发明名称 |
Method of controlling flow through a drill string using a valve positioned therein |
摘要 |
A downhole valve comprises a tubular body and a valve member. The valve member is normally closed and in the closed position may prevent or restrict passage of a working fluid through the body. The valve member is movable to an open position, a first working fluid pressure differential being necessary to move the valve member from the closed position and a lower second working fluid pressure differential being necessary to maintain the valve member in the open position. |
申请公布号 |
US8069926(B2) |
申请公布日期 |
2011.12.06 |
申请号 |
US20100775716 |
申请日期 |
2010.05.07 |
申请人 |
EDDISON ALAN MARTYN;FARQUHAR HAZEL;ANDERGAUGE LIMITED |
发明人 |
EDDISON ALAN MARTYN;FARQUHAR HAZEL |
分类号 |
E21B34/08;E21B34/06;E21B41/00 |
主分类号 |
E21B34/08 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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