METHOD FOR ENCHANCING RESOLUTION OF ELASTIC WAVE VELOCITIES BY ISOLATING A WAVE EVENT IN LITHOGRAPHIC FORMATION

摘要

Acoustic logging data are obtained using a logging tool including at least o n transmitter and a plurality of receivers (101). A wave form matching inversi on is performed to obtain formation slowness profiles at various resolutions ranging from the total length of the receiver array to the inter-array receiver spacing (105). Using overlapping sub-arrays of reduced aperture provides for resolution enhancement. The enhancement is achieved by minimizi ng the noise contamination effects by maximizing the information redundancy in wave form data (109). The method achieves this by isolating the wave event o f interest and matching the wave form of the event for all possible receiver pairs allowed by the sub-array (111). The high-resolution slowness curve successfully resolves the laminated features in a geological formation (115) . This invention is a useful tool for evaluating thin beds in laminated formations using bore hole acoustic logging.