Fault Plane Geomorphology and Structural Analysis of a Middle Eastern Giant Carbonate Oil Field

Abstract

The characterization of geomorphic features such as fault plane geometries and slickensides can reveal intricacies of fault displacement as well as the forces that formed the fault. Fault plane geomorphologic features such as grooves, ridges, and steps, which are normally observed in outcrops, are apparently scale independent and can be extracted by detailed fault interpretation on 3D seismic data.

The Middle East has generally focused its production on conventional structural plays. Therefore, the advancement of new structural interpretation techniques is essential to the longevity and expansion of producing fields as well as the development potential of yet untapped reservoirs. This study uses fault plane geomorphology and slickensides to reveal strain regime, fault mechanical stratigraphy and fault movement for faults that have had more than one episode. This study focuses on an orthogonal faults system that consists of a strike-slip fault complex as well a high angle reverse fault. Using geomorphic features, this study reveals the strain regime and structural history behind the formation of the complex system of faults. The techniques established in this study provide an example for the identification and analysis of large scale slickensides in 3D seismic data to form a comprehensive understanding of local structures.

The structural and fault plane geomorphic analysis reveals that the orthogonal fault system formed in the late Jurassic, likely the late Kimmeridgian to early Tithonian, as a strike-slip system developed from a ductile shear zone which involved the development of Riedel shears. The aggressive compressional event of the late Cretaceous reactivated the previously developed R' shear plane with a newly imprinted compressional component making it a reverse fault that extended up through stratigraphy of the Cretaceous.

AAPG Datapages/Search and Discovery Article #90219 © 2015 GCAGS, Houston, Texas, September 20-22, 2015