Hydrocarbon Geology Characteristics and Oil & Gas Resource Potential in the Afghan-Tajik Basin

Abstract

The Afghan-Tajik Basin is an intermontane depression between the mountain ranges of Gissar and Pamirs, and Jurassic system and Tertiary system are rich in large oil & gas resources. In order to assure sustainable supply of oil & gas from Central Asia, we deeply researched hydrocarbon geology characteristics and resource potentials. The basin belongs to paralic sedimentary environment, and develops 3 sedimentary strata: Jurassic, Cretaceous, and Tertiary. Afghan-Tajik Basin develops 3 main source rocks including clastic rocks of Jurassic, carbonate rocks of Cretaceous and mudstone rocks of Eocene. The basin develops 2 plays: Jurassic-Cretaceous play is gas containing one, and Tertiary play is oil containing one. Plaster stone and salt rock of upper Jurassic are regional cap rocks of Jurassic-Cretaceous gas pool, and creaming mudstone and muddy limestone of Cretaceous and Tertiary are regional or partial cap rocks. Migration and accumulation of hydrocarbon occur in the late Cretaceous and early Pliocene epoch. Afghan-Tajik Basin has larger exploration potentials, and residual resources are 2.4¡Á108t. The potential zones are as follows, south part of basin, oil-gas structures of post-salt, reef limestone of pre-salt, and litho-stratigraphic traps.