US3024842A

US3024842A - Device for cutting bore hole pipes

Info

Publication number: US3024842A
Application number: US758942A
Authority: US
Inventors: Ringler Maurycy
Original assignee: Individual
Current assignee: Individual
Priority date: 1958-02-04
Filing date: 1958-09-04
Publication date: 1962-03-13
Anticipated expiration: 1979-03-13

Description

March 1952 M. RINGLER 3,024,842

DEVICE FOR CUTTING BORE HOLE PIPES Filed Sept. 4, 1958 Fig.1 Fig.2 F495 INVENTOR. /7/; UR rc r Ewe/.5?

BY Mi 9. [A

3,024,842 Patented Mar. 13, 1962 3,024,842 DEVICE FOR CUTTING BORE HOLE PIPES Maurycy Ringler, 3 Beth Oren St., Yad Eliahu, Tel Aviv, Israel Filed Sept. 4, 1958, Ser. No. 758,942 Claims priority, application Israel Feb. 4, 1958 4 Claims. (Cl. 166-55.6)

In sinking a Well the drill is positioned at the end of a shaft constituted by steel tubing. As the drilling proceeds pipes are successively lowered into the bore hole lining the latter. Thus the said hollow shaft extends within a pipe casing reaching down into the bore hole.

It sometimes happens that for one reason or another the hollow shaft (the drill pipes) or the drill collar has to be cut off so as to retrieve it from the bore hole. For this purpose cutters are used of more or less complicated design. Such cutters have to be lowered through the narrow annular space between the said shaft and the casing and are therefore as thin walled as possible. That necessity imposes limitations on the designer and that is the reason why such cutters are not entirely satisfactory. Their main disadvantage is that they can cut through thin walled drill pipes up to, say, 12 mm. only so that they cannot sever a so called drill collar with a Wall thickness of, say, 45 mm. For such reason it may even happen that a bore hole has to be abandoned.

It is the object of the present invention to provide a cutter of novel construction, and more specifically one which can be used for cutting drill collars.

It is another object of the invention to provide a cutter of simple construction which can easily be lowered in the bore hole to its eventual position of work.

These and other objects of the invention will become clear from the following detailed description with reference to the annexed drawings showing in FIGURE 1 the new cutter in an elevation, partly in section. FIG- URE 2 is an axial sectional view of the new cutter. FIGURE 3 is a like view of the cutter in position on a hollow shaft and during the cutting operation, FIGURES 4, 5, and 6 are horizontal sections along lines IV-IV, VV, VI-VI of FIGURES l, 2, 3 respectively. FIG. 7 shows a front elevation of a milling cutter.

FIG. 8 shows a side elevation of the same, partly in section, as seen in the direction of arrow VIII of FIG. 7.

FIG. 9 is a section of the milling cutter along line IX--IX of FIG. 8.

A sleeve 1 is provided at its lower end with a set of circumferential teeth 10. The sleeve will 'have a diameter suitable for the diameter of the bore hole and that of the drill pipes or drill collar. In the wall of sleeve 1 there are provided two pairs of diametrically opposed cut-outs or openings 35 in which are articulated by means of pins 2 downwardly extending arms 3 which at their lower ends carry

milling cutters

33 and 34. The arms and cutters are of such crosswise dimension that they can be accommodated within the thickness of the wall of the sleeve. In the example shown four such cutters are provided, evenly distributed around the circumference of the sleeve, two cutters 33 reaching slightly lower down than the two other cutters 34. The cutters on their arms 3 swing in said openings 35. Flat springs 4 are fixed at the lowermost edge of openings 35 flush with the outside of sleeve 1 and urging arms 3 inwardly.

At its upper end sleeve 1 has an internal screw thread 5 so that in the conventional way the sleeve can be lowered into the bore hole at the end of a piece of pipe 8, to the upper end of which another pipe is screwed and so on to be finally fixed to a drive for rotating. Near the lower end of sleeve 1 two pairs of detents 12 are provided adapted to lie flat at the inner face of sleeve 1 and urged by springs 13 or by their own weight into horizontal position so as to lie athwart the interior of the sleeve. Within sleeve 1 a short piece of tube 11 is slidably supported for a purpose yet to be described.

When it is desired to retrieve a shaft from a bore hole and to cut 01? the shaft or a fouled drill the sleeve 1 is slipped, at the mouth of the bore hole, over the upper end of the shaft. At that instant the short piece 11 being in slidable frictional fit within sleeve 1 holds the cutters in their position fiush with the sleeve wall. When sleeve 1 is slipped downwardly member 11 will be pushed out by the edge of the hollow shaft but still the cutters, though under the urge of springs 4, cannot snap inwardly but will lie within the wall of sleeve 1 and abut against the outside of the hollow shaft 14. On its way down the sleeve 1 will cut through incidentally accumulated hindrances, for which purpose the teeth 10 are provided. When the tool has arrived at the position where it is to cut, the cutters 33 will be in position on the shaft 14 and so will be the cutters 34 but at a slightly higher level. The cutting operation can now be started by rotating sleeve 1 about its axis. All four milling cutters will start milling a groove into the wall of the hollow shaft 14. Cutters 34 mill a groove to a certain depth and then their arms 3 will apply themselves to the edge of the milled groove and no further deepening of the cut will be obtained by these cutters. However, the groove cut by cutters 34 will permit the Working face of cutters 33 to penetrate deep enough to cut through the wall without arm 3 striking against the edge of the groove and preventing further penetration. This is so because the edge of the groove cut by cutters 33 has previously been removed by cutters 34 (see FIGURE 3). When cutters 33 have cut fully through the wall of the shaft and severed it above the drill it is possible to retrieve the shaft. This is done by pulling up sleeve 1. Detents 12 urged inwardly by springs 13,, will then engage under the cut edge and will pull up the whole shaft together with the upwardly moving tool. If necessary, the operation may be repeated i.e. a drill collar may be cut into several pieces which may be lifted one after another. Cutting of a drill collar will take up to four hours with 40-45 r.p.m. Cooling of the cutter may be performed by mud or water circulation as known per so.

What I claim is:

1. Apparatus for cutting drill collars and drill pipes in bore holes comprising, in combination, a sleeve having means for connection to rotational drive means, said sleeve having a longitudinal axial bore slidably receiving a hollow drill shaft therewithin, said sleeve having wall portions defining a plurality of circumferentially spaced apart cutouts, at least two pairs of milling cutters having working faces facing inwardly of said bore, each of said milling cutters being articulated within said cutouts, one pair of said cutters having said working faces at a higher level than the level of the remaining milling cutters and being adapted to cut a groove which overlaps the groove cut by said remaining milling cutters, and spring means yieldably urging said cutters radially inwardly of said longitudinal bore of said sleeve.

2. Apparatus for cutting drill collars and drill pipes in bore holes as claimed in claim 1, wherein the lower edge of the sleeve is provided With teeth.

3. Apparatus for cutting drill collars and drill pipes as claimed in claim 1, further comprising detents supported adjacent to the lower edge of the sleeve urged into horizontal position to lie athwart the interior of the sleeve.

4. Apparatus for cutting drill collars and drill pipes as claimed in claim 1, further comprising a short piece of tube of an outside diameter substantially equal to the inside diameter of the sleeve and adapted to be inserted into the sleeve to retain the cutters in retractable position.

References Cited in the file of this patent UNITED STATES PATENTS