US2158243A - Casing cutter - Google Patents

Description

J. J. MCCANN CASING CUTTER May 16, 1939.

Filed March s, 193e Juve/W10@ wnmmm@ Patented May 16, 1939 PATENT OFFICE CASING CUTTER,

Judson J. McCann, Lake Charles, La.

Application March 3, 1938, Serial No. 193,774

4 Claims.

This invention relates to a. casing cutter and has relation more particularly to that type known as inside cutter, and it is primarily an object of the invention to provide a tool of this kind which can be used to bring in wells from open sand at any depth afterk the casing has been set to a depth.

It is also an object of the invention to provide a cutter of this kind embodying cutting members adapted to maintain effective cutting relation with respect to the casing to be cut by uid pres- Vantageous for use, as will be hereinafter more lll) fully set forth.

The novel features of my invention will hereinafter be definitely claimed.

In order that my invention may be the better understood, I will now proceed to describe the same with reference to the accompanying drawing, wherein:

` Figure 1 is a sectional view with parts in elevation of a cutter constructed in accordance with an embodiment of my invention and in applied position within a casing, the cutting members being shown retracted in full lines and the extended adjustment of the cutters being indicated by broken lines;

Figure 2 is an enlarged fragmentary sectional view with parts in elevation showing the cutting members fully extended and after cutting through the casing;

Figure 3 is a sectional view taken substantially on the line 3-3 of Figure l, the casing being omitted.

As disclosed in the accompanying drawing, C denotes a casing in which my improved tool is adapted to work. As herein disclosed my improved tool comprises an elongated tubular central body I having a top section or head 2 threaded thereon and the lower end portion of the section I has threaded therein a bottom section 3. This bottom section 3, as herein disclosed, has an extension lll which slips up within the lower portion of the bore of the member or section I and this bottom section 3 and its extension 4 have provided therethrough a bore 5 opening into the bore a of the section or member I. The side wall of the member or section I at equidistantly spaced points therearo-und is provided with the longitudinally disposed slots 6 herein disclosed as four in number, and the top wall of each of the openings 6 is disposed on an upward and inward bevel,

as at l, of approximately forty-rive degrees although this angle may be varied as preferred.

Intersecting each of the slots or openings 6 at the upper portion thereof is a pivot pin 8 upon l which is mounted for rocking movement a cutting member or mill 9. The cutting member or mill 9 is extended at its pivoted end by an upwardly disposed tail piece I which has its outer face inwardly tapered whereby the outer or upper extremity of the tail piece I0 is pointed for effective engagement within an annular pocket or recess I I provided in the under or lower end face of a mandrel I2. This mandrel I2, as herein disclosed, is integrally formed with an elongated tubular rod I4 open at both ends and the lower end portion of which at all times is telescopically engaged within the bore of the extension 4 of the lower section 3.

The mandrel I2 snugly engages within the bore a of the section I but freely moves therealong. The upward movement of this mandrel I2 and also of the rod I4 is limited by contact of the mandrel I2 with an inwardly disposed internal annular flange I5 positioned substantially midway the length of the section I. This flange I5 defines a central opening through which the upper portion of the rod I4 is snugly and slidably directed. This flange I5 also provides a stop or abutment for an expansible member I6 of desired tension and which is herein disclosed as a coil spring encircling the portion of the rod I4 above the flange I5.` This member or spring I6 also bears against a piston I1 preferably of rubber andwhich piston is snugly fitted within the upper portion of the bore a of the section I.

The rod I4 extends, as at I8, above the piston I 'I and suitably secured to said extended portion I8 is a cage I9 for a valve member 20, herein disclosed as a ball, whichoperates to prevent downward Vor retrograde ow through the bore of the rod I4. The member or spring I6 is of a tension suicient to normally maintain the mandrel I2 at the limit of its upward movement so that the supplemental mandrel 2 I, carried by the rod I4 at a desired distance below the mandrel I2, will maintain the cutting members or mills 9 in their fully retracted position as is 'illustrated in Figure 1. It is to be noted that the inner face of each of the cutting members or mills 9 including the tail piece Il! is straight from end to'end so that the mandrel 2| may readily contact therewith and maintain the cutting member or mill 9 fully retracted under normalconditions.

The upper portion of the mandrel 2| is inwardly tapered, as at 22, to facilitate the desired action of the mandrel upon the cutting members or mills as the rod I4 is moved upwardly under the action of the member or spring I6 to return the mandrel I2 to its normal position. To assure the desired functioning of the mandrel 2| it must, of course, be of a diameter l-ess than the diameter of the bore a of the section I.

The pocket or recess II in the under surface of the mandrel I2 generally speaking is conoidal, that is to say, its bottom wall is inclined inwardly and upwardly so that as the rod I4 is forced downwardly the contact of the mandrel I2 with the pointed extremities of the tail pieces Ill for the cutting members or mills 9 will cause the lower ends of the cutting members or mills 9 to be forced outwardly through the slots 6 into contact from within the casing C so that as the rotary mechanism is put into operation the cutting members or mills; 9 will have proper cutting engagement with the casing and so maintained until the casing is entirely cut through.

The top section 2 is adapted to be coupled, as at 23, with a stem or string 24 through the medium of which the tool is lowered t the desired depth within the casing. After the tool has been lowered as desired, the pump is started and the pressure of the mud received within the section I above the piston I'I will force said piston downwardly to make the proper contact of the members or mills 9 with the casing C and maintain such contact until the casing is completely cut out. At the completion of this cutting action the pressure upon the piston will then force the same beyond the suitably positioned iluid outlets 25 which are continued by the pipes 26 to a point adjacent the members or mills 9. When these outlets 25 are opened the pressure of the pump will be relieved permitting such pressure to run freely and thus indicating to the operator that the casing has been cut through. Upon stopping of the pump the member or spring IS will cause the rod I4 to move upwardly to bring the mandrel I2 to its normal position with a resultant retraction of the members or mills 9.

When the pump is in operation the valve member 20 will close the bore of the rod I4 against ow therethru. However, in lowering'the tool within the casing this valve 20 will readily open to relieve any resisting pressure which may be offered to such lowering of the tool.

While I have particularly referred to my improved tool as a casing cutter, it is to be understood that after the casing has been cut through weight can be applied and a section of the casing milled away in order to leave an open section where there is clean oil sand.

From the foregoing description it is thought to be obvious that a casing cutter constructed in accordance with my invention is particularly well adapted for use by reason of the convenience and facility with which it may be assembled and operated, and it will also be obvious that my invention is susceptible of some change and modification without departing from the principles and spirit thereof and for this reason I do not wish to be understood as limiting myself to the precise arrangement and formation of the several parts herein shown in carrying out my invention in practice except as hereinafter claimed.

I claim:

1. A casing cutter comprising an elongated tubular section, a tubular bottom section engaged therewith, an elongated rod within the elongated section .and having an end portion telescoping in the bottom section, a piston carried by the opposite end portion of the rod and snugly engaging within the elongated section, a top section for the elongated section, said top section having connection with a stem, said elongated section having an internal shoulder, an expansible member interposed between the shoulder and the piston, slots in the lower portion of the Wall of the elongated section, cutting members, means for pivoting said members to the elongated section to allow said members to swing outwardly through the slots, said cutter members having upwardly disposed tail pieces, said tubular rod having a conoidal face to engage the tail pieces for swinging the cutting members outwardly upon downward movement of the piston and rod, the inner faces of the cutting members being straight, and a mandrel carried by the rod for engagement with the straight faces of the cutting members for retracing the cutting members and maintaining such members retracted upon upward movement of the rod and piston.

2. A casing cutter comprising an elongated tubular section, a tubular bottom section engaged therewith, an elongated rod within the elongated section and having an end portion telescoping in the bottom section, a piston carried by the opposite end portion of the rod and snugly engaging within the elongated section, a top section for the elongated section, said top section having connection with a stem, said elongated section having an internal shoulder, an expansible member interposed between the shoulder and the piston, slots in the lower portion of the wall of the elongated section, cutting members, means for pivoting said members to the elongated section to allow said members to swing outwardly through the slots, said cutting members having upwardly disposed tail pieces,

and a mandrel carried by the rod, said mandrel having its bottom face conoidal to engage the tail pieces as the rod moves downwardly to swing the cutting members out through the slots.

3. A casing cutter comprising a tubular member having a slot in its side wall, a cutting member, means for pivotally mounting the cutting member upon the tubular member, said member having a tail piece extending within the tubular member in all positions of the cutting member about its pivot, and a movable actuator within the body for the cutting member, said actuator having means thereon to engage one edge face of the cutting member upon movement of the actuator in one direction to move the cutting member outwardly from the body thru the slot, said actuator having additional means to contact with a second edge face of the tail piesv of the cutting member upon movement of the actuator in the opposite direction to retract the cutting member.

4. A casing cutter comprising a tubular member having a slot in a wall thereof, a cutting member pivot-ally carried by the tubular member and having movement inwardly and outwardly of said member through the slot, said cutting member having a tail piece extending within the tubular member, a movable actuator for the cutting member within said tubular member, said actuator having a conoidal recess, the wall of which contacting with one edge of the tail piece upon movement of the actuator in one direction to swing the cutting member outwardly beyond the tubular member, said actuator also having a tapered portion for contactwith a second edge face of the tail piece upon movement of the actuator in the opposite direction to retract the cutting member. i

JUDSON J. MCCANN.

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