Subsurface safety valves and method and apparatus for their operation

摘要

Method and apparatus for pressurizing the top of the valve member of a subsurface safety to equalized pressure thereacross and assist in opening the valve. The apparatus includes a chamber filled with fluid under pressure which is admitted in to the space between the apparatus and a valve when landed in the valve to pressurized the valve. A spring loaded prong on the apparatus urges the valve member of the safety valve to open position. A latch is included which will bypass a top landing nipple and land in a second landing nipple. The subsurface safety valve is provided with means for filling its spring chamber with liquid with the valve closed. When the safety valve is open the spring chamber is isolated to protect the chamber from flow of fluids and solids.