US2539047A - Side drill - Google Patents

Description

Jan. 23, 1951 A. ARUTUNOFF SIDE DRILL Filed June Illia. .l2

Patented Jan. 23, 1951 UNITED STATES PATENT OFFICE SIDE DRILL Armais Arutunof, Bartlesville, Okla.

Application June 17, 1946, Serial No. 677,196

(Cl. Z55- 1.6)

12 Claims. 1 The present invention relates in general to drilling apparatus and more particularly to side drills for oil wells or bore holes of similar character.

It often is desirable to extend an existing well by drilling auxiliary holes at an angle from the vertical bore hole either for the purpose of tapping formations which do not communicate with the original bore hole, or for some other purpose. The usual way of producing such holes is to lire projectiles into the side wall from a gun lowered in the well. However, the depth of penetration which may be obtained by this method naturally depends upon the hardness of the material to be pierced, and as a practical matter has proved to be much too limited to be useful where the formation is hard or where the cement behind the well casing is of considerable thickness.

It is the fundamental object of my invention therefore to provide apparatus by means of which a deeper penetration may be obtained.

Another object is to provide a side drill which may be advanced into the side wall to any desired depth and then halted, the extent of the advance being registered at all times at the surface of the well.

Another object is to provide a side drill adapted kto be lowered into a bore hole, together with novel apparatus for locking the drill unit tightly in the bore hole when it is at the level to be a drilled. Another object is to provide apparatus in the side drill unit to assist in orientation of the bit.

Another object is to provide an arrangement for carrying uid to the bit of the drill unit at all times during its penetration into the side wall.

Another object is to provide novel facilities for catching and collecting the cuttings returned to the main or vertical bore hole by the drilling apparatus.

Other objects and features of my invention will appear from the following description.

In the accompanying drawings which form a part of the instant specification and are to be read in conjunction therewith and in which like reference numerals are employed to indicate like parts of the various views,

, Fig. 1 is a View showing the upper portion of my side drill in longitudinal cross section.

Fig. la is a view showing the lower portion of my side drill in longitudinal cross section.

Fig. 2 is a sectional view taken along the line 2--2 of Fig. 1a,

Fig. 3 is an enlarged cross section of the bit,

Fig. 4 is a side elevation of a modified form of my drill, and

Fig. 5 is a view showing the modified form of drill from the bottom.

Referring more particularly to the'drawings, the housing for my side drill is made up in two units. The upper unit comprises a cylindrical shell II having rigidly affixed thereto a cap I2 and a bottom piece I3; the lower unit comprises a somewhat shorter cylindrical shell I4 which in like fashion has immovably secured to it a flanged cap I5 and a bottom piece I6. The flanged cap I5 of the lower unit is fastened to the bottom piece I3 of the upper unit by means of screws I8, joining the two units to form a single rigid structure.

In the upper half of this structure is an electrical motor I9 having a rather elongated cylindrical casing. The motor casing is adapted to move axially of its surrounding shell but it cannot rotate therein due to the presence of a pair of longitudinal ribs or splines 20 on the inside of the shell which cooperate with a slotted collar 2I on the outside of the motor casing.

Above the motor casing and securely fastened thereto by screws 23 is another generally cylindrical casing 24. This has a flattened side wall 25 at its top, in which side wall the shaft 26 of a reel 2l is journaled. A string or light cable wound on the reel has its free end secured to a hook in the cap I2 so that it will cause the reel to turn as the casing 24 moves downwardly nside shell II. Through suitable reduction gearing this turns the shaft of a rheostat 28.

The wiring from the rheostat and motor I9, as well as that from a Selsyn motor equipped gyroscope 29, extends upwardly into a tube 30 and thence through the steel clad cable 3I to the surface. The tube 30 is rigidly aixed to the cable at one end and to the casing 24 at its other end, and accordingly moves up and down with the latter. A suitable packing gland is provided in cap I2 to prevent fluid from entering the top of the side drill unit around tube 30.

Insulating oil lls the chamber 32 and extends downwardly through the central opening in a disk-like separator 33 and thence through tube 34 into the motor, which runs in oil. Below the separator 33 is a piston 35 and a spring 36. The under side of the piston communicates with the space outside casing 24 through two apertures 31, while the space 38 above the piston communicates with the chamber 32 through a small breather hole 39 in separator 33. Accordingly the piston will move up or down to compensate for differences in pressure which may exist between chamber 32 and the region outside the casing.

A tube 40 is rigidly affixed to the bottom of the motor casing I9 so that it extends downwardly into the vertical sleeve 4| secured to the bottom piece I3. A stuffing box 42 at the upper end of sleeve 4I permits tube 40 to slide in and out of the sleeve but seals the junction against the passage of fluid.

In the lower portion of the side drill structure is a rigid tube 44 curved as shown and communicating at its lower end with an opening 45 in the wall of shell I4. This serves as a guide for a longitudinally movable fiexible sleeve or casing 46, the upper end of which is securely fastened to tube 40. Below tube 40 and encircling the flexible casing in the region within sleeve 4I a. coiled spring 41. A flexible drive shaft 48 extends upwardly inside the exible casing and at a point inside tube 46 it is rigidly attached to the lower end of the motor shaft 49. Thus the sleeve 4I and the tube 44 form rigid tubular guide means for the flexible shaft 48 and the exible sheath or casing 46.

Referring to Fig. 3 it will be noted that the hollow shank I of a bit member 52 is secured to the end of the drive shaft 48. This shank is journaled in a thrust member 53 which is fastened tightly to the end of the flexible casing 46. A pair of thrust Washers 54 are provided between the bit and the bearing surface of the thrust member.

Attention is directed to the orifice 55 in the bit and to the aperture 56 in the hollow shank thereof; uid entering the tube 40 through the opening 51, as will be described presently, may move downwardly through this tube in the space surrounding the motor shaft, then downwardly through the fiexible casing 46 in the space surrounding the flexible shaft contained therein and, after passing through aperture 56 and the shank of the bit, it will be expelled through orifice 55.

@hoelwgdgemis pivoted at 60 on the bottom piece I6 of the side drill. This shoe has a series of serrations 6I along one arcuate edge thereof, with respect to which arcuate edge the pivot 66 is disposed eccentrically, as shown. Connected to the shoe is a piston 62 adapted to move up and down in the cylinder 63 under-control of fluid admitted to the cylinder through a small pipe 64. The piston rod 65 extends downwardly through a suitable packing gland 66 and is bifurcated at its lower end to straddle shoe 59. By means of a pin 61 passing through a slot 68 in the shoe, movement of the piston will cause the shoe to rotate about its pivot.

Below the motor but inside the casing I9 is a pump (not shown) which is driven by the motor. The pump intake comprises a small flexible tube extending downwardly in a loosely coiled helix and terminating in the chamber 1I. Amghgck .valve indicated schematically atlgmpyermits fluid to enter this chamber from outside the shell I4.` Fluid is expelled from the pump into chamber 13 through the outlet 14, and from chamber 13 it may flow either through aperture 51 toward the discharge orifice in the bit as hereinbefore described or it may ow through the small pipe 64 into the hydraulic cylinder 63.

In operation, my side drill functions as follows: The unit is lowered into the bore hole to the desired depth by means of the cable 3|. If the well is dry at the point to be drilled. liquid is in- 4 troduced into the bore hole until the drill unit is entirely submerged. Orientation of the unit may be observed at the surface by means of a Selsyn motor connected to the Selsyn motor of gyroscope 29 in conventional fashion.

When the side drill is at the desired level and is properly oriented, the motor I9 is started by means of a switch at the surface. Thereupon, the pump, drawing fluid into the lower chamber 1I through valve 12 and thence upwardly through tube 16, discharges it into the upper chamber 13. Part of the fluid passes from the upper chamber through the opening 51 and out orifice 55 as hereinbefore explained; the orifice is small in comparison with the capacity of the pump however, and consequently pressure is built up in chamber 13 which forces fluid through tube 64 and into cylinder 63. This pressure acting on piston 62 draws up the shoe 59 so that its serrated edge 6I rmly engages one wall of the well casing 16.

Cable 3| now is paid out slowly with the motor I9 still running. As the drill unit moves downwardly, shoe 59 causes the lower end thereof to move laterally and become wedged in the casing of the well in such a way as to press the opening 45 firmly against the side wall of the bore hole (see Fig. 1a). If the cable 3| now is paid out still more, the motor and the auxiliary casing 24 with the instruments contained therein will move downwardly due to their own weight, driving tube 46 and the flexible sleeve or casing 46 downwardly before them. The bearing 53 at the end of the latter casing accordingly transmits a thrust to the` rotating bit, causing it to advance through 4'the vcasing 16Mand intovthe side wall v'along the path indicated by'dotted lines in Fig.

1a. Spring 41 serves as a support to prevent the upper end of the flexible sleeve 46 from buckling under the compressive force acting thereon.

As it advances, the movement of casing 24 relative to the outer shell of the side drill unit causes reel 21 to turn and this progressively changes the setting of rheostat 28. The resultant change in resistance controls a milliammeter or other electrical instrument at the surface, enabling the operator to determine just how far the bit has advanced so that he may stop drilling at any desired depth. The maximum depth of penetration is determined by the distance which tube 40 may travel before it is completely telescoped within sleeve 4 I. This obviously may be increased by increasing the length of the tube, the sleeve and the associated parts; if the distance between motor casing I9 and bottom piece I3 were made 30 feet, for instance, the bit could be advanced approximately 15 feet into the side wall. For a penetration of 15 feet, tube 3D naturally would also have to be 15 feet long.

Throughout the advance of the bit the fluid expelled through the orifice therein assists in the drilling operation and flushes the cuttings back into the well bore. A sealing ring 11 pro vided in a suitable annular groove in bottom piece I6 engages the casing 16 of the well bore to better localize the circulating fiuid, whereby the cuttings returned to the well bore tend to be drawn into chamber 1I through the intake valve 12 and to settle in the bottom thereof around the hydraulic cylinder.

When employing my side drill in an uncased hole the same method of operation as described above is followed. In place of the shoe 59 however a spade 59' preferably is substituted, as shown in Figs. 4 and 5. Thisserves the same purpose as the shoe and functions in the same general way, but it has a broad, somewhat sharpened edge 6I' which is better adapted than the shoe to dig into the side wall in order to wedge the bottom of the side drill unit in the borehole. From the foregoing it will be seen that this invention is one well adapted to attain all of the ends and objects hereinbefore set forth together with other advantages which are obvious and which are inherent to the apparatus.

It will be understood that certain features and subcombinations of utility may be employed without reference to other features and subcombinations. This is contemplated by and is within the scope of the claims.

Inasmuch as many possible embodiments may be made of the invention without departing from the scope thereof, it is to be understood thatl all matter herein set forth or shown in the accompanying drawings is to be interpreted as illustrative and not in a limiting sense.

Having thus described my invention, I claim: l. In a side drill for a well bore, a casing adapted to be lowered into the well bore, a rigid `guide tube in said casing having o-ne end opening toward the side wall to be drilled, a flexible sleeve having one end within said tube and the other end extending out of the tube into the body of said casing, a flexible shaft within said sleeve, a bearing rigidly affixed to said one end of said sleeve, a bit supported by said bearing and attached to the end of said shaft, means to apply a force to said other end of said sleeve in such a direction as to cause said bearing to transmit a thrust to said bit to advance same toward said side wall, means to support other end of said sleeve comprising a spring coiled about said sleeve and a rigid tube encircling said spring, and mechanism to rotate said shaft within said sleeve and hence rotate said bit as it advances.

2. In a side drill for a Well bore, a casing adapted to be lowered into the well bore, a rigid guide tube in said casing having one end opening toward the side Wall to be drilled, a flexible sleeve within said tube and a flexible shaft within said sleeve, a bearing rigidly affixed to the end of said sleeve, a bit supported by said bearing and attached to the end of said shaft, an orifice in said bit communicating with the interior of said sleeve, apparatus to advance said sleeve and shaft while rotating said shaft in said sleeve,

thereby to drill the side wall, a sediment chamber in said casing having an inlet positioned below that end of said rigid guide tube which opens toward the side wall,` and pump means for drawing fluid into said chamber through said inlet and driving it through said flexible sleeve to expel it through the orifice in said bit.

3. In a side drill as claimed in claim 2, a sealing ring encircling said casing at a point below said inlet and engaging the side wall of the well bore to prevent drill cuttings from descending therebelow.

4. In a side drill, a casing adapted to be lowered into the well bore, a rigid curved guide tube in said casing having one end opening toward the side wall to be drilled, a flexible shaft in said casing having at one end a bit directed toward the side wall, mechanism to rotate said flexible shaft and to advance it with respect to said rigid tube thereby to drill said side wall, a rheostat, mechanism to progressively change the resistance of said rheostat as the flexible shaft advances with respect to said guide tube, and electrical conductors leading from said rheostat for connection to a device at the surface controlled on a cable to enable same to be lowered into abore hole, a casing enclosing said motor housing and movable relative to said housing and said cable in a direction axial of the bore hole, a rigid curved guide tube in said casing having one end opening toward the side wall of the well bore, a flexible shaft in said guide tube having one end connected to the motor shaft for rotation thereby and the other end connected to a bit directed toward the side wall of the bore hole, a pump connected to said motor, a hydraulic piston operated by said pump, and a member on said casing connected to said piston and operated by said piston to lock said casing in the bore hole at a h ereafter vadvanc'e's'f'"said flexible shaft through said curved tube to drill said side wall.

6. In combination, a vertically elongated casing adapted to be lowered into a well bore, a partition in said casing dividing the same into upper and lower compartments, a motor and pump rigidly connected together to form an integral unit, means supporting said unit in one of said compartments, said pump having its intake connected to one of said compartments and its exhaust connected to the other of said compartments, whereby they form suction and pressure compartments respectively, a port in the wall of the suction compartment for admitting fluid thereinto from the well bore, and a hydraulic ram connected to said pressure compartment and operated by fluid under pressure therefrom, and a device actuated by the ram for engaging the side wall of the well bore to immobilize said casing in the Well.

7. In a side drill, a vertically elongated casing adapted to be lowered into a well bore, a partition in said casing dividing same into upper and lower compartments, a motor and pump rigidly connected together to form an integral unit, means supporting said unit in one of said compartments for movement axially of the casing, a bit connected to the motor shaft by a flexible shaft, guide means for the flexible shaft to cause same to issue from the side of the casing and advance the bit laterally as said unit moves axially in the casing, said pump having its intake connected to one of said compartments and its exhaust connected to the other compartment whereby they form suction and pressure compartments respectively, and a port in the wall of the suction compartment for admitting fluid thereto from the well bore, said port disposed below the level at which said flexible shaft issues from the casing.

8. A side drill as in claim 7 including a flexible sleeve around the flexible shaft, said sleeve having one end adjacent the bit and its other end communicating with said pressure compartment whereby the fluid pumped into the latter compartment flows through said sleeve to said bit.

9. A side drill as in claim 7 including an annular dam around the casing below the level of said port bridging the space between the casing 'and the inner wall of the well bore.

10. In a side drill as inclaim 7 wherein said unit is in the upper compartment, a support connected to said unit and extending upwardly through an aperture in the top of said casing to the surface to carry the weight of said unit, said casing being vsupported and carried by said unit during its descent into a well bore, and apparatus to lock said casing in the well bore at a particular level whereby the continued descent of said unit thereafter advances said flexible shaft rand bit laterally.

11. In a side drill, a vertically elongated casing adapted to be lowered into a well bore, partition means dividing the casing into upper and lower compartments, a motor and pump rigidly connected together to form an integral unit, means supporting said unit in the upper compartment for movement axially of the casing, a curved guide tube in the lower compartment communieating at one end with the bottom of the upper compartment and communicating at the other end with an aperture in the side wall of the lower compartment, a flexible shaft in said guide tube, said shaft having one end connected to the motor shaft and having a bit connected to the other end whereby a downward movement of said unit relative said casing causes said shaft to issue from said aperture and advance the bit laterally, said pump having its intake connected -to said lower compartment and its exhaust connected to the upper compartment whereby they form suction and pressure compartments respectively, and a port in the wall of the suction compartment for admitting fluid thereto from the well bore.

12. In a side drill for a well bore, rigid tubular 8 guide means having one end directed towards the surface to be drilled, means for driving-a bit member including a exible rotatable shaft and a surrounding non-rotatable flexible sheath, said lexible shaft and sheath being disposed in said tubular guide means and terminating at said one end in a bit member positioned adjacent said surface, means to support the other end of said exible shaft and sheath within said tubular guide means comprising a coiled spring within said guide means and surrounding said shaft and sheath, and mechanism to rotate and advance said shaft and sheath thereby to drill said surface.

ARMAIS ARUTUNOFF.

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

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