Title:
Pipe cutter
United States Patent 2203011


Abstract:
This invention relates in general to a pipe cutter, and more specifically has reference to a pipe cutter of that type designed to move into the interior of a drill pipe and to cut the same from within at a predetermined point. In the drilling of oil wells and the like it is not an infrequent...



Inventors:
Ellis, Guy P.
Ellis, James T.
Application Number:
US13566537A
Publication Date:
06/04/1940
Filing Date:
04/08/1937
Assignee:
Ellis, Guy P.
Ellis, James T.
Primary Class:
Other Classes:
30/106
International Classes:
E21B29/00
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Description:

This invention relates in general to a pipe cutter, and more specifically has reference to a pipe cutter of that type designed to move into the interior of a drill pipe and to cut the same from within at a predetermined point.

In the drilling of oil wells and the like it is not an infrequent occurrence for casing or a drill stem to become stuck in a well hole in such a manner that it becomes impossible for it to be 30 removed in the ordinary manner by pulling upwardly thereon. In such instances, it becomes necessary to lower into the well a pipe cutter having blades which may be expanded in a radial direction and a means by which the cutter may be moved to sever the pipe which has been stuck, and pull it out piece by piece. Numerous pipe cutters have been designed for the purpose set forth, the blades of such cutters being operated principally either by manipulation of the tubing by which the cutters are constantly suspended, or by means of energy in the form of fluid pressure or electrical energy transmitted from the surface of the hole.

It is an object of this invention to provide a cutter of the type set forth in which the cutter may be firmly and positively anchored prior to the expansion of the cutter blades.

It is a further object to provide such a cutter with a positive means for releasing the cutter from its anchorage.

Another object is to provide a pipe cutter in which blades of the cutters will have the maximum amount of radial movement for a minimum amount of longitudinal movement with respect to the pipe to be cut.

Another object of this invention is to provide a pipe cutter of the type set forth in which it will be impossible for the blades to be expanded until the cutter has been firmly anchored within the pipe.

Another object is to provide a pipe cutter of the type set forth with a means for positively and releasably preventing the actuation of the anchoring means.

Another object of this invention is to provide in a cutter of the type set forth a latching means which will prevent the actuation of the anchoring means, and which will be rotatable with respect to the anchoring means during the operation of the cutter.

One other object of this invention is to provide a pipe cutter which will pass through the reduced bores of the tool joints of a drill stem, and which may be anchored within a drill stem for the pur5B pose of severing a portion of the same.

Another object of this invention is to provide a pipe cutter of such a diameter that it will pass through the reduced portion of the tool joint of the drill stem and which may be anchored within the drill stem in such a manner as to sever the drill stem at a point where the wall thereof is thinnest.

Other objects and advantages of this invention will become apparent from the. following description taken in connection with the accom- 1i panying drawing, both of which are by way of illustration only. It is to be understood that this invention is to be limited only by the prior art and by the terms of the appended claims.

In the drawing: Fig. 1 is a view taken in vertical cross section illustrating a pipe cutter constructed in accordance with this invention in place within a pipe which is to be cut thereby.

Fig. 2 is a view partly in vertical cross section ~0 illustrating in elevation a portion of the device shown in Fig. 1.

Fig. 3 is a view similar to a portion of Fig. 1 but illustrating the parts with the blades in their cutting position, and the anchoring means anchored '2 within the internally upset end or joint portion of an internally upset section of drill pipe.

Fig. 4 is a horizontal cross section taken along the line 4-4 of Fig. 1.

In Fig. 1 there is illustrated a pipe I which is adapted to be severed by the cutter shown. This cutter is suspended upon a pipe or tubing 2 having a special shaft 3 secured thereto at its lower end.

Intermediate its ends the special shaft 3 is provided with laterally extending lugs 4 for a purpose to be presently set forth, and at its lower end is provided with a female thread at 5 to receive the upper end of a second special shaft 6. To the lower end of this special shaft 6 there is secured an end mill member 7 which serves as a guide for the device as it is being lowered into the well and with which a collapsed or constricted portion of the pipe may be opened up.

Intermediate its ends, the special shaft 6 is provided with milled out portions 9 having substantially parallel surfaces intermediate their ends, and having outwardly tapered or flared surfaces adjacent their ends as shown at 10. At substantially the opposite ends of the milled out portions 9 this shaft 6 is also provided with key ways for the purpose of receiving the laterally extending keys II, the same being secured in place within the shaft by means of pins 12 or the like. These keys extend beyond the shaft on each side thereof and lie in substantially the same s5 plane. Their corners adjacent the milled out portions 9 are beveled so as to form substantial extensions of the beveled end surfaces 10 of said milled out portions. This is illustrated at 13 in the drawing and clearly appears in Figs. 1 and 3.

Surrounding this portion of the shaft 6 and slidably mounted on the shaft is a sleeve 14 having longitudinal slots 15 therein so limited as to slidably receive the protruding ends of the keys 11. Cutter blades 16 mounted on cutter arms 17 are carred by this sleeve within the said slots, these arms being pivotally mounted upon pins 18 extending across the slots as clearly illustrated in Fig. 1. These cutter arms 11 are of such length that their opposite ends will be in constant contact with the flared end surfaces 10 of the milled out sections of the shaft 6 and with the extensions of these surfaces as formed by the beveled edges of the keys I1. It will be seen that as the shaft 6 is moved upwardly with respect to the sleeve 14, the surfaces 10 and 13 previously referred to will operate as cams to cause the cutter arms T1 to pivot about their axes 18 and to move the cutter blades 16 into contact with the inner surface of the pipe I within which the cutter is positioned.

The sleeve 14, however, is normally held in its upper position with respect to the shaft 6 as illustrated in Fig. 1 by means of a spring 19 bearing at its lower end against the upper surface of the end mill 7 and at its upper end against the lower end of the sleeve 14.

Located at the upper end of the sleeve 14 is an externally tapered expansion ring 20 adapted to contact with the inner surface of and expand a set of slip segments 21 into contact with the inner surface of the passage 22 through the upset end of the section of drill pipe. It is to be understood that while the cutter is shown as being anchored within the upset end portion of a section of pipe, it may be anchored at any point within the reduced passageway in or adjacent the tool joint. The ring 20 is freely slidable upon the shaft 6 and the slip segments 21 are formed integral with a ring-like portion 23 from which they are suspended. The upper end of this ring-like portion 23 is threaded to receive a fitting 24 forming one race of a set of ball bearings 25. The other race for this set of ball bearings is formed by a fitting 26 which is in turn threaded to the lower end of a sleeve 27. The sleeve 27 is thus rotatably-connected to the ring 23 with which the slip segments 21 are integral and from which they are suspended.

The sleeve 27 is provided in its opposite faces with slots 28 of J formation as illustrated in Fig. 2, the laterally extending portion of the J being at the lower ends of these slots. The lugs 4 which were previously referred to are of such a size and in such a position as to move within these J slots, and it is contemplated that they will occupy therein the positions illustrated in Figs. 1 and 2, respectively.

In operation, the cutter is lowered into the pipe to be cut upon the string 2 with the lugs 4 in the position in their J slots 28 as shown in Fig. 2. When in this position, the sleeve 27 through the medium of the bearings 25 will hold the slip segments 21 in their upper position with respect to the shafts 3 and 6, and these slip segments will be prevented from moving downwardly along the shafts into contact with the ex.terior surface of the expanding ring 20 which rests on top of the sleeve 14.

During this lowering of the cutting tool, if a collapsed portion of the drill stem should be encountered, or if it should be found to be plugged by some foreign substance, a rotation of the suspending string 2 will cause the end mill 1 to mill through and remove the obstruction, thus opening the path for the tool to be lowered into the drill stem. During this rotation, the lugs 4 will not be disengaged from their J slots because such rotation will tend only to more firmly engage these lugs in the lower ends of these slots. It is to be understood that the slip segments are so formed that in their passage downwardly through the drill stem and during the time they are being held out of engagement with the expanding ring 20, they will not contact the interior of the drill pipe proper except at the internally upset portions thereof and within the tool joints themselves. At these portions of reduced diameter, however, the slip segments 21 will contact with the inner surface of the bore, and will sufficiently retard the progress of the cutting tool so that the retarding effect may be noted at the surface of the well by means of a weight indicator or similar device.

When the approximate position is reached where it is desired to sever the pipe 1, the tubing string 2 will be lowered or raised slowly until the weight indicator shows that the slips are exerting a retarding effect upon the movement of the cutting tool, this being an indication that the slip segments 21 are positioned within a section of the drill stem of reduced diameter such as within the tool joint itself or within the upset end portion of a section of drill pipe. The string 2 by which the cutting tool is suspended will then be rotated to the left slightly to disengage the lugs 4 from the lower laterally extending portions of the J slots 28. Thereupon, the string 2 will be moved upwardly and since the sleeve 27 is no longer latched against longitudinal movement with respect to the shaft 3, the slip will remain in position and the expanding ring 20 will be moved upwardly into engagement therewith. Acting through the spring 19 and the sleeve 14 further upward movement of the string 2 will wedge the expanding ring 20 tightly within the slip segments so as to anchor the cutting tool with the cutter blades 16 positioned a substantial distance below the re- 5 stricted or tool joint portion of the drill stem.

After the slips are firmly set, further upward movement of the string 2 will compress the spring 19 and cause the shaft 6 to move upwardly with respect to the sleeve 14. This movement, as hereinbefore pointed out, will cause the cutter arms IT to be rotated about their pivotal supports 18 until they occupy a position somewhat as shown in Fig. 3. During this time, the spring 19 is being compressed so that a constant upward pull must be exerted upon the string 2 in excess of its weight to hold the cutter blades against the inner surface of the pipe to be cut. The string 2 is then rotated to cause the cutter blades to cut the inner surface of the pipe and as the cutting proceeds the string 2 will be gradually drawn upwardly until the pipe is completely severed. It is to be noted that during this operation the position of the cutter arms and hence of the blades 16 may be accurately and positively controlled by virtue of the fact that both ends of the cutter arms are in contact with actuated cam surfaces at all times. Thus, it is possible to positively prevent the cutters 16 from hogging the cut and becoming stalled or broken. t It is further to be noted that during this expanding movement of the cutting blades 16 the blades and arms on which they are mounted do not move either upwardly or downwardly. Instead, they are anchored positively against upward longitudinal movement with respect to the pipe being cut, and are constantly urged upwardly so that they have no downward movement with respect to such pipe.

During the rotation of the string 2 for the purpose of cutting the pipe, the keys II projecting as they do from the lateral surfaces of the shaft 6 into the slots 15 in the sleeve 14, will directly cause the rotation of this sleeve, thus positively driving the cutter blades in their rotational movement.

The lugs 4 remain at all times within the J slots in which they operate, and the sleeve 27 in which such slots are formed is freely rotatable with respect to the slips and the ring 23 from which they are suspended. There is thus no problem of guiding the lugs 4 back into the J slots.

After the pipe within which the cutter has been anchored is severed as previously described, the string 2, together with the shafts 3 and 6, will then be lowered. During the initial part of this lowering operation the spring 19 will expand so that the shaft 6 will move downwardly with respect to the sleeve 14 and retract the cutter blades before they are moved longitudinally with respect to the pipe. Further downward movement of the shaft 6 will permit the sleeve 14 to move away from the expanding ring 20 until the lower end of the shaft 3 which is of slightly larger diameter than the shaft 6 strikes the upper end of the expanding ring 20. This will move the expanding ring from its position within the slips and permit the shafts 3 and 6 to move downwardly still further with respect to the slips. The lugs 4 upon reaching the lower ends of the J slots may by right hand rotation of the string 2 be caused to engage the lateral portions of the J slots and upon upward movement of the string 2 the sleeve 27 and the slips 21 will be moved with the string. Another location for cutting may then be selected and another cut made, or the cutter may be removed from the hole, as desired. It is noteworthy that after the pipe has been severed, the cutter may be moved either upwardly or downwardly in the same manner as before the pipe was severed.

From the foregoing it will be seen that there has been provided a pipe cutter which may be lowered through the portions of restricted diameter of a drill stem, and which may be anchored within the drill stem in such a manner as to sever the same at a position where the walls of the drill pipe are thinnest. Means has been provided 1)0 whereby this cutting device may be operated easily and rapidly while being positively controlled at all times. It may be made of sufficiently small diameter to pass through the restricted portions of the drill stem, and because it is adapted to anchor within such restricted portions, it is unnecessary that the anchoring means be greatly expanded during the anchoring operation.

While one embodiment of this invention has been set forth by way of example, it is to be understood that various changes and modifications may be made therein without departing from the spirit or scope of this invention as defined in the appended claims.

Having described our invention, we claim: 1. In a pipe cutting device, a cutter support, means for anchoring said cutter support-against upward movement in a pipe to be cut, expansible cutters mounted in said cutter support, an actuator member movable longitudinally with respect to said cutter support to cause expansion and contraction of said cutter blades, means slidably interconnecting said actuator and said cutter support whereby rotation of said actuator will cause rotation of said cutter support and said cutter, means on said actuator for releasably securing said anchoring means in inactive position, and means for normally urging said actuator in the direction with respect to said cutter support such as to cause contraction of said blades.

2. In combination, in a cutting device for severing a pipe having parts of larger and other parts of smaller inner diameter an anchoring means adapted to pass freely through the portions of such pipe of larger inner diameter, and to resiliently engage the portions of such pipe of smaller internal diameter, an actuator for extending through such pipe and having parts thereon forming a latching device and detachably maintaining said anchoring means in inactive position, a cutter support resiliently supported upon said actuator, means carried by and rotatable with respect to said cutter support for actuating said anchoring means upon upward movement with respect thereto, cutter blades on said cutter support, and means on said actuator operable upon upward movement of said actuator with respect to said cutter support to expand said blades and upon rotative movement of said actuator to rotate said cutter support and said blades.

3. In combination, in a means for severing a pipe having internally upset portions, a shaft adapted to extend into such pipe, a cutter-carrying sleeve resiliently, slidably and non-rotatably supported upon said shaft, an upwardly tapered wedge ring freely movable upon said shaft and rotatably supported on said cutter-carrying sleeve, an expansible anchoring means slidable and rotatable with respect to said shaft above said ring and adapted upon upward movement of said shaft with respect to said anchoring means to be expanded by said ring into anchoring position within such pipe, said anchoring means when not expanded being of a size to pass freely through the portions of said drill stem of larger diameter and to frictionally engage the internally upset portions, a sleeve for rotatably supporting said anchoring means out of contact with said ring, an anti-friction bearing rotatably connecting said sleeve and said anchoring means, a closed J slot connection between said sleeve and said shaft whereby said sleeve may be latched in an upper position with respect to said shaft to support said anchoring means out of contact with said ring, expansible cutter blades carried by said cutter-carrying sleeve, means on said shaft adapted upon upward movement of said shaft with respect to said cutter-carrying sleeve to expand the cutters thereon into cutting engagement with such pipe, and on downward movement of said shaft with respect to said cutter-carrying sleeve to retract the cutters from such cutting engagement, means for resiliently urging said shaft downwardly with respect to said cutter-carrying sleeve, and means on said shaft to force said wedge ring out of expanding contact with said anchoring means upon further downward movement of said shaft after said blades have been retracted.

4. In combination, means for severing a pipe comprising a shaft adapted to extend into such pipe, a cutter-carrying sleeve resiliently, slidably and non-rotatably supported upon said shaft, an upwardly tapered wedge ring freely movable upon said shaft and rotatably supported on said cutter-carrying sleeve, an expansible anchoring means slidable and rotatable with respect to said shaft above said ring and adapted upon upward movement of said shaft with respect to said anchoring means to be expanded by said ring into anchoring position within such pipe, supporting means for rotatably supporting said anchoring means out of contact with said ring, an antifriction bearing rotatably connecting said supporting means and said anchoring means, a closed J slot connection between said supporting means and said shaft whereby said supporting means may be latched in an upper position with respect to said shaft to support said anchoring means out of contact with said ring, expansible cutter blades carried by said cutter-carrying sleeve, and means on said shaft adapted upon upward movement of said shaft with respect to said cutter-carrying sleeve to expand the cutters thereon into cutting engagement with such pipe. 5. In a means for severing a pipe, a shaft adapted to extend into said pipe, a cutter-carrier resiliently, slidably and non-rotatably supported upon said shaft, an upwardly tapered wedge member freely movable upon said shaft and rotatably supported on said cutter-carrier, an expansible anchoring means slidable and rotatable with respect to said shaft above said member and adapted upon upward movement of said shaft with respect to said anchoring means to be expanded by said member into anchoring position within said pipe, supporting means for rotatably supporting said anchoring means out of contact with said ring, a bearing rotatably connecting said supporting means and said anchoring means, a releasable connection between said supporting means and said shaft whereby said supporting means may be latched in an upper position with respect to said shaft to support said anchoring means out of contact with said wedge member, expansible cutter blades carried by said cutter-carrier, and means on said shaft adapted upon upward movement of said shaft with respect to said cutter-carrier to expand the cutters thereon into cutting engagement with said pipe.

GUY P. ELLIS.

JAMES T. ELLIS.