US2111464A

US2111464A - Underreamer

Info

Publication number: US2111464A
Application number: US112767A
Authority: US
Inventors: Swan Fred
Original assignee: Individual
Current assignee: Individual
Priority date: 1936-11-25
Filing date: 1936-11-25
Publication date: 1938-03-15
Anticipated expiration: 1955-03-15

Description

N A W s F UNDERREAMER '2 sheets-sheet 1 Filed NOV. 25, 1936 l f Il INVENTOR. f-Pe d Swan Patented Mar. 15, 1938 UNITED shares FATENT OFFICE 12 Claims.

The present invention consists of an underreamer especially adapted for use in oil wells and is an improvement on patents previously granted to me in this art, especially my Patents Numbers 1,372,917 and 1,578,482, as well as Swan Patent No. 997,718. While the Swan underreamers, now extensively used in this art, are effective for reaming a hole of greater diameter than the interior of the casing regardless of the strata formation of the earth, I have found that a more eiicient tool is provided by following the teaching of the present invention, a preferred form of which is illustrated in the accompanying drawings.

It is within the contemplation of this invention to retain cutters operated intoan expansive or operating position by an upwardly moving spring rod but the `mounting of the cutters has been modiiedito change the angularity of the cutters when in use to positively effect operation of the cutters through any of the variety of earth formation, whether hard or soit, with minimum wear on the tool and with a complete elimination of tool fracture, rupture or breakage, notwithstanding the fact that the working ends of the cutter may impinge against solid formation immediately on leaving the casing, the angularity of the cutters positively preventing their collapse when engaged with rock or like solid formations.

It is a further object of this'invention to provide expansible cutters, the work engaging terminals of which are free to permit contact of the complete terminals with the work, the conformation of the terminals and the angularity of cutter bodies permitting the wall to be attacked from above, after initial penetration of the wall surface, as well as at the side to more expeditiously and more effectively break down the wall, during which operation the line of stress is on the long axes of the cutters.

Another object of the invention is to provide a cross bar which is automatic in its operation to lock the spring rod and cutters together when the cutters are moved into an expanded position, 45 the bar being loosely mounted in the spring rod and cutters and being freely removable when the cutters are in a` collapsed position. It is also within the contemplation of the present invention to provide a detent, which is also automatic in its operation,V to secure the cutters in a co1- lapsed position, the detent being likewise automatically disengaged when the reamer is oper-V ated to permit the cutters to expand, the detent 55 being of peculiar design to assure its Velective operation over a long period of time without replacement.

Other objects of the invention will be apparent from the following description of the present preferred form of the invention, wherein:- 5

Fig; l is a vertical sectional View of an underreamer constructed in accordance with the present invention illustrating its application, showing the cutters in an expanded or operative position.

Fig. 2 is a similar view showing the cutters in a collapsed position within the confines of the casing. f

Y Fig. 3 is a fragmentary detail enlarged view of the reamer body showing the spring rod and detent in side elevation illustrating the manner in which the rod is held in a iixed position by the detent.

Fig. 4 is a detail fragmentary perspective view of one of the detents. 20

Fig. 5 is a side elevational view, partly in section, of a reamer body constructed in accordance with this invention.

VFig. 6 is an end elevational view of one of the cutters. Y

Fig. 7 is a fragmentary elevational viewof the reamer body showing the cutters mounted therein, the latter being in collapsed position.

Fig. 8 is a side Yelevational View of one of the cutters;V Fig. 9 is an elevational View of the spring rod Y constructed in accordance with the present invention.

' Fig. 10V is a side elevational view of an underreamer constructed in accordance with this invention showing the means of thepresent invention used for collapsing the cutters.

, Fig. 11 is a perspective view of the locking bar, and

Fig. 12 is a cross sectional view shown on the line IZ--IZ of Fig. 10,' looking in the direction of the arrows, illustrating the manner of mounting the releasing bar through the reamer body, above the spring rod. H

In the drawings for purpose of illustration, a portion of a Well casing i3 is shown which is of standard construction, and is mounted in the earth'in a manner well known in the art.

The tool constructed in accordance with the present ,invention includes a reamer body lli, the

, lowerV terminal of which is provided with recesses i5 in the sides thereof, the portions of the terminals below said recesses being rounded, as indicated atl I6. The inner Wall of each of. the

terminals I6 is rabbeted out to provide cutter 55 engaging recesses I'l. The reamer body I4 is provided with the usual bore I8, which is constricted, as indicated at I9, just above the rounded terminal I 6. The wall of the reamer body is provided with longitudinal slots in the opposite sides of the body, the slots being preferably formed at a point appreciably above the constricted bore I9.

Mounted for movement in the bore I 8 is a spring rod 2|, the upper end of which is formed to provide a head 22 in which a kerf 23 is formed. The lower end 24 of the rod is enlarged, the jointure of the rod proper and the enlargement lseing formed to provide bevelled shoulders 25. The lower end ofthe enlargement 24 is tapered to provide a truncated cone shape 'terminal 26. The enlarged end 24 of the rod is provided with a longitudinal slot 2'I which is adapted for the reception of a cross bar 28, the free ends of which project beyond the rod and engage complemental openings 29 formed in cutters 30. Preferably, the cross bar 28 is of the configuration shown in Fig. 1l of the drawings and includes flared terminals 3|. This contour of cross bar permits the latter to be freely engaged with and disengaged from the cutters and spring rod. However, when the cutters 38 are in an expanded position, as shown in Fig. 1 of the drawings, the inclined free faces of the ared ends 3l bear against the correspondingly formed upper walls of the openings 29 of the cutters, while the lower faces of said flared ends bear against the lower walls of the cutters thereby positively locking the cutters from displacement and also preventing the cross bar from any appreciable longitudinal movement of the cross bar. If perchance the cross bar should move lengthwise, in either direction during the operation of the tool, the conformation of the flared ends and the walls of. the cutters automatically returns the cross bar to a central or normal position, as shown in Fig. 1.

Each of the cutters 3U is provided at its upper or inner end with a boss 32 which complements and is movably engaged in one of the recesses I1 in the lower terminal of the reamer body. The upper or inner wall of each cutter is formed to provide an abrupt shoulder 33 which complements and is adapted for engagement in one of the recesses I5. By this formation the support of each cutter when in the expanded position shown in Fig. 1 of the drawings is on the line of impact ofthe cutter, the line of impact carrying substantially through the top of the axis of the cutter and the solid walls of the reamer body at diametrically opposite points. By this construction, excessive outward or expansive movement of the cutters is prevented, yet the free ends of the cutters are in no way restrained or housed leaving them free for engagement with the work. Preferably, the working terminal of the cutter is of substantially inverted V-shape configuration, as indicated at 34, it being preferred to slightly elongate the inner or trailing toothed portion of each cutter. The outer or entering toothed portion of each cutter, which is relatively shorter, is adapted for penetration in the wall, but is operated so as to rst bite into the wall surface and then tear down the sub-strata of earth regardless of its formation, The inner or trailing tooth of each cutter serves as a guide and as shown in Fig. 1 of the drawings normally remains slightly spaced from the wall being torn down.

In order to expand the cutters 30, as shown in Fig. 1 of the drawings, I provide the rod 2I with a spring 35, one end of the spring bearing against the head 22 while the opposite end bears against a permanent part of the reamer body just above the constricted portion I9 of the bore. Consequently pressure is exerted upwardly on the rod 2i which correspondingly urges the cross bar 28 upwardly and throws the lower or working ends of. the cutters outwardly into expanded position. This angularity of the cutters positively insures engagement of the outer toothed portions of the cutters with the wall and likewise prevents casual folding or collapsing of the cutters when solid formations are encountered during the reaming operation.

While the reamer is being passed through the casing, it is desired that the cutters be held in a collapsed or inoperative position and for this purpose I provide a detent 3S which is mounted through the wall of the reamer body and is adapted for engagement with one of the bevelled shoulders of the rod. Preferably, the rod engaging end of the detent is squared to provide a plurality of, flat faces 37, each of which is bevelled to conform to the contour of the shoulders 25 and anyone of which may be engaged with said shoulders. Consequently, as one of the square faces of the detent wears, the detent may be rotated to bring another face into use. Correspondingly, when one of the shoulders 25 begins to show wear, the rod 2| may be turned so as to bring the other shoulder into play. The detent is provided on its outer end with a head 38 which serves as an abutment for one end of a spring 39, the upper end of the spring bearing against the reamer body around the opening in the latter through which the detent moves. Consequently the detent is normally held disengaged from the rod 2 I. When the detent is in a disengaged position, it is retained from displacement by a screw cap 4G mounted in the .reamer body outside of the detent head 38. v When it is desired to collapse the cutter heads, downward pressure is exerted on the rod 2I in a manner hereinafter set forth, and at the same time pressure is placed on the head 38 of the detent by a suitable implement. As soon as the rod 2| has been depressed to the point where one of the shoulders 25 crosses said detent, the latter will automatically move into position above the shoulder as shown in Fig. 3. By releasing pressure on the rod 2l the detent and rod are frictionally locked in an apparent manner. When in a collapsed position the cross bar 28 is free to be engaged with or disengaged from the cutters and spring rod. To prevent accidental displacement of the cross bar while the tool is being passed through the casing, I provide the cutter heads with grooves 4I and the flared ends of the cross head 28 with openings which are adapted for engagement by a strand of wire 4I. The wire is secured and this is sufficient tc hold the cutter heads against the lower end of the spring rod, as well as preventing the cross bar 28 from displacement. As soon as the lower end of, the tool leaves the casing and it is desired to expand the cutters, contact is made with the tool in the usual manner, the impact of which is sufcient to move the rod 2I slightly downwardly which causes automatic release of the detent 36 thereby permitting the cutters to break the strand of wire surrounding the same and to expand into operative position.

A preferred form of means of depressing the rod 2l, which is commonly referred to in field work as a pull down, is illustrated in Figs. 10 and 12 of the drawings. This depressing means or pull down includes a bar 42, which is adapt- Ato ed to be engaged through thel slots 20 of the reamer body and withthe kerf .23 of the spring rod 2l. One of the bars is engaged through a link with one end of. a U-shaped frame 43, the upper end of said frame being engaged with a. recess d4 formed in theupper margin of the bar 42. The U-shaped frame extendsappreciably below the tool and is adaptedto' be engaged by a chain or other suitable means 45 anchored to a support. When the tool is elevated by hoisting means commonly employed in the art, the spring rod is caused to be depressed against the resistance of the spring 35 until the detent 36 locks over one of the shoulders 25 in a manner already described. Following this operation the depressing means or pull down may be disengaged in an apparent manner.

While I have herein described a preferred form of the invention which I have found in actual practice to perform the functions attributed to it, I am nevertheless aware that various changes may be made therein within the scope of the claims herewith appended.

What is claimed is:

1. An underreamer for oil wells including a reamer body equipped with cutters one end of each of which is pivotally mounted in a terminal of the body and movable to project the free ends of the cutters outwardly beyond the plane of the reamer body and completely below the terminal of said body, the Vreamer body engaging ends of the cutters having abrupt shoulders for engagement in complemental recesses formed in the reamer body, said recesses being formed in the body in a plane above the pivotal axes of. the cutters and being disposed on such an inclination from the horizontal as to provide cutter supports in the direction of the normal thrust of the cutters.

2. An underreamer for oil wells including a reamer body equipped with cutters pivotally mounted in the lowest terminal of the body, the cutters being movable to permit expansion of their free ends outwardly at an angle to the body axis, the upper ends of the cutters engaging the lower terminal of the reamer body above the pivotal axes of the cutters in a plane normal to the cutter angle, whereby impact on the latter will be absorbed by the central portion of the reamer body in the direction of the normal thrust.

3. An underreamer for wells including a reamer body equipped with cutters pivotally mounted in its lowest end, the work engaging terminal of each of. which is of substantially inn verted V-shape to provide a pair of obtusely related teeth, said cutters being expansible to disbody, means mounted in said body `for expanding Y the cutters including a spring rod anda cross bar, said cross bar being loosely mounted in the spring rod and cutters and removable therefrom when the cutters are collapsed, the cross bar having end portions so shaped as to automaticallylock the cutters from displacement when in expanded position.

5. An underreamer for wells including a reamer body provided with opposed longitudinal slots, cutters mounted in said body, means mounted in said body for expanding the cutters including a spring rod provided with a slotted head, and means engageable in said slots for depressing said rod'to collapse the cutters including a bar engageable through the' reamer body and in the slotted head and downwardly urged pressure exerting means engaged with the ends of, said bar.

6. An underreamer for wells including a reamer body, cutters pivotally mounted in said body the outer faces of which are grooved, means for expanding the cutters including a spring rod and a cross bar, said cross bar being loosely mounted in the spring rod and cutters and removable therefrom Ywhen the cutters are collapsed, the ends of said bar being perforated in the plane of the cutter grooves, and means engageable through said perforations and with said grooves to prevent displacement of said bar and the cutters when the latter are collapsed.

7. An underreamer for wells including a reamer body provided with opposed longitudinal slots, a pair of cutters pivotally mounted in an end of said body and provided with opposed openings, a spring-pressed rod slidable in said body provided with an opening adjacent the lower end thereof, a bar loosely disposed in said openings of. said cutters and the opening in said rod, a head on the upper end of said rod, and means engageable with said head through said slots to move said cutters to collapsed position.

8. An underreamer for Wells including a reamer body provided with opposed longitudinal slots, a pair of cutters pivotally mounted in an end of said body and provided with opposed openings, a spring-pressed rod slidable in said body provided with an opening adjacent the lower end thereof, a shoulder carried by said rod intermediate the ends thereof, a spring-pressed detent carried by said body and engageable with said shoulder for holding the cutters in collapsed position', and means engageable with said rod through said slots in said body for moving said cutters to Vcollapsed position.

9. An underreamer for wells including a reamer body, a pair of cutters pivotally mounted in an end of said body provided with grooves in the outer surfaces thereof, spring-pressed means carried by said body engaging said cutters for moving said cutters to extended position, and frangible means engageable in said grooves for holding said cutters in collapsed position.

10. VAn underreamer for wells including a reamer body, a pair of cutters pivotally mounted in an end of said body provided with grooves in the outer surfaces thereof, a bar loosely engaging said cutters and disposed transversely of said body, spring-pressed means carried by said body engaging said bar for moving said cutters to extended position, said bar having a notch in each end thereof adapted to aline with the grooves in said cutters, and frangible means engageable in said grooves and said notches for holding said cutters in collapsed position While Vsirrulltaneously holding said bar from lateral movement relative to said cutters when said cutters are in collapsed position.

1l. An underreamer for Wells including a reamer body, cutters pivotally mounted in said body the outer faces of which are grooved, means for expanding the cutters including a spring rod and a cross bar, said cross bar being loosely mounted in the spring rod and cutters and removable therefrom when the cutters are collapsed, the ends of said bar being perforated in the plane of the cutter grooves, and rangible means engageable through said perforations and with said grooves to prevent displacement of said bar and the cutters until the latter are expanded.

12. An underreamer for wells including a reamer body, cutters mounted in said body the outer faces of which cutters are grooved, means carried by said body for expanding the cutters, and frangiblemeans engageable through said rst means and with the cutter grooves to prevent displacement of said first means and cutters until the latter are expanded.

FRED SWAN.