PROSPECTIVITY OF THE DEEPWATER GULF OF PAPUA AND SURROUNDS IN PAPUA NEW GUINEA (PNG)—A NEW LOOK AT A FRONTIER REGION

Abstract

Despite limited well control and paucity of seismic data, a regional study of the deepwater portion of the Gulf of Papua, Papua New Guinea (PNG), indicates a number of large structures at a variety of stratigraphic levels that are capable of holding significant volumes of hydrocarbons. The main structural elements east of the Fly River Platform the Pandora Ridge, Pandora Trough, Aure Trough, Port Moresby Trough and the northern portion of the Eastern Plateau were established during the Paleozoic and further enhanced by Late Cretaceous to Early Paleocene Coral Sea rifting in the southeast. Structuring in the region is mostly basement involved and extensional, and is overprinted by a later compressional pulse. Extensional and compressional regimes produce many potential traps. To date, exploration in the Gulf of Papua has been sporadic and mainly focussed in shallow water depths. The new reprocessed seismic data indicate the following Paleozoic to Recent plays, some of which contain multiple reservoir-seal pairs, sourced by non-marine and marine source rocks:

extensional Paleozoic rift fault blocks;

Upper Jurassic to Lower Cretaceous turbidites (Iagifu- Hedina-Toro sandstone equivalents);

Campanian to Middle Paleocene Coral Sea synrift sandstone and basin floor fan equivalents (Pale/Barune Formations and equivalents);

Middle Paleocene break-up unconformity fault blocks and intra-basinal highs;

Upper Paleocene to Lower Eocene Pima Sandstone equivalent associated with the Middle Paleocene uplift and erosion;

Oligocene to Lower Miocene lowstand deltas and turbidites;

Miocene to Recent biohermal build-ups (possibly including a new limestone high, the Box Ridge, in front of the Pandora Ridge); Karstified Darai Limestone equivalent sealed by Aure Beds claystones;

Miocene to Recent lowstand deltas and turbidites;

Eocene to Pliocene stratigraphic onlaps flanking main structural highs; and,

compressional plays associated with the Pliocene to Recent collision of the PNG and Pacific plates.