BOTTOM HOLE SHUT-IN TOOL

摘要

A bottom hole shut-in tool incorporating a ball and seat shut-off valve and a ball and seat pressure equalizing valve. The ball elements of the valves are formed of elastomeric material, which allows the ball elements to engage their seats in continuous annular sealing contact even when debris from the well is trapped between a ball and its seat or when a ball is not exactly aligned with its seat. This arrangement effectively seals off the pressure gauge used in conducting a pressure survey from fluid in the well tubing located above the shut-off valve.