Patent GB-516027-A (GB)
Title: An improved appliance for use in packing off, cementing, repressuring, and other operations in wells
IPC: E21B33/12
Filed: 1938-06-27
Abstract: 516,027. Well appliances. TRIGGS, W. W. (Baker Oil Tools, Inc.). June 27, 1938, No. 18968. [Class 85] A device for use in cementing, repressuring and other operations in wells comprises a hollow body adapted to be detachably secured to a string of running-in tubing, slips mounted on the body, means releasable by hydraulic pressure for retaining some of said slips in ineffective position until so released, and packing means mounted on said body. In Figs. -1, 2 and 7, a body 11 has at its lower end a valve 15 pressed by a spring 19 and initially held open by a shear pin 30 connecting the valve stem to a trunnion 29 depending from a sleeve valve 24 controlling a port 32 and abutting against a stop pin 31. A packer 33 surrounds the body and is held between a lower fixed ring 34 and an upper slidable ring 36 initially held by a shear pin 37. Above the packer 33 is a sleeve 38 provided about its periphery with vertical seats each with two parallel inclined faces on which slips 40, pressed by springs 41, are slidably keyed, alternate slips being adapted for opposite movement to their operative positions; each slip of one set is initially held by a shear pin 42 'and each slip of the other set by two shear pins 43, while the sleeve 38 is held by a shear pin 44. In use, the device is lowered to the desired point, a ball 27 is dropped on to the valve 24 and pressure is built up to depress the valve 24 and open port 32 ; the pressure then expands and elongates the packer as in Fig. 2, shearing the pin 37 and raising the ring 36 to engage alternate slips 40 and break pins 42, the springs 41 then raising these slips to grip the casing and hold the sleeve '38 against downward pressure. The pressure is then relieved and the weight of the tubing 49 is allowed to bear upon the body and break shear pin 44, a flange 50 then engaging the remaining slips and shearing pins 43, springs 41 then lowering these slips to grip the casing and hold sleeve 38 against upward movement. An upward pull is then applied to the tubing 49 to compress the packer 33 as in Fig. 7, a latch ring 46 in the sleeve 38 engaging annular serrations 47 in the body 11 to prevent return of the parts. Higher pressure is then built up in the body 11 to fracture pin 30, and the sleeve valve 24 falls, the valve 15 then being free to seat, and the device is ready for cementing or repressuring operations. If the device is to be used as a bridging plug, a ball 51 is dropped on to a seat 23. In Figs. 8 and 10, a body 11a is provided with a spring-pressed valve 15a hinged at 15b and initially held open by a lug 28a on a sleeve 24a held by a shear pin 30a. A packer 33a surrounds the body and is connected to lower and upper cones 34a, 36a, shear pins 37a initially holding the cones, a larger number of such pins being provided with the cone 34a. Slips 1a, 2a, co-operate with the cones 36a, 34a, and are initially secured to the cones and body respectively by shear pins 37c, 37d. In use, after dropping a ball into'sleeve 24a, pressure is built up and acts through ports 32a to expand and elongate the packer 33a as in Fig. 2, thus shearing the upper pins 37a, raising the cone 36a and shearing the upper pins 37a, 37d, the upper slips la expanding to engage the casing after contacting a flange 50a. Pressure is then relieved and an upward pull is then applied to the tubing 49a to first compress the packer 33a as in Fig. 10, and then shear pins 37a, 37c and 37d so that a shoulder 53a may expand the slips 2a; a latch ring 46a in the cone 36a then engages annular serrations 47a to prevent return of the ports. Higher pressure is then built up to shear pin 30a and the sleeve 24a falls to free the valve 15a for seating.