| 摘要 |
Formation density is calculated from acoustic logging measurements. This technique does not require a radioactive source and in fact it may offer better precision particularly in rugose boreholes. In at least some embodiments, the technique exploits an observed relationship between a transmission coefficient T(p b , V c ,p m V m ) and a breakdown resistance µB(p b , V c ,V s ) to enable determination of the formation density pb from measurements of the formation's compressional wave velocity V c , the formation's shear wave velocity Vs, and the borehole fluid's acoustic impedance p m V m . The desired measurements can be acquired by attaching or integrating a fluid cell with an acoustic logging tool that measures acoustic wave propagation velocities. Real-time density logs can be obtained from both wireline and logging- while-drilling implementations. |
