发明名称 |
Nuclear magnetic resonance logging with azimuthal resolution using gradient coils |
摘要 |
The present invention relates generally to an apparatus and method for obtaining an azimuthally resolved nuclear magnetic resonance measurement of an earth formation traversed by a borehole. The measurement can be made while drilling or using a wireline tool. At least one gradient coil is positioned circumferentially round the tool. A magnetic field is produced by the coil in a region of the formation facing the coil. The magnetic field is substantially parallel to the static magnetic field produced by a pair of permanent magnets which form a part of the tool. The additional field causes an additional phase shift for spins located in the region so that the spins subjected to the additional field do not form a spin-echo. <IMAGE> |
申请公布号 |
AU3687499(A) |
申请公布日期 |
2000.02.24 |
申请号 |
AU19990036874 |
申请日期 |
1999.06.29 |
申请人 |
SCHLUMBERGER HOLDINGS LIMITED |
发明人 |
KRISHNAMURTHY GANESAN;PETER SPEIER;BRUNO LUONG;RALF HEIDLER;STEVEN F CRARY |
分类号 |
G01R33/385;G01R33/44;G01V3/32 |
主分类号 |
G01R33/385 |
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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