초록 ▼

In accordance with an illustrative embodiment of the present invention, a pressure controlled well tester apparatus having a full-bore ball valve closure element includes valve actuator means responsive to changes in the pressure of fluids in the well annulus for moving the ball valve between its op

In accordance with an illustrative embodiment of the present invention, a pressure controlled well tester apparatus having a full-bore ball valve closure element includes valve actuator means responsive to changes in the pressure of fluids in the well annulus for moving the ball valve between its open and closed positions, and bias means responsive to the hydrostatic pressure of fluids in the well bore for assisting in moving the ball valve to its fully closed position.

대표청구항 ▼

A fluid pressure controlled well tester apparatus comprising: housing means adapted for connection to a pipe string and having a flow passage extending therethrough for conducting formation fluids from an isolated formation interval; full-opening valve means for opening and closing said flow passage

A fluid pressure controlled well tester apparatus comprising: housing means adapted for connection to a pipe string and having a flow passage extending therethrough for conducting formation fluids from an isolated formation interval; full-opening valve means for opening and closing said flow passage; a stepped-diameter mandrel that is longitudinally movable and sealingly slidable within said housing means; first seal means between a lesser diameter portion of said mandrel and said housing means and second seal means between a greater diameter portion of said mandrel and said housing means, said first and second seal means being arranged to define an atmospheric chamber for maintaining a quantity of gas at less than the annulus hydrostatic head pressure; and means subjecting a transverse cross-sectional area of said mandrel to changes in the pressure of fluids in the well annulus for moving said mandrel to shift said valve means between closed and open positions in such manner that movement of said mandrel to the valve open position will cause expansion of said atmospheric chamber to bias the mandrel in the valve closed position.