Abstract: Structural analysis of faults, fractures and in-situ stress, and their role in controlling reservoir dynamics of an onshore field, Abu Dhabi, UAE
EL-SHAZLY, SALAH, S. AL-MATROUSHI, N. YOUNG, and M. AKBAR
Development of any hydrocarbon field is very much dependent upon accurate delineation of its structural grain both at smaller and larger scales. Reservoir compartmentalization is very much controlled by smaller faults which sometimes are difficult to see and interpret correctly from both 2D and 3D seismic data. However, such minor faults have been interpreted precisely in one of the Abu Dhabi Oil Fields (Field "A") using borehole imagery and well log data from nineteen wells. The sealing nature of fault planes was determined primarily on the basis of visual examination of the downhole images. The findings were later confirmed by reservoir pressure data.
Minor-scale structural features like fractures can play a vital-role in enhancing the permeability of reservoirs with variable matrix permeability like the Thamama. Therefore, an attempt was made to characterize the fractures in terms of their morphology and origin. Three types of processes were identified as the causes of stresses: fault, overburden and folding related stresses which eventually fractured not only the tight carbonates but also the porous carbonates of the Thamama in field "A".
The results of the study are being employed in conjunction with 3D seismic to refine the structural model of the field. The fault and fracture data have helped to explain the anomalies in pressure and production data of the Thamama reservoirs in field "A".
AAPG Search and Discovery Article #90942©1997 AAPG International Conference and Exhibition, Vienna, Austria