| 摘要 |
Method and apparatus for obtaining fine detail of spontaneous potential (SP) along a bore-hole wall in the earth, in connection with exploration for petrochemical deposits. A laterally-extending array (45) of SP-sensing electrodes is mounted on an insulating pad (46), each slightly below the pad surface, and the pad (46) is moved along and against the bore-hole wall while the SP's at the electrodes (45) are sampled and sent to up-hole circuitry for processing. The processed electrode samples are used to form a two-dimensional visually-observable image of the segment of the bore-hole wall swept over by the electrodes on the pad. |
