Abstract: Scale Variations in Reservoir Properties as a Clue to Reservoir Characterization of the Heterogeneous Pinda (Albian) Formation, Nemba Field, Offshore Cabinda, Angola

COOL, THOMAS E.; BRACKEN, BRYAN; POPEK, JOHN; GONCALVES, FERNANDO; MCLERIE, MIKE; RUSH, PATRICK

Resolution of the heterogeneity of the Pinda (Albian) Formation in fields of the Outer Pinda Trend in Areas B&C, Offshore Cabinda, Angola, has been addressed by extensive coring of development wells in these fields. Reservoir characterization of the Pinda Formation at Nemba Field has been facilitated by recognizing petrophysical characteristics at millimeter and plug scale, using these data to define depositional packages and, ultimately, relating these to seismic scale to define sand-prone fairways.

The pore system and petrophysical characteristics are directly related to depositional facies and lithologies. This system is classified using capillary pressure, petrographic, X-ray diffraction, and petrophysical data. Inherent within this methodology is the routine measurement of petrophysical parameters using capillary pressure data generated by ultra-high pressure mercury porosimetry. These are used as a check on the validity of wire-line log Sw data.

The depositional succession identified in cored wells consists of cycles of seaward and landward stepping shallow marine shelf and shoreface facies. Flow units comprise shoreface portions of the sequences.

Seismic amplitude studies indicate that the 3-D seismic data are not sensitive to fluid content within the reservoir, but are possibly related to reservoir quality (i.e., porosity, net to gross). Development well locations are routinely picked with the aid of seismic amplitudes; recent well results confirm that the method is successful, in both a qualitative and quantitative sense.

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