| 摘要 |
A contact subassembly on a downhole carrier is moved by torsion rod, rotation of which moves the contact assembly to the proximity of the borehole wall. Rotation of the torsion rod may be accomplished by a hydraulically powered piston-lever arrangement. The rotation of the torsion bar may be used to estimate the borehole size. The contact assembly may be provided with resistivity sensors, acoustic sensor for making VSP measurements while drilling, and a port for sampling a formation fluid. |
