GB1443085A - Oil well testing apparatus - Google Patents

Abstract

1443085 Wells &c HALLIBURTON CO 21 Feb 1974 [13 March 1973] 8027/74 Heading E1F A formation tester 1 insertable in a pipe string (not shown) and having a through-bore 111 comprises a housing 200, a mandrel 112 reciprocable in the housing, and a valve 5 opened and closed by reciprocation of the mandrel. The upper part 2 of the housing is connected to the upper part of the string and the lower part 151 of the mandrel is connected to the lower part of the string which includes a packer. The tester with the valve closed as shown is run into the well on the string, well fluids passing through holes 28 (Fig. 1c) and acting on surfaces 68, 69 of an upper mandrel 56 detachably fixed to the housing by spring fingers 67. Well fluids also pass through holes 141 (Fig. 1e) to act on one side of a piston 137, the other side of which is acted upon by a charge of fluid in a chamber 136. At the test depth the packer is set and the valve is opened by setting down on the string, compressing a spring 155 and moving the mandrel 112 further into the housing, lugs 148 carried by the mandrel 112 moving from positions A to B in a cam slot in a sleeve 101 (Fig. 9) forming part of the housing. The rate of movement of the mandrel is governed by the rate of discharge of a fluid charge from a chamber 158 through an adjustable annulus. As the mandrel 112 moves into the housing a groove 105 (Fig. 1c) moves opposite to the ends 76 of the spring fingers to free the upper mandrel 56 from the housing to permit the mandrel 56 to be moved by the mandrel 112. When the mandrels have moved sufficiently for the ports 63 in the mandrel 56 to pass a seal 37, the hydraulic pressure in the tester below the valve is reduced to reduce pressure on the bottom of a collar 7 and hence on the valve. As the mandrels move further the mandrel 56 engages pins 14 (Fig. 1b) to raise a sleeve 11 which carries with it members 6 having pins 61. As the pins move they rotate the valve to the open position. When the valve is partially open the outflow from the chamber 158 is no longer restricted and the final opening of the valve is rapid so that an indication is given at the surface. The valve remains open all the while there is a weight on the string. When the tester is to be closed the. string is picked up and then released, the lug moving to the position C and then to the position D where the valve is locked closed. The string may be picked-up to move the lug to the position A' in readiness for opening the valve by setting down the string. The slotted sleeve 101 and lug may be dispensed with.