Abstract: Recent Advances in Prospect Mapping and Appraisal Drilling in the Hides Gas Field, Papua New Guinea Fold Belt

Andrew Grainge

Significant quantities of hydrocarbons are now being successfully produced from the Papuan Fold Belt. Of the 26 structures drilled to date in the fold belt Toro fairway, over half have been discoveries, and all have been made in readily identified thrust related anticlines, mapped using a combination of surface dip data and conventional displays of topography, aerial photographs and airborne radar. Widespread outcrop of karstified Tertiary limestone renders seismic data almost useless in prospect mapping in the fold belt.

This paper briefly reviews some of the recent developments in prospect and field mapping techniques which led the discovery of a potentially giant gas field, where a 1000 m vertical column of gas has been proven by the Hides 3 appraisal well. Recent work conducted in the Hides area, integrates these developments in interpreting both the surface (airborne radar and strontium age dating of the Darai) and sub-surface (magnetotelluric modelling, Toro fluid inclusions and regional aquifer pressures) with conventional methods, based on geological survey and well data.

This work has provided a much better resolution of the surface geological map, which in turn has had a direct impact on the subsurface structural model used to estimate potential reserves. However, the range of model uncertainty remains considerable primarily due to a lack of an identified hydrocarbon water contact in the Hides/Karius structure and a very limited areal spread of well control.

AAPG Search and Discovery Article #90986©1994 AAPG Annual Convention, Denver, Colorado, June 12-15, 1994