SUSPENDED TUBULAR FORMATION TESTER FOR EXAMINING OIL AND GAS WELLS DURING DRILLING PROCESS Russian patent published in 1997 - IPC

FIELD: oil and gas production. SUBSTANCE: when testing open oil and gas holes with tubular formation testers, packer operates as piston in borehole-cylinder transmitting axial force from pressure drop, which it holds, to tail or anchor. Owing to primary axial compressing loading, rubber of packer expands to borehole diameter. Compressed rubber gasket tightly abut walls of borehole and drilling mud, upon vertical up-and-down displacement of device, overflows through corresponding valves inside device. Inlet valve is coupled with upper overflow valve and is held closed by shear pin. Back valve is coupled with lower overflow valve and allows drilling mud to flow only in upward direction when device moves downwards. When device is raised higher than 2 m, inlet valve, experiencing pressure drop on rubber gasket, opens cutting the pin, which results in closing of upper overflow valve. EFFECT: facilitated testing oil and gas wells. 6 dwg