Abstract: 3D Seismic Integrated study of MRSI: A Multi - Reservoir Salt Induced Structure, Offshore Abu Dhabi

TACHET DES COMBES, J., D.CHENOT, C. JAVAUX, K. BELAID, and T. H. HASSAN

A multidisciplinary approach involving geology, geophysics and petrophysics was used to assess the MRSI structure. Being a multi-reservoir and a salt induced structure, it is thus quite unique in the offshore Abu Dhabi. Wells have proven the presence of hydrocarbons in four different reservoirs, namely in the Gachsaran, the Asmari, the Halul and the Shuaiba formations. The main topics addressed in this paper will be:

Methodology for structure appraisal.

Integration of geological and geophysical data for reservoir evaluation.

The structural definition of this complex accumulation was provided by a recent set of 3D seismic data. The seismic interpretation was workstation-based with the help of 3D visualization tools. They combined the seismic data together with the horizons or seismic attributes and the interpreted faults. They enabled access to a sophisticated representation of the structure. MRSI was confirmed as a high-relief salt-induced feature with associated fault pattern. These techniques allowed one to reduce the uncertainties on the structural appraisal of MRSI.

A sequence stratigraphic framework was built using seismic data combined with lithofacies and depositional environments, as well as diagenetic process studies. Based on geological and petrophysical data, a tentative rock type scheme was developed as a basis for reservoir characterization. These results were then input into a 3D geologic model and used to run the volumetrics and estimate its associated uncertainties.

The integration of all the different disciplines will help optimize future drilling and lead to a more efficient appraisal of the MRSI structure.

AAPG Search and Discovery Article #90942©1997 AAPG International Conference and Exhibition, Vienna, Austria