US1796546A - Expanding rotary underreamer - Google Patents

Description

March 17, 1931- J. B. TRIPLETT EXPANDING ROTARY UNDERREAMER Original Filed April 16, 1923 2 Sheets-sheet 1 JYI L YTOZ JQMES B 7k/PLET 7,

ATTORNEYS March 17, 1931. J, TR|PLETT 1,796,546

EXPANDING ROTARY UNDERREAMER Original Filed April 16, 1923 V 2 Sheets-Sheet 2 M/Wrok Jan x55 5. 7720 4 5 T r,

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Patented Mar. 17, 1931 um'ren sr'rss PATENT OFFICE JAMES B. TRIPLETT, OF HITTIER, CALIFORNIA; WILLIAM H. CAMPBELL, OF LOS ANGELES, CALIFORNIA, AND WILLIAM H. MAXWELL, OF BEVERLY HILLS, CALI- FORNIA, EXECUTORS 0F SAID JAMES. B. TRIPLETT, DECEASED, ASSIGNORS TO JOHN GRANT, OF LOS ANGELES,

CALIFORNIA EXPANDING RDTARY UNDERREAMER Application filed April 16, 1923, Serial No. 832,295. Renewed December 12, 1927.

This invention relates to rotary well drilling equipment and relates particularly to expanding underreamers employed in rotary well drilling equipment.

I In drilling oil wells, considerable, difficulty is encountered in maintaining the full diameter of the bore, because of the wearing oit of the corners and the sides of the drill bit, so that the bit will not cut a hole to the intended full diameter. It is necessary that the full diameter of the hole he maintained in order that the well casing may enter freely into the well as it is installed. It is necessary, under this condition, to'employ an underreamer to ream the hole to the full diameter to permit the casing to advance. l

The underreamer generally employed for this purpose is of the expanding blade type,

which is lowered through the casing to the point at which it is to operate and the blades thereof expanded. In order to employ an underreamer of this type, it is necessary to pull the drill and attach this underreamer to the lower end of. the drill tubing and then to lower the underreamer into the well. Before drilling can then be resumed, the underreamer must be removed from the well and replaced by the bit. It will be readily seen that much time is consumed by the changing of tools, and that when drilling through hard rock, where the drill wears very quickly, most of the time is spent in removing and replacing tools.

It is an object ofthe invention to provide 5 an underreamer which is screwed to the Referring to the drawings, which are for illustrative purposes only:

' Fig. 1 is a diagrammatic view illustrating the utility of my invention.

Fig. 2 is a vertical section of my invention showing the reaming elements in retracted As shown in Fig. 1, a well 11 is being drilled by a bit 12 which is attached below an underreamer 14. embodying the features of my invention to a drill tubing 15. The drill tubing is rotated by a rotary table 16 located at the surface, which causes the drill to sink the hole. In time, the drill will so wear that it will not cut the hole to the full diameter required, and it would be impossible to advance the well casing 17 downwardly if it were not for the underreamer 14:. The underreamer 14 has reaming elements which are in reaming position during the time thebit12 is working, and as the drill wears and begins to cut the hole slightly undersize, the reamer elements will maintain the hole to a suflicient size to allow the casing 17 to be advanced. 'VVhen it is necessary to pull the drill tubing to replace the drill after it has Worn considerably so that it will not cut efiiciently, the

underreamer is so constructed that the reamer elements will be .retracted into a position within the body of the underreamer and will 7 pass through the well casing without interference.

In the remalnlng figures I'show an underreamer of my invention, in detail. The underreamer l lconsists of a main body 20 comprising an upper section 21 and a lower section 22. The upper section has a threaded pin 23 at its upper end for attachment to the drill pipes, and has a reduced rectangular portion 24 at its lower end which has a tapered dovetail slide 25 symmetrically disposed at its lower end, and which portion extends into the slides in a corresponding opening 26 formed in the lower member 22. The members 21 and 22 are in limited sliding relationship, and, as shown in Fig. 4, the upper end of the member 22 is provided with slide limiting studs 28 which extend through holes 29 in the member 21 into recesses 30 provided in the member 21. When the members 21 and 22 are together, as shown in this figure and in Fig. 3, the top face 31 of the member 22 and the face 32 of the member 21 are together, and when the members 21 and 22 are apart, as shown in Fig. 2, the nuts 34 on the upper end of the studs 28 engage the face 36 of the recess 30. The lower member has a threaded box 37 by which a bit may be attached thereto and has a slot 38 therein in which the remaining elements 40 are located. These reaming elements 40 are of circular cross section and the surface thereof is prepared in tooth formation to form an eiiicient reaming engagement with the wall of the hole, and these reaming elements 40 are rotatably mounted between blocks 41 and pivoted members 42. The blocks 41 are slidably engaged with the dovetailed slides 25, and the members 42 are pivotally mounted on pins 43, which members have the lower faces 44 thereof formed concentric with the pins 43 and rest on the bottom of the slot 38, so that any stress placed on the reaming elements 40 will be supported by the faces of the slots and not the pins 43, which are merely retainers.

It will readily be seen that by providing reaming elements of circular cross-section and by rotatably mounting them, that a very extensive cutting surface may be provided.

As hereinbefore mentioned, the reamer elements are adapted to assume two positionsthe reaming or expanded position and the non-reaming or retracted position, the manner in which these two positions are controlled will now be described:

When the drill bit is in operation most of the weight of the drill tubing thereabove is placed on the bit, the weight sliding the members 21 and 22 together, as shown in Fig. 3. In this figure, the wide portion of the dovetailed slide 25 is engaging the blocks, and the reaming elements 40- are in expanded or reaming position and remain in this position during the drilling operation. When the drilling is stopped, possibly to replace the drill, and the drill tubing is moved upward, the upward movement of the tubing first moves the upper member 21, the lower member 22 and the drill remaining stationary until the nuts 34 on the members 28 are engaged' by lower face 36 of the recess 30; then the lower portion 22, and the drill are carried upwardly therewith. As shown in Fig. 2, the relational movement of the members 21 and 22 moves the slide 25 upwardly also and brings the narrow portion of the slide into engagement with the blocks 41 causing them to move inwardly and to swing the reaming elements inwardly into non-reaming position. lVhen the reaming elements are in this position they are resting within the body of the underreamer and will in no way interfere with the lowering or raising of the underreamer through the casing. To prevent any drillings or mud from lodging between the faces 31 and 32 of the members 21 and 22, I provide a protective sleeve which is mounted on the upper member 21 and extends around the upper portion of the lower member 22. The sleeve 50 also encloses the recesses 30, into which the slide limiting studs extend.

Lubricating mud may be conducted to the bit through the passage 53 which extends through the upper member 21 and the pipe 54 which is screwed to the lower end of the slide 25, the lower end of which passes through the packing gland 55 to compensate for the sliding relationship of the members 21 and 22.

From the foregoing, it will be seen that a great deal of time is saved by eliminating the necessity of removing the bit to ream the hole to a size suflicient to allow the well casing to be advanced.

t will also be recognized that with the construction I employ a positive operation of the reamer elements between expanded and retracted positions is accomplished.

This application is companion to a later one filed May 10th, 1926, Ser. No. 107,999 and similar in subject matter. The common subject matter of the two is herein claimed; claims of the later application are limited to to its differences over this one.

I claim as my invention:

1. A rotary well underreamer of the character described including two body sections movable relative to each other longitudinally of the underreamer, one of the body sections having a. channel, a projection on the other body section extending into the channel, expansibly disposed and separately rotatable reamer elements each pivotally connected at its lower end to one of the body sections and slidably connected at its upper end to the other body section, and means whereby said reamer elements are expanded when said body sections are relatively slid in one direction and are retracted when said body sevtions are relatively slid in the opposite direc tion, said means including a tapered dovetail slide.

2. A rotary well underreamer including a body composed of two relatively longitudinally movable sections adapted to be secured one to a drill string and the other to carry a rotary bit, expansible and separately rotatable reamer members supported upon said body, said reamer elements each having one end pivotally connected and the other end shiftably connected to said body for radial movement, and means whereby said reamer elements are expanded when said body sections are relatively slid in onedirection and are retracted when said body sections are relatively slid in the opposite direction, said means comprising symmetrically disposed tapered slides for expanding said reamer members into cutting position when the weight of the above drill string is placed upon the body.

3. In an underreamer, the combination of: a body adapted to incorporation in a drill string; expansible reamer members support-- ed upon said body, consisting of abrading rollers of tapered form pivotally secured at their smaller ends, with their larger ends swingable between retracted and expanded position; and means for expanding said reamer members into cutting position when the weight of above drill pipe is placed upon said body.

4:. In a rotary underreamer oi the character described, the combination of: a pair of relatively slidable members comprising an upper member provided with a pin and a lower member adapted to carry a terminal bit; a projection extending from one of said members into the other of said members for transferring torque between said members; separably rotatable reamer elements having their lower ends pivotally connected to one of said members and their upper ends slidably connected to the other member; and means on said upper member for expanding said reamer elements when said members are moved together.

5. In a rotary underreamer of the character described, the combination of: a pair of relatively slidable members comprising an upper member and a lower member; a projection extending from one of said members into the other of said members for transferring torque between said members; separably rotatable reamer elements pivoted at their lower ends to one of said members and slidably connected at their upper ends to the other member; and means on the other of said members for moving the upper ends of said reamer elements outwardly into expanded position when said members are moved together. I

6. In an underreamer, the combination of a pair of relatively slidable members comprising an upper member and a lower memher; a projection extending from one of said members into the other of said members for transferring torque between said members; roller reamer elements pivotally mounted at their lower ends to one of said memupper ends of said reamer elements; and a wedge member for forcing said blocks outwardly into expanded position when said relatively slidable members are moved together.

7. In an underreamer, the combination of, a body comprising two relatively moving parts sliding longitudinally of each other, one of said parts having a wedge surface, a block slidably engaging the wedge and adapted to be moved laterally by relative longitudinal movement of the wedge, a cutter carrier pivotally mounted at one end on the other body part and connected at its other end loosely with the block to allow sliding of the block and swinging of the carrier about its pivot, and a cutter mounted on the carmen 8. In an underreamer, the combination of, a body comprising two relatively longitudinally movable parts, one of said parts being tubular and having slotted walls, and the other entering the tubular part and slidable longitudinally therein; a longitudinally extending cutter carrier pivoted at one end to the tubular body part and lying in the body slot, an expanding wedge on the other body part, a block lying in the body slot and slidably engaging the wedge to be moved in and out through the slot by virtue of relative longitudinal movement between the two body parts, the other end of the cutter carrier being connected to the block in a manner allowing the block to slide and the carrier to tilt about its pivot, and a cutter mounted on the carrier.

9. In an underreamer, the combination of, a lower tubular body part having a slotted wall, an upper body part slidable vertically in the tubular part and having at its lower end a wedge, a block lying in one end of the body slot and slidably engaging the wedge to be moved in and out through the slot by virtue of relative longitudinal movement of the two body parts, a cutter carrier lying in the body slot and pivoted at one end to the tubular body part at the other end of the slot, the other end of the cutter carrier being loosely connected to the block allowing the block to slide and the carrier to tilt about its pivot, and a cutter mounted on the carrier.

In testimony whereof, I have hereunto set my hand at Los Angeles, this 3rd day of April,

JAMES B. TRIPLETT.

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