Imaging and depth conversion of low relief fields

Abstract

Abstract A huge proportion of the world’s known hydrocarbon accumulations reside in low-relief structures (see, for example, (Macgregor, 1996)). Capturing top-reservoir undulation for low-relief fields is crucial, impacting reserve calculations and development decisions. We present a workflow and case study of a greenfield development from onshore the Arabian Plate (Sultanate of Oman) where reprocessing and depth conversion velocity model building led to better characterisation of the reservoir and depth uncertainties. With the subtle structural variation captured in two-way-time, time-depth conversions based on direct velocity data allowed the team to make explicit examination of the consequences of the uncertainty to these low-relief reservoirs. In both the reprocessing and depth conversion, horizontal wells played a novel role in the quality control.