Improved Geobody Characterization in the Supergiant Kashagan Carbonate Reservoir Through the Use of Diffraction Imaging

Abstract

Abstract Kashagan is a Devonian-Carboniferous age isolated carbonate buildup located in the Pre-Caspian Basin of Kazakhstan. Geomorphologically the field is divided into two regions: platform and rim. The platform is characterized by grainstones with good matrix porosity and wells in this location tend to be good producers. In contrast, the rim consists mainly of boundstones with very poor matrix porosities and wells drilled in these regions target non-matrix features, such as karsts and fractures. Identification of these non-matrix features, collectively known as geobodies, play an important role in the in-place resource volumes, permeability architecture, and overall reservoir performance of the supergiant offshore Kashagan oil field. Many of the rim wells that successfully target a geobody result in the highest production rates within the entire field. Thus, the accurate and precise imaging of geobodies has always been essential task for the operator of the field. Many different seismic attributes and processing techniques have been attempted in order to aid in the identification of geobodies. This paper discusses the use of diffraction imaging and the analysis of the resulting data volumes to improve the imaging and confidence in the location of non-matrix features within the Kashagan carbonate reservoir.