer pipe 4B contains a port 34- through the wall thereof at a point somewhat above the lower end of the baie tube 33.
The indexing member of the whipstock assembly has a tubular body 35 (Fig. 8) having a longitudinal central bore 37. The body 35 makes a close running it in the bore of the casing 3. A vertical groove 38 is located in the outer surface of the body 35 near the lower end thereof. An indexing finger 39 is hingedly mounted in the groove 33 by means of a horizontal hinge pin 40 which extends through a hole 41 in the upper end of linger 39 and is secured to the body 35 by some suitable means such as the pin 42. A leaf spring 43 attached to the lower end of linger 39, as indicated by the bolts 44 bears against the inner face of the groove 33 as indicated at 45, urging the tinger 39 outwardly. The upper end of the body 35 is threaded as indicated at 46 to receive a tool joint 47.
The intermediate section ofthe whipstock assembly comprises a length of drill pipe having at its lower end a tool joint 47 (Figs. 3 and 8). The length of the drill pipe may be varied, as will be explained later. On the upper end of the drill pipe 48 is another tool joint 49 (Figs. 3 and 4).
The upper end of the body 23 is welded or otherwise secured to the lower end of a sleeve 51 which serves as a means for locking the top of the whipstock to the casing. The upper end of the locking sleeve S1 (Fig. l0) is provided with a series of vertical slots 52 extending downwardly for `several inches. The upper, outer portion of sleeve 11 is provihed with a series of horizontally disposed and downwardly directed serrations or teeth 53 adapted to engage the interior wall of the well casing 3. The top interior of the sleeve l is tapered downwardly and inwardly to form a frusto-conical face as indicated at S4. Below the tapered section the bore is recessed as indicated at 55 slightly beyond the depth of the threads Se which are formed on the lower interior bore of sleeve 51. A threaded hole 57 extends through 2t the wall of the sleeve 51 at the junction between the recess and the top of the threads S6 adapted to receive a shear pin or set screw (not shown) to prevent relative rotation between the members 51 and 59 while going into the well.
Threadedly connected to the upper end of body 51 is a tubular expander sleeve 59. The lower end of sleeve 59 is externally threaded as indicated at 60 for engagement with the internal threads 56 on body S1. Above the threads 60 the sleeve 59 is tapered upwardly and outwardly as indicated at 61 forming a frusto-conical surface which engages the inner frusta-conical face 54 on the toothed members 53. The uppermost portion of the expander sleeve S9 is tubular and may extend upwardly as far as may be desired.
The method of operation of the whipstock assembly is as follows:
After the well casing 3 with the locating collar 7 in place has been cemented and cleaned out, as previously described, the whipstock assembly is made up and run into the casing on the lower end of a string of drill pipe in the usual manner, by measuring it in until it is slightly above the locating collar, the position of which is known from previous measurements. The whipstock assembly is attached to the lower end of the drill pipe by any suitable detachable means, such as the well known bayonet lock 62 in the upper end of the expander sleeve 59 (Fig. l0). When the whipstock assembly has reached a point near the bottom of the well it is rotated and lowered slowly until the indexing member 35 is within the locating collar 7. Rotation of the assembly is continued until the linger 39 on the body 35 snaps into the groove 29 in the locking collar, thus preventing further rotation and allowing the weight of the entire assembly to be supported by the linger 39 resting on top of the shoulder 31 in the locating collar 7.
After the whipstock assembly has been seated and locked, as described above, the drill pipe (not shown) is rotated to the right, through the bayonet slot connection @l (Fig. 10). This causes relative rotation between the expander sleeve 59 and the locking sleeve 51 and causes the expander sleeve threads 6l) to be screwed downwardly into the threads 56 in the locking sleeve. The tapered shoulder 61 on the expander sleeve 59 moves downwardly into coneshaped face 54 on the locking sleeve 51 and forces the teeth 53 into engagement with the interior wall of the casing 3, thus locking the sleeve 51 and the whipstock assembly against axial movement within the casing 3.
The drill pipe is then removed from the well by first rotating it to the left to disengage the bayonet lock 62, after which the pipe can be withdrawn.
The device is now ready for the next well operation. This may be either the milling of a window through the casing or the drilling of a lateral drain hole.
After the lateral drain hole has been drilled, the whipu stock assembly is removed from the well. This is accomplished by running the drill pipe back into the hole, engaging the bayonet lock 62, rotating to the left to release the teeth 53 from engagement with the wall of the casing, turning to the right to re-engage the bayonet lock 62 and pulling the drill pipe and whipstock assembly out of the well. The pulling tool may be equipped with a spear (not shown) to engage the lower portion of the bore of the locking sleeve 51.
lf it is desired to drill additional drain holes, above the level of the first drain hole, a longer spacer pipe 4S is substituted for the original pipe 48. The whipstock assembly is then run into the well and locked in position as before. If it is desired to orient the upper drain hole with respect to the lower drain hole, it is only necessary to orient the whipstock body 23 with respect to the indexing member 35-39 when making up the entire assembly 2l. This is so because the indexing body 35--39, by yengagement with the locating collar 7, always locates the whipstock body 23 in either its original orientation or any desired change therefrom. It is customary to keep a record of the original orientation. Any desired number of drain holes can be drilled by the foregoing method. Any desired degree of orientation can be maintained.
If, at some subsequent time, it is desired to go back into one or more of the drain holes previously drilled, it is only necessary to make up the same assembly as was used in drilling the particular drain hole in question` By the same assembly is meant the same, or a similar, whipstock, indexing collar, locking sleeve and spacer pipe, using the same orientation of the respective parts as was used in drilling the original drain hole. When the locking finger 39 engages the groove 29 the entire assembly will be in the same oriented position as when the lateral drain hole was drilled originally. The length of the spacer pipe 48 will be chosen according to which drain hole it is desired to re-enter. After the whipstock assembly has been set and the drill pipe has been removed, drilling equipment or clean-out equipment can be run into the desired drain hole, the curved face 24 of the whipstock serving as a guide for the entering tools.
When a lateral drain hole is drilled in loose, unconsolidated sands such as are common in California and gulf coast oil fields, it is common practice to run a perforated liner into each of the lateral drain holes. Such liners must be flexible in order to bend around the entrance to the lateral drain hole. Several types of such exible, perforated liners are now in use. The particular design of such liners is not a part of the present invention except for means for sealing the space between the upper end of the liner and the bore of the drain hole. As shown in Fig. 3, the drain hole 22 begins at the window 25 and extends laterally through the thick wall of cement, which latter serves to form a permanent, durable cylindrical seat 64 for a packing sleeve 65 attached to the upper Vor inner end of a perforated liner 66. The innermost end of the liner 66 is provided with means for detachably connecting the 'liner to a liner setting tool, the J slot 67 being provided for this purpose. When the liner 66 and packing sleeve 65 are in place, as shown in Fig. 3, the packing sleeve 65 makes a snug t in the seat 64 and prevents sand from the drain hole 22 entering the main well bore 1 except through the perforated liner 66.
The liner 66 is run into or out of the well on tubing (not shown) having a liner setting tool (not shown) on the lower end thereof adapted to engage the J slot 67 on the end of the 'liner 66. The running and setting of liners is common practice and forms no part of the present invention.
While I have shown several embodiments of my invention, it is to be understood that my invention is not limited to these particular embodiments but is of the scope defined by the appended claims.
1. The method of drilling a series of lateral drain holes in a well comprising drilling a substantially vertical main bore hole to the total depth required, running casing to the bottom of the well, said casing being provided with -a whipstock indexing member, cementing said casing in the Well, removing any excess cement from the interior of the casing, running a whipstock assembly Acomprising an indexing member, a spacer member, a whipstock and a locking member, locking said whipstock assembly in position, noting the relative orientation of the whipstock to the indexing member, as assembled, drilling a lateral drain hole into the oil producing formation, said drilling operation being guided by said whipstock, removing the whipstock assembly from the well, replacing the spacer member with another spacer member having a greater length than said first spacer member, noting the relative orientation of the whipstock with respect to the indexing member, running the altered whipstock assembly into the well, locking the whipstock assembly to the indexing member in the well casing, drilling a second lateral drain hole at a higher elevation in the well than said rst drain hole and removing the whipstock assembly from the well.
2. Apparatus for drilling lateral drain holes in Wells comprising, a whipstock assembly a well casing having a whipstock locating collar connecting adjacent sections of said casing adjacent the lower end thereof, said locating collar having whipstocloorienting means in fixed position therein and adapted to prevent relative rotation between said collar and said whipstock assembly comprising a vertical groove having an upwardly facing shoulder on the lower end thereof means on the lower end of said whipstock assembly for engaging the orienting and rota tion preventing means and extending upwardly therefrom to provide a spacer member having a spring-actuated nger engageable with said groove and shoulder, a Whipstock secured to the upper end of said spacer member, and whipstock-locking means on the upper end of said whipstock to lock said whipstock against axial movement in a well casing.
3. Apparatus for drilling lateral drain holes in wells comprising, a whipstock assembly, a well casing having a whipstock locating collar adjacent the lower end thereof, said locating collar having whipstock-orienting means in fixed position therein and adapted to prevent relative rotation between said collar and said whipstock assembly, comprising a vertical groove having an upwardly facing shoulder `on the lower end thereof, means on the lower end of said whipstock assembly for engaging the orienting and rotation preventing means and extending upwardly therefrom to provide a spacer member having a springactuated finger engageable with said groove and shoulder, a whipstock secured to the upper end of said spacer member, and whipstock-locking means on the upper end of said whipstock to lock said whipstock against axial movement in a well casing and comprising a locking sleeve on the upper end of said whipstock assembly, said locking sleeve having internal threads near the upper end thereof and having expandable wedge members on the exterior thereof and an expander sleeve threadedly -connected to said locking sleeve for expanding said wedges when said expander sleeve is threaded into said locking sleeve.
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