Fracture Characterization at Clair - Analysis of P-Wave Azimuthal Anisotropy in 2D 3D Ocean-Bottom Data

摘要

Over the past ten years, there has been a continuous increase in the use of 3D P-wave data for fracture characterization. In this study, we analyze P-wave azimuthal anisotropy in three 2D OBC (Ocean-Bottom-Cable) lines combined with a patch of 3D OBC data from the Clair Field, in the UK continental shelf (UKCS), in order to assess how seismic anisotropy can help improving fracture characterization in this field. The three 2D OBC lines are at 45-degree angle with each other, intersecting at a well position, and overlaps with the 3D survey. Analysis of the P-wave amplitude and velocity at the intersecting point shows significant azimuthal variation. P-wave interval velocities show about 10% variation in azimuth and the orientation is at N94oE, agreeing with previous studies. The 2D and 3D results are consistent at the intersecting point, and the joint analysis of 2D and 3D data increases the spatial coverage and improves the accuracy, further confirming the potential for using azimuthal variations of P-wave attributes for fracture detection.