Method and apparatus for multipole acoustic logging

摘要: Apparatus for shear wave borehole logging has a source section 30, spacer 32, detector 34 and coupling 36, adjacent sections being linked by isolation joints 38. The 30 slotted steel housing 48 containing 42 with two transducers 44a/44b 44c/44d each arranged to produce acoustic radiation dipole pattern. are oriented so that their patterns transverse one another the axis. also 80 contains six detectors 82 84a/84b 84c/84d similarly transducers. joint 38 between comprises lengths of wire 76 secured at end sonde bridging gap sections. In use is energized in turn as apparatus drawn up borehole, waveforms signals received twelve digitized recorded. Various analyses recordings enable formation slowness be derived, even `slow` formations, permit information obtained regarding magnitude orientation anisotropy formation.