SEARCHER Seismic has announced the completion of the regional multi-client airborne gravity, gravity-gradiometry and magnetics survey covering the transition zone of the Gulf of Papua.

The Roho Airborne Gravity, Gravity-Gradiometry and Magnetic Survey covers approximately 60,700 square kilometres (~52,700line km) along the southern coast of PNG. The survey compliments several marine seismic and geochemical projects recently completed by Searcher aimed at assessing the hydrocarbon potential of the Gulf of Papua and adjacent Coral Sea areas, offshore PNG. The data were acquired with a one km line spacing in the northern Gulf of Papua, and 2km line spacing extending along the coastline to SE PNG.

Much of the area covered by the Roho Survey were comprised of shallow water transition zone environments where seismic operations are difficult and expensive. The survey was acquired by CGG Multi-Physics, using a Basler BT-67 and a DHC-6 Twin Otter twin turbine fixed wing aircraft.

Andrew Weller, Geoscientist and Asia-Pacific sales manager for Searcher Seismic, said the survey was designed to bridge the gap between the onshore areas of PNG where many wells have been drilled, providing good geological control points, with the offshore regions in the Gulf of Papua and Coral Sea, where a substantial database of new, high quality seismic data is now available, and well data is sparse or absent all together.

“The Roho Survey provides the exploration industry with the largest and most coherent dataset over a significant portion of the Gulf of Papua’s transition zone environment. The Roho Survey complements Searcher’s existing 2D seismic coverage which currently stands at over 87,000 kilometres, 3,888 square kilometres of 3D as well as a geochemical survey, offshore Papua New Guinea,” Mr Weller said.

“Final data is now available for the Roho Survey. A regional interpretation of the new data will be available by March 2019. Initial interpretation reveals a complex history of extension and compression along the southern margin of the East Papuan Peninsula.

“On the Fly River Plateau at the northern end of the Gulf of Papua, a more comprehensive picture has emerged of the Pre-Cenozoic structural geometry, delineating a Mesosoic rift complex blanketed by a Cenozoic foreland cover.  Along the southern East Papuan Peninsula, recent extensional events have been identified associated with the development of the offshore basins to the north.  By contrast the western margin of the East Papuan Peninsula is characterised by discrete foreland basin development,” Mr Weller added.