ABSTRACT: Tectonics Control on the Major Play Types in the Papuan Basin, PNG

PIGRAM, C. J., and P. A. SYMONDS, Bureau of Mineral Resources, Australia, Canberra, Australia

Hydrocarbon discoveries in the Papuan basin occur in three play types: (1) Jurassic-Cretaceous sands with Cretaceous seals in Late Cainozoic thrust related anticlines; (2) Jurassic-Cretaceous sands with Cretaceous seals in wrench related structures; (3) Miocene-Pliocene patch reefs sealed in Late Cainozoic muds. These traps have developed in response to the three major tectonic events that have shaped the gross structural and sedimentary architectural of the New Guinea Orogen.

(a) Early Mesozoic rifting and passive margin formation. A siliciclastic sag phase sequence was draped across this margin during the Jurassic and Cretaceous depositing reservoir and seal facies. (b) Late Mesozoic rifting and wrench faulting. (c) Mountain building from mid Oligocene. The collision initiated several events that influence hydrocarbon accumulation in the Papuan basin including: the reactivation of Cretaceous wrench faults to produce structuring on the Fly platform; the development of the fold and thrust belt which migrated southward and eventually formed the Late Cainozoic anticlinal traps that now contain the major hydrocarbon accumulations in the Papuan fold belt; the conversion of the passive margin to a foreland basin in which the Miocene-Pliocene patch reefs develope on basement blocks formed during the Cretaceous wrenching.

AAPG Search and Discovery Article #91015©1992 AAPG International Conference, Sydney, N.S.W., Australia, August 2-5, 1992 (2009)