Delineation of Fracture Clusters by Integrating Tectonic Events, Seismic Attributes, BHI Interpretation, Mud Losses during Drilling and Well Test Data – A Case Study in a Carbonate Reservoir, Offshore Abu Dhabi

Abstract

Faults and fractures play an important role in reservoir production, since they can act either as barriers or conduits for fluid migration. They are also one of the key factors to be considered for drilling trajectory design. However, it is very challenging to delineate fractures due to the limitation of seismic resolution. The objective of this study was to conduct fracture cluster characterization for one of the carbonate reservoirs in Abu Dhabi, using a recently acquired 3D seismic survey. In this study, the similar workflow used by Singh et al. (2009) was followed. First of all, structural evolution and regional paleo including current principal stress orientations were investigated. Three major tectonic events were identified, and they are the main contributors to the development of faults and related fractures. Secondly, seismic data was processed based on an objective-driven processing sequence. Three fracture volumes were generated and five sets of fractures were interpreted. They were validated against the regional principal stress orientations, BHI interpretation, mud losses and well test data. In addition, previously the discontinuities along NNE-SSW direction in the area of interest were considered as seismic acquisition footprints. Through this study, it was proved that those discontinuities are small scale faults, hereby enhanced the existing reservoir characterization. The findings on faults and fractures characterization in the study area are critical in field development plan and drilling efficiency. This study showed that integrating data from different disciplines is a reliable and effective way to delineate fracture clusters.