Cracking the Valuable Insights & Caveats in Practical Extended Elastic Impedance (EEI). Case Example from Balingian Sarawak

The utilization of Extended Elastic Impedance (EEI) proves to be a rapid and accessible method for gaining insights into lithology, fairway determination, and reservoir properties, with some indications towards hydrocarbon fluid assessment. However, seismic EEI encounters challenges in terms of uncertainty and reliability, primarily stemming from poor calibration to well data. In the well feasibility study stage, the EEI-transformed property, utilizing raw recorded logs as input, consistently exhibits a wide ranges of Chi angles for different wells. Consequently, the technology is often criticized as unreliable and deemed unsuitable for deployment. This study addresses the critical role of well data pre-conditioning as a prerequisite for successful EEI applications. Four recently acquired wells within close proximity, each equipped with complete elastic logs (density, p-sonic, and s-sonic), are examined in this study. The designated area features water depths ranging from 500 to 1600 meters, predominantly characterized by clastic sediment composed of clay and quartz minerals.