US2889137A - Apparatus for drilling laterals from well shafts - Google Patents

Description

R. K. WALKER June 2, 1959 APPARATUS FOR DRILLING LATERALS FROM WELL SHAFTS Filed Feb. 13. 1958 2 Sheets-Sheet 1 June 2, 1959 R. K. WALKER APPARATUS FOR DRILLING LATERALS FROM WELL SHAFTS Filed Feb. 13, 1958 2 Sheets-Sheet 2 Un ees Pae M Patented June 2, 1959 APPARATUS FOR DRILLING LA'IERALS FRo WELL SHAFTS Robert K. Walker, Tulsa, Okla. Application February 13,195 Serial Na. 714,997 9 Claims. (Cl. 255-20 This invention relates to new and useful iinproiiemerits in well dr-illing apparatus, and has particular ref erence to apparatus for drilling lateral here's frem well shafts.

It is well known that in many types of wells, such. as oil, water and gas wells, a well often ceasesto new be cause the fluid is trapped in solid or semi-solid sand formations, and the fluid-bearing sand immediately surrounding the well shaft has become drained, se that from more distant portions of the formation cannot reaeh the shaft, or reaches it at such a low rate as to render Operation of the well economically unfeasibl. It has long been known that many wells could be rejuvenated and caused to flow freely again if lateral or radial drill ings could be made from the main shaft into dist-ant por tions of the fluid-bearing formations, so that fluid could flow freely to the main shaft and flow or be pumped to the surface.

However, all previous apparatus proposed for this pur pose, within my knowledge, has been so involved, expensive or otherwise impractical that they have not ceme into general use, it often being simpler and cheaper to drill new wellsfrom the surface to untapped formations even though said formations might be quiteclose to existbig old wells.

The primary objects of the present invention are, therefore, the provision of an apparatus capable of drilling laterals from a well shaft in a practical and efficient manner, to operate at any depth below the ground surface, and to drill laterals of any desiredlength and in any desired horizontal direction from the shaft. .Generally, these objects are accomplished by means including a housing adapted to be lowered into a well shaft, power means carried by said housing and operable to rotate a drill rod and to extend it simultaneously horizontally outwardly from said housing, said drill rod being formed in short sections, and means carried by said housing and operable to add new sections to said drill rod as required, said sections being stored in and fed from a magazine extending vertically in the well shaft.

Other objects are simplicity and economy of construction, efliciency and dependability of operation, and adaptability for use in a wide variety of applications.

With these objects in view, as well as other objects which will appear in the course of the specification, reference will be had to the drawing, wherein:

Fig. 1 is a fragmentary vertical sectional view, with parts left in elevation and partially broken away, of a lateral drilling apparatus embodying the present invention, shown in operative relationship to a well shaft,

Fig. 2 is a sectional view taken on line 22 of Fig. 1, and

Figs. 3, 4 and 5 are fragmentary sectional views taken respectively on lines 3--3, 4-4, and 55 of Fig. 1.

Like reference numerals apply to similar parts throughout the several views, and the numeral 2 applies to a well shaft, lined by the usual tubular casing 4, from which it is desired to drill a lateral. The apparatus forming the subject matter of the present invention includes a hollow housing 6 adapted to be lowered into the casing. Said casing is supported by a rod 8 disposed axially in the casing and rigidly secured at its lower end to top wall 10 of housing 6 by nuts 12. It will be understood that said rod extends to the ground surface and is there engaged by any suitable apparatus, notshown, for supporting the housing, and that the length of said rod bye-increased by adding extension. sections thereto as e quired, in order to support the housing at any desired depth. At one side thereof, housing ,6 also includes pocket 14 defined by vertical side walls 16 and a door 18 closing the lower side thereof, said door being hinged at 20 to a side wall 22 of housing 6 and being biased upwardly toward a closed position by springs 24 carried by said hinge. Said door opens downwardly fromhous ing 6, for a purpose which will appear below.

Pocket 14 is elongated, extending generally radially to the extended axis of support rod 8, being open at the top and at its outer end, and opening at its inner end into the main body portion 26 of housing 6, through side wall 22 thereof. Said poeket is of sufiicient length and transverse width to support therein one of drill rod sections 28. Each of said drill rod sections is cylindrical in form and is tubular, having an axial passage 30 therethrough. It is provided at one end with a reduced, ex ternally threaded extension 32, at its opposite end with a corresponding internally threaded socket 34, and at a point intermediate its ends with side inlets 36 to axial passage 30. Drill rod sections 28 are adapted to be threaded together in a string to form a continuous rod as best shown in Fig. 1, in a manner to be described. The outermost section 28 is adapted to be connected with a drill bit ssor the same diameter as the rod sections, and having a threaded extension 39 suitable for engagement in the socket 34 of the associated drill rod section; The extension 32 of each rod section, and extension 39 of bit 38, is provided with a diametrical slot 40, for a purpose which will presently appear.

Rig-idly attached to housing 6, and extending upwardly therefrom, is a tubular guide 42 ofrecta ngular horizontal contour. Said guide is interconnected at its lower end with pocket 14, and is provided at itslower end with an inturned lip 44 (see Fig. 1). It will be understood" that this guide extends also to the ground surface, and may be provided with sectional extensions for this purpose. Carried for vertical sliding movement in' guide 42 is a tubular magazine 46, alsoof rectangular contour, adapted to support a series of drill rod sections 28 in stacked relation therein. The rod sections are stacked with their axes horizontal, andwith the threaded extensions thereof at their inner ends, or extending toward the axis of support rod 8, being disposed adjacent the" vertical wall 48 of the magazine.

The lower end of the magazine is engaged by lip of guide 42 to prevent said magazine from entering pocket 14 of the housing. The magazine is also pro vide'd with an internal lip 50 at the bottom of wall 48 thereof, which lip engages the extension 32 of thelo wermost drill rod section 28 in the magazine to prevent said rod section from falling into pocket 14. Moreover, the distance between magazine wall 48 and the opposite wall 52 of the magazine corresponds closely to the length of rod section 28, so that they must engagelip 50'. However, wall 52 is provided at its lower end with an out ward offset 54 which permits the lowermost rod section 28 to be moved axially outwardly to a point where it isv freed from lip 50, and will fall into housing pocket 14 by gravity. Magazine 46 has a cable 56 attached to the upper end thereof whereby it may be elevated to the surface of the ground to be refilled with additional drill rod sections when necessary.

The drill rod sections 28 are dislodged successively from lip 50 of the magazine by a pusher member carried for horizontal sliding movement in a socket mem: ber 60 formed integrally with the wall of magazine guide 42 directly adjacent magazine wall 48, just above the lower end thereof. Said socket opens inwardly toward the magazine, and the axis thereof is horizontal and parallel to the axes of drill rod sections 28 in the magazine and in housing pocket 14. Aflixed to pusher 58 is an operating rod 62 which extends horizontally and slidably through the base of socket 60, into housing body portion 26. A compression spring 64 coiled about said rod bears at one end against socket 60-, and at its opposite end against a collar 66 affixed on said rod, whereby pusher 58 is urged resiliently away from the magazine. When said pusher is moved toward the magazine, against the pressure of spring 64, it enters the magazine through a hole 68 formed in the wall 48 thereof, whereby to dislodge the lowermost drill rod section carried therein from lip 50, as will be described, to permit said drill rod section to drop into housing pocket 14.

Carried in housing portion 26, directly in axial alignment with the open inner end of housing pocket 14, is a cylindrical and tubular plunger 70, said plunger being journalled in the upright leg 72 of a heavy frame member 74 affixed to bottom wall 76 of the housing as by rivets 78. Said plunger is parallel to pusher operating rod 62, and is closed at the end thereof adjacent pocket 14, being provided externally at this end with a diametric rib 80 operable to engage in the slot 40 of the drill rod section 28 resting in pocket 14, whereby to rotate said drill rod section about its axis when said plunger is rotated as will be described.

A shaft 82 is disposed horizontally and coaxially with plunger 70, extending into said plunger and being journalled externally of said plunger in an upright leg 84 of frame 74. Said plunger is free to slide longitudinally on the shaft, but is prevented from rotating relative thereto by a key 86. said shaft is prevented from moving longitudinally by a bevel gear 88 and a collar 90 affixed thereon respectively at opposite sides of frame leg 84. Surrounding plunger 70, and rotatable thereon, is a collar 92, said collar being retained between a flange 94 formed integrally with the plunger and a lock ring 96 threaded on said plunger. Aflixed to collar 92 is an upright, radially extending finger 98, the upper end of which is formed to present a bifurcated head 100 which straddles operating rod 62 of pusher 58, and is slidable there-along. Affixed also to collar 92 are a pair of oppositely extending radial bars 102, which are utilized in reciprocating plunger 70, as will presently appear.

Bevel gear 88 of shaft 82 is meshed with a bevel gear 104 afiixed on a vertical drive shaft 106. Said drive shaft is journalled at its lower end in the upper end of an upright leg 108 of frame 74, and extends upwardly, being journalled in a bearing 110 afiixed to top wall of housing 6. Said drive shaft extends to the ground surface and is rotated about its axis by any suitable power device, not shown, at ground level. It will be understood that said drive shaft may be provided with extension sections in order to position housing 6 at any desired depth. A collar 114 afiixed on the drive shaft and abutting the lower face of bearing 110 prevents said drive shaft from moving upwardly in the housing, and provides that, where desired, the drive shaft may be used to support the housing instead of rod 8.

Affixed on drive shaft 106 within housing 6, and just below gear 104, is another bevel gear 116 which is meshed with a bevel gear 118 which is in turn aflixed to a horizontal shaft 120, said shaft being journalled in leg 108 of frame 74, and extending transversely to plunger 70. Aflixed to the opposite ends of shaft 120, and disposed respectively at opposite sides of plunger 70, are a pair of planar discs 122 to each of which is affixed an outwardly extending rod 124, said rods being coaxial with each other, and parallel to but spaced eccentrically from shaft 120. Each of rods 124 is interconnecte'd by means of a link 126 with the bar 102 of collar 92 at the corresponding side of plunger 70, as best shown in Fig. 2. Each of said links is pivoted to a rod 124,.

and is longitudinally slidable with respect to bar 102 by 4 virtue of the extension of said bar through a slot 128 formed longitudinally in said link. Said link is retained on bar 102 between a pair of nuts 130 threaded on said bar. A helical compression spring 132 is coiled about each of links 126, bearing at one end against bar 102, and at its opposite end against a pin 134 inserted trans- Yersely through said link, whereby to extend the effective length of said link resiliently.

The operation of the device is substantially as follows: The housing 6 is first lowered into the well by means of support rod 8, or, in cases where said support rod is not used, by means of drive shaft 106. Support by means of rod 8 is preferable, since it may be utilized to turn the housing to direct housing pocket 14 in any angular direction from the shaft, in order to direct the lateral to be drilled in the desired direction. Extension sections are of course added to rod 8, tubular guide 42 and drive shaft 106 as required, in order that the housing may be positioned at the desired depth. A magazine 46 filled with drill rod sections 28, supported therein by magazine lip 50, is lowered through guide 42 by means of cable 56 until the magazine is arrested and supported by housing lip: 44. Although the lowermost drill rod section 28 is supported in the magazine by lip 50 only at one end portion of said drill rod section, said drill rod section is prevented from tilting and falling into pocket 14 by the weight of the other drill rod sections resting thereon. The support occurs in the same manner that a stack or pile of ordinary boxes may be supported by a ledge engaging only a portion of the bottom surface of the lowermost box. Tilting of the bottom member of such a stack, which must occur if it is to be disengaged from the ledge, cannot occur without a slight elevation of the whole stack, and this cannot occur if the weight of the stack is disproportionately large as compared to the weight of a single member of the stack. The drill bit 38 may be inserted at the bottom of the magazine, or if the bit has a toothed head 136 too large to fit into the magazine, the bit may be inserted into housing pocket 14 before the housing is lowered into the well, with head 136 disposed just outside of the pocket.

Drive shaft 106 is then set in operation by a suitable power means, not shown, at the ground surface. The drive shaft functions through bevel gears 104 and 88, shaft 82 and key 86 to rotate plunger 70 about its axis, and through gears 116 and 118, shaft 120, rods 124, links 126 and bars 102 to reciprocate said plunger longitudinally through housing socket 14. Assuming first that said pocket is empty, the plunger will advance through said pocket till finger 98100 carried by said plunger engages collar 66 of pusher operating rod 62, and forces pusher member 58 to enter the magazine through hole 68 thereof to dislodge drill bit 38 from lip 50, allowing said bit to fall and rest on the top of the plunger. When the plunger is next withdrawn from the pocket, the bit will fall into the pocket to rest on door 18, the door springs 24 being suficiently strong to support said bit, or any drill rod section. As the plunger next advances into pocket 14, rib '80 thereof engages extension 39 of the drill bit, causing rotation of said bit as the toothed head 136 thereof is forced outwardly, whereby to drill a hole 138 in casing 4 and a hole 140 in the surrounding ground formation. It will be seen that as the bit drops into pocket 14, it is gripped resiliently between a pair of leaf springs 142 (see Figs. 2 and 5) affixed respectively to the side walls 16 of said pocket. Said springs serve as a brake on the rotation of the bit to imsure that rib 80 of the plunger will turn relative to the bit and engage securely in slot 40. Due to the step-up ratio of gears 104--88, and the step-down ratio of gears 116118, the

plunger makes several revolutions during each reciprocation thereofj Since a maximum of one-half revolution of the plunger is required for rib 80 thereof to find" and enter the slot 40 of the drill bit, the drill bit will still be turned several times after the slot thereof is engaged by the plunger rib, and during the same stroke of the plunger.

The bit is pressed outwardly as it is rotated, by links 126, which are of course resiliently yieldable by virtue of springs 132. If the bit encounters solid rock or other obstructions relatively difficult to penetrate, springs 13?. will yield and the bit will advance to some lesser degree. In this manner a large number of reciprocations of the plunger may be utilized to advance the bit sufficiently that it is expelled substantially completely from pocket 14. When it actually is substantially completely expelled, plunger 74 will be advanced far enough into pocket 14 that finger 98-1dfi carried thereby will actuate pusher member 58 to dislodge the next drill rod section from magazine lip 56 and allow it to drop to be supported on the upper surface of the plunger, and thence to drop into pocket 14 directly in alignment with the plunger when said plunger is next retracted. In no case will a drill rod section be dislodged from the magazine by pusher 58 until the next preceding section has been expelled from the pocket 14 to clear said pocket for the reception of the next section. Each successive section is threaded to the next preceding section by the rotation of plunger 70, and the resulting composite drill rod is rotated and advanced by the plunger.

In this manner the lateral hole 140 in the surrounding earth formation may be extended to any desired distance. If necessary, the magazine may be elevated to the ground surface and reloaded with additional drill rod sections. The composite drill rod formed by sections 28 is left in the hole 140, and acts as a perforated pipe through which oil, gas or the like released from the formation tapped by hole 140 may flow back into the well shaft, from whence it will flow or can be pumped to the ground surface. By turning housing 6 or moving it to different elevations, laterals 140 may be drilled at any angle from the shaft, and at any elevation. When the housing is lifted from the well, any portion of the drill rod still extending into pocket 14 thereof does not lock the housing in the shaft, but merely deflects door 18 downwardly against the pressure of springs 24, thereby freeing the housing from the drill rod.

While I have shown and described a specific embodiment of my invention, it will be readily apparent that many minor changes of structure and operation could be made without departing from the spirit of the invention as defined by the scope of the appended claims.

What I claim as new and desire to protect by Letters Patent is:

1. An apparatus for drilling laterals from well shafts comprising a housing adapted to be lowered into a well shaft, a magazine carried by said housing, a plurality of rotary drill rod sections carried on said magazine and disposed in stacked relation therein with their axes substantially horizontal, said magazine being operable to deposit the lowermost drill rod section therein in a pocket of said housing, said pocket opening laterally of said housing, said drill rod sections having cooperating connector portions whereby they are adapted to be joined together in coaxial relation to form a drill rod by relative rotation thereof about their axes, means including a plunger carried by said housing for horizontal reciprocal movement through said housing pocket, whereby said drill rod sections are successively ejected from said housing in coaxial relation, and power means operable to reciprocate said plunger, said power means also being operable to rotate said plunger simultaneously about its axis of reciprocation, said plunger having means carried thereby and operable to engage and rotate each of said drill rod sections as it is ejected from said housing, whereby said drill rod section is joined to the section previously ejected, and whereby the resulting composite drill rod is rotated to drill a hole laterally from said well shaft.

2. A drilling apparatus as recited in claim 1 wherein each of said drill rod sections is axially tubular and has side openings to the interior thereof, whereby the composite drill rod formed by said sections constitutes a perforated pipe operable to drain liquid from the lateral drilled thereby to the main well shaft.

3. A drilling apparatus as recited in claim 1 wherein the reciprocating and rotating means for said plunger includes a common vertical power shaft extending from said housing to the surface of the ground, whereby said shaft may be turned by any suitable prime mover, said shaft being secured against withdrawal from said housing whereby said shaft may serve as a supporting means for said housing.

4. A drilling apparatus as recited in claim 1 with the addition of a rigid support member atfixed to said housing and extending to the surface of the ground, whereby said housing may be rotated about its vertical axis to permit drilling of said lateral hole in any direction desired from the well shaft.

5. A drilling apparatus as recited in claim 1 wherein said magazine is separable from said housing, and with the addition of means whereby said magazine may be elevated to the ground surface independently of said housing, for the purpose of refilling with additional drill rod sections.

6. A drilling apparatus as recited in claim 1 wherein said plunger reciprocating means is resiliently yieldable so that any necessary number of reciprocations of said plunger may be utilized to eject each drill rod section from the housing pocket.

7. A drilling apparatus as recited in claim 1 wherein said plunger reciprocating means is resiliently yieldable so that any necessary number of reciprocations of said plunger may be utilized to eject each drill rod section from the housing pocket, and wherein said magazine is provided at its lower end with a ledge normally supporting the lowermost drill section therein against entry into said housing pocket, and with the addition of a pusher member connected to said plunger reciprocating means and operable to dislodge lowermost drill rod section in said magazine from said magazine ledge to deposit it in said housing pocket, said pusher member being inoperable until the preceding drill section has been substantially completely ejected from said housing pocket.

8. A drilling apparatus as recited in claim 1 wherein the bottom wall of said housing pocket constitutes a pivoted door which opens downwardly from the bottom of said pocket, whereby said housing may be elevated out of the well shaft at any time even if the composite drill rod extends into said housing pocket, and with the addition of resilient means urging said door upwardly to its normal position.

9. A drilling apparatus as recited in claim 1 which the bottom wall of said housing pocket constitutes a pivoted door which opens downwardly from the bottom of said pocket, whereby said housing may be elevated out of the well shaft at any time even if the composite drill rod extends into said housing pocket, and with the addition of resilient means urging said door upwardly to its normal position, and wherein said magazine is provided at its lower end with a ledge normally supporting the lowermost drill section therein against entry into said housing pocket, and with the addition of a pusher member connected to said plunger reciprocating means and operable to dislodge lowermost drill rod section in said magazine from said magazine ledge to deposit it in said housing pocket, said pusher member being inoperable until the preceding drill section has been substantially completely ejected from said housing pocket.

References Cited in the file of this patent UNITED STATES PATENTS 2,147,214 Perebaskine et a1 Feb. 14, 1939 2,383,496 Nebolsine Aug. 28, 1945 2,810,547 Fehlmann Oct. 22, 1957

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