ABSTRACT: Indus Basin, Pakistan: Hydrocarbon Plays

KEMAL, ARIF, Oil and Gas Development Corporation, Islamabad, Pakistan, HUGH BALKWILL, Petro-Canada Resources, Calgary, Alberta, Canada, and FRANK STOAKES* and CLARENCE CAMPBELL, Stoakes-Campbell Geoconsulting Ltd., Calgary, Alberta, Canada

Polyphase tectonism along the northwestern margin of the Indo-Pakistan craton produced the Indus basin, having a stratigraphic and structural record spanning late Proterozoic through Cenozoic.

Late Proterozoic rifting of the northern periphery of the Gondwanaland supercontinent evolved to an Infracambrian and Paleozoic stable platform. Permian and Mesozoic rifting preceded and accompanied Gondwanaland break-up. Early Tertiary, wrench-induced, intrabasin differential subsidence and uplift took place during collision with microplates along the northwestern margin. Middle and late Cenozoic plate collision along the northern and western margins of the craton led to development of a complex orogen and a contiguous foredeep basin with thick terrigenous clastics.

A northeastward-thickening succession of Infracambrian and Paleozoic strata yields hydrocarbons in the northern Indus basin. These carbonate, evaporite, and terrigenous clastic rocks have fracture and intergranular porosity. A westward-thickening Mesozoic and lower Cenozoic wedge is dominated by carbonates, interpreted as products of long-lasting marine highstands; intervening terrigenous clastics mark widespread marine lowstands. Widely distributed, producing and prospective reservoirs within these strata include fractured and karsted carbonate intervals, build-ups, and deltaic and marginal marine sandstones. Oligocene and younger terrigenous clastics of the orogenically derived foreland wedge are less prospective than older successions because they lack predictable internal seals.

Indus basin structural plays are divisible into two main categories: Basement-involved structures include Cretaceous horsts, early Tertiary wrench structures, and elements attributable to late Cenozoic regional convergence; structures detached above basement include the products of multiple stages of evaporite solution and collapse, intrastratal extensional gliding, and multiple-level decollement during late Cenozoic convergence.

Indus basin stratigraphic plays include subcrop traps at several Paleozoic, Mesozoic, and Cenozoic levels, and some Lower Tertiary carbonate build-ups.

AAPG Search and Discovery Article #91012©1992 AAPG Annual Meeting, Calgary, Alberta, Canada, June 22-25, 1992 (2009)