Patent GB-626101-A (GB)
Title: Improvements relating to the cutting of pipes in wells
IPC: E21B43/114
Filed: 1947-04-09
Abstract: 626,101. Cutting pipes in weils by abrasive liquid. NAAMLOOZE VENNOOTSCHAP DE BATAAFSCHE PETROLEUM MAATSCHAPPIJ. April 9,1947, No. 9427. Convention date, April 15, 1946. [Class 60] Apparatus for cutting a pipe in a well includes a nozzle unit, anchoring means for anchoring the nozzle unit at a desired position in the pipe, sealing means for sealing the space between the device and the pipe above the nozzle unit, and fluid passageways for causing abrasive liquid pumped down the pipe to issue through the nozzle unit to cut the pipe. An inner member 25, Fig. 1, is provided at its top with a cage 13 connected therewith by a screw threaded or welded flange 17, the cage having hooks for engagement by a setting device. The lower end of member 25 carries, by a screw threaded spider 37, a rod 39 to the lower end of which is secured, by a spider 51, a member 49 provided with a non-return valve 55. A member 41 is rotatably mounted between the lower end of member 25 and the member 49, bearings 43, 47 and packings 40,48 being provided. The member 41 has a number of eccentrically located jet nozzles 45. A sleeve 23 surrounds the upper part of the inner member 25, a step 19 on the upper face of the sleeve being normally engaged by fingers 9b pivoted on the cage 13. A spring 27 is located between the lower end of the sleeve 23 and the lower end 29 of a housing 11; shoes 33 connected by links 31 to the part 29 slide on inclined ways 38 on the part 25. The spring 27 is compressed by moving the housing 11 upwardly relatively to the sleeve 23, and a shear pin 22 is inserted. The upper end of the housing 11 carries a packing 8 and a part 3 for engagement by a retrieving member. The device is lowered into the pipe to be cut by means of a setting device comprising two parts 63, 65 having limited relative axial movement. The part 63 can be attached at 61 to a cable etc.; the part 65 has pivoted hooks 77 which engage the hooks on the cage 13. When the lowering means is suddenly braked, the inertia of the housing 11 causes it to continue moving downwardly, whereby the pin 22 is sheared and the spring 27 expands, so that the shoes 33 are forced downwardly and outwardly to grip the pipe. On further lowering of the setting device, a pin 67 on the upper member 63 causes the hooks 77 to be moved together to disengage the hooks on the cage 13 and the setting device can then be drawn up the pipe. Liquids mud to which additional abrasive may be added is now pumped down the pipe and passes through the jets 45, the member 41 being rotated by reaction. The liquid expands the packing 8 against the wall of the pipe to exclude liquid from the annulus between the device and the pipe. The valve 55 permits the passage of liquid up through the device while it is being lowered into the pipe; the valve closes when the abrasive liquid is pumped down the pipe. When the cut has been made, the upper section of pipe may be removed with the device still clamped therein. When it is not desired to remove the pipe, a retrieving device, Fig. 5, is lowered into the pipe; the bevel 95 thereon engages the upper ends 9a of the levers pivoted on the cage 13 so that the fingers 9b are disengaged from the step 19 on the sleeve 23; fingers 9 on the retrieving device engage the part 3 of the housing 11, whereby the device can be lifted from the pipe; liquid can pass through ports 28a and 28 which register because of the relative upward movement of the sleeve 23.