| 摘要 |
The distance from a borehole (24) to a nearby target well (14) is determined by positioning a magnetic sensor (40) in the borehole (24) at a known depth and providing a magnetic source (50) in the target well (14) and by moving the source (50) to depths above and below the depth of the sensor (40) and detecting maximum field vectors. The distance the source (50) moves between the maxima is the distance between the wells. In another embodiment, the ratio of source magnetic field vectors is used to determine the ratio of the difference in depth z between the source (50) and the sensor (40) to the lateral distance r between the wells. This ratio z/r is then used to determine the separation of the wells. |
