A case study of azimuthal fracture characterization in Cambay Basin, India

Abstract

Shale gas, shale oil, tight-sand, heavy oil, gas hydrates and CBM are most important unconventional hydrocarbon resources of the 21st century. Tight-sand and shale plays are of low permeability, to exploit hydrocarbon economically, their permeability are increased artificially by creating fractures, which is termed as fracking. Ever widening gap between import and domestic hydrocarbon production in India mandates efficient exploitation of unconventional hydrocarbons. Prevailing hydrocarbon market does not support acquisition of specialized seismic data and specialist software for unconventional hydrocarbon exploitation. It is imperative to devise cost effective way of exploiting tight sand, shale oil and gas. Natural fractures in tight sand and shale plays are helpful in production, its characterization is important. Since seismic amplitude varies along and across swarms of fractures, Multi-Azimuth seismic data can be analyzed for fracture characterization. Onshore seismic data, which are acquired and processed for conventional seismic exploration, can be used in unconventional exploration/exploitation after 5d interpolation of the seismic data in inline, crossline, offset, azimuth and frequency. We analyze seismic amplitude variation with offset and azimuth using conventional seismic data from Cambay Basin, in India for fracture characterization by making the data rich in azimuth by 5d interpolation.