WHELLER, DAVID A., STEPHEN R. CARNEY, RICHARD E. DRUMHELLER and STEPHEN   I.WINSTANLEY Anadarko Algeria Corporation, London, UK, MOHAMED HADJALI Sonatrach,Algiers,Algeria, ALAN J. SCOTT Scott and Associates, and Anadarko Algeria Corporation, London, UK.

Abstract: Sedimentology and Reservoir Characterisation of the Hassi Berkine South (HBNS) Field Block 404, Berkine Basin, Algeria

Several distinct reservoir types including fluvial, aeolian and deltaic sandstones have been delineated in Triassic strata in the Hassi Berkine South (HBNS) field, Berkine Basin,Algeria. Since its discovery in 1995 an excellent database including extensive core, log and petrographic data has been acquired for reservoir description.

The Triassic strata was deposited on a low-relief Paleozoic erosional surface (Hercynian Unconformity).The majority of reservoir sands were deposited in a fluvial braidplain environment that drained to the northeast.Aeolian processes periodically reworked these sands. Laterally extensive lacustrine shales cap the sand-rich intervals. Lake-levels fluctuated significantly due to climatic and base level change and associated deltas contributed sand to these lakes.

Core plug porosity and permeability data were crossplotted by facies and analysed statistically. An analysis of reservoir storage capacity (%phih), flow capacity (%kh) and the generation of modified Lorenz plots by reservoir layer, clearly identify the key layers and provide an indication of the reservoir heterogeneity. An indication of reservoir deliverability is obtained by generating a k/phi curve, which helps identify potential hydraulic conduit zones, local baffles and barriers. Capillary pressure and pore throat profiles data have been analysed by facies and integrated with petrology data, which help to further characterise the reservoir.

AAPG Search and Discovery Article #90923@1999 International Conference and Exhibition, Birmingham, England