| 摘要 |
<p>A multi-mode testing tool operable as a drill pipe tester, formation tester, nitrogen displacement valve or circulation valve, comprises a housing defining a longitudinal bore (370), and valve means (330) operable in at least a circulation valve mode and a displacement valve mode. An operating means (260) is provided to change the valve means between valve modes responsive to changes in pressure near the tool in the well bore, the operating means including a fluid filled chamber (210), a pressure responsive double-acting piston means (168,190,192), two longitudinally spaced piston stop means (127,146), and a ball and slot ratchet means (164,186).</p> |
