| 摘要 |
PCT No. PCT/GB92/01351 Sec. 371 Date Mar. 25, 1994 Sec. 102(e) Date Mar. 25, 1994 PCT Filed Jul. 23, 1992 PCT Pub. No. WO/9303255 PCT Pub. Date Feb. 18, 1993.A tubing test valve (34, 34a) is described for use with a drill string (20) for pressure testing tubulars and downhole equipment, particularly in a cased hole (12) which has a permanent packer (16) fitted. The valve (34) permits self-filling during running-in, but allows pressure testing when stationary in the well (1). The valve (34) also permits multiple entry of the string to, and retrieval from, permanent packers without committing the tool to the locked open position. This is achieved by providing an apertured ball valve (50, 50a) in the tool housing (42, 42a) which can be moved axially and rotated with the bore (70A, 71A) of the housing (42, 42a). The ball valve has side orifices (54, 54a) and a top orifice (52a) which controls flow through the valve (34, 34a). In one embodiment the ball element (50) is suspended by coil spring (64) above the lower valve seat (56) during running-in and is closed for pressure testing by pressuring with fluid from above. In another embodiment the ball element (50a) is biased by a spring (66a) into engagement with the valve seat (56a) when stationary to allow pressure testing during running as the flow of fluid lifts the ball (50a) off its seat (56a) to allow self-filling. In both embodiments the ball element (50, 50a) contains slots (58, 58a) mounted on pins (62, 62a) which allow the ball to be rotated when the tool is in the packer (16) when engaging the valve seat (56, 56a) to break the seal and allow pressure in the bore above (71A) and below (70A) the ball element (50, 50a) to equalise. This allows the tool to be withdrawn from the packer (16). |
