Joint Migration Inversion of 3D Full Wavefield Borehole Data

Abstract

3D borehole-related seismic data can provide us with accurate velocity models and high-resolution images. However, conventional imaging algorithms that assume primary reflection energy will cover only a limited areaaround the borehole. This illumination problem can be overcome by including surface-related and internal multiples in the imaging algorithm to enhance the illumination of the subsurface and image areas that are beyond the coverage of primary reflections. The industry standard for 3D borehole imaging is to use the first breaks to update the velocity model and consider only the primary reflections for imaging. It has been demonstrated that multiple scattering and the down-going wavefield can tremendously extend the imaging area around the borehole. Moreover, primary and multiple scattering contain valuable and crucial information that
can enable us to update the velocity model beyond the coverage area of the first arrivals. In this paper we have employed the full wavefield of the 3D borehole data - containing all order scattering in both up/ down-going wavefields - in one integrated inversion-imaging process as proposed by the joint migration inversion methodology. The final result is a smooth accurate background velocity model along with a true amplitude reflectivity high-resolution image with and maximum lateral extent.