Estimating anisotropy parameter by shear wave splitting of crosswell seismic data: a case study on inter-bedded sand-shale layers

Abstract

This paper describes a method to determine anisotropy parameter by shear wave splitting of crosswell seismic data. The purpose of this work is to present a section of anisotropy to be used in detecting hydrocarbon. Splitted S-waves were detected by picking the traveltimes of S-fast and S-slow on SH and SV components, respectively. Polarization method was done on the 3-C crosswell data using hodogram analysis, so that from these three components we can observe P-, SH- and SV-waves. Tomography of SH- and SV-wave of crosswell seismic were run to produce SH and SV tomograms. Due to the azimuth randomness of the 3-C receivers, an azimuth and inclination correction were implemented on the data, and some preconditioning were applied to enhance the quality of the firstbreaks including deconvolution, bandpass filtering and fx-decon. The traveltimes were picked on SH and SV components, furthermore to be inversed using traveltime tomography algorithm. In this work, a case study was carried out to the seismic data collected on inter-bedded sand-shale layers. The results of this work are SH- and SV-wave tomograms and the anisotropy section. We conclude that this method is effectively presenting an anisotropy section to be used for reservoir recognition.