Abstract: Delineating Multiple Sediment Provenances and Their Effects on Reservoir Quality; Offshore South Caspian Basin

RUEHLMAN, JOHN, DR. ROBERT KLIMENTIDIS, and DR. SAFURA SULEYMANOVA

While over 25 million barrels of oil have been discovered in the onshore and shallow-water offshore sectors of Azerbaijan and Turkmenistan, the deep-water Caspian Sea remains relatively undrilled. This area is characterized by up to 6000 m of the prospective section, having been deposited in less than 3 m.y. by river systems sourced by multiple provenances, resulting in a very complex succession of clastic rocks. Defining the geographic and stratigraphic distribution of the rocks representing the different provenances and their respective reservoir quality with depth will be a key to exploration success.

Sandstones representing three provenances have been identified by their compositional signatures, and each has different reservoir quality at depth. Integration of thin-section petrography, scanning electron microscopy, porosity and permeability measurements and mercury injection capillary pressure analysis allows us to characterize pores, estimate producible porosity and model porosity vs. depth for different areas of the basin. Results include prediction of greater than 20% porosities at depths exceeding 6000 m in quartz-poor, lithic-rich sandstones.

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