A METHOD OF PRODUCING AND UTILISING HIGH RESOLUTION IMPEDANCE LOGS DERIVED FROM VSP DATA FOR USE IN ASSESSING AN OILFIELD SUBTERRANEAN FORMATION

摘要

The invention relates to a method of producing and utilising high resolution impedance logs derived from Vertical Seismic Profile (VSP) data. The resulting logs are for use in assessing an oilfield subterranean formation. The method includes obtaining appropriate VSP data, generating a VSP Derived Impedance Log (VDIL) from said VSP data, inputting the VDIL impedance values to an initial rock model to determine or refine the dry rock frame modulus, modifying the impedance values of the VDIL to represent one or more postulated changes in particular properties of the rock or its fluid content to create a modified VDIL, and generating a modified Synthetic Seismogram from the modified VDIL.