首页>
外国专利>
WELL ANNULUS PRESSURE CHANGE OPERATED VALVE:PRESSURE CHANGE ON ONE SIDE OF ACTUATING PISTON REDUCED BY FLOATING SHOE SEAL FRICTION
WELL ANNULUS PRESSURE CHANGE OPERATED VALVE:PRESSURE CHANGE ON ONE SIDE OF ACTUATING PISTON REDUCED BY FLOATING SHOE SEAL FRICTION
展开▼
机译:良好的环形压力变化控制阀:通过浮动鞋底摩擦力来减小致动活塞一侧的压力变化
展开▼
页面导航
摘要
著录项
相似文献
摘要
An annulus pressure responsive downhole tool includes a housing having a power piston slidably disposed therein. First and second pressure conducting passages communicate a well annulus with first and second sides of the power piston. A retarding device is disposed in the second pressure conducting passage for delaying communication of a sufficient portion of an increase in well annulus pressure to the second side of the power piston for a sufficient time to allow a pressure differential across the power piston to move the power piston from a first position to a second position relative to the housing. The retarding device is an annular floating shoe having a large number of O-rings frictionally engaging inner and outer tubular members of said housing. A pressure relief valve is communicated with the second pressure conducting passage between the power piston and the retarding device for relieving from the second pressure conducting passage a volume of fluid sufficient to permit the power piston to travel to its second position. A spring biased pin disposed in the housing engages an indentation in an actuating mandrel attached to said power piston to releasably hold the power piston in its second position.
展开▼