发明名称 |
Method and apparatus for drilling boreholes in earth formations (drills in liner systems) |
摘要 |
A method of sinking a bore hole in underground formations which have at least one special stratiform formation which features vastly differing formation pressures in respect to a formation adjacent to it in the sinking direction and in which a drilling tool carried at the bottom end of a drill line and having a drill bit driven by a deep drilling motor drills out a first part of a bore hole which extends to a point close to the boundary area of the special formation, characterized in that upon subsequent sinking of a further part of the bore hole by the casing string which passes through at least one special formation, a tubular outer casing with a bottom end carrying a driven drill head is entrained, the bore hole being lined by this, at least in the region of the special formation.
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申请公布号 |
US5845722(A) |
申请公布日期 |
1998.12.08 |
申请号 |
US19960729226 |
申请日期 |
1996.10.09 |
申请人 |
BAKER HUGHES INCORPORATED |
发明人 |
MAKOHL, FRIEDHEIM;VOGT, CARSTEN;PUDJIHANTO, SURWANO |
分类号 |
E21B7/20;(IPC1-7):E21B7/20 |
主分类号 |
E21B7/20 |
代理机构 |
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代理人 |
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地址 |
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