Morondava Basin, Offshore Madagascar — New Long Offset Seismic Data Highlights the Petroleum Prospectivity of this Emerging Frontier Basin

Roberts, Glyn; Christoffersen, Trond; Weining, Huang

The Morondava Basin is a large (220,000 sq km) basin situated on the southern half of Madagascar's west coast. It covers both the onshore and the offshore. Onshore, exploration started over a hundred years ago but has been dominated by heavy oil discoveries such as those at Tsimiroro and Bemolonga with some oil and gas shows but no commercial production. Offshore the Basin is more lightly explored, with regional seismic data in the Mozambique Channel and a small number of wells (6) in the shallow offshore. The presence of an active hydrocarbon system is indicated by gas shows in some of the wells; by gas chimneys and brightening on seismic data (Tamannai 2008); and by geochemical sampling of sea-bottom sediments - the latter indicating oil with similarities to samples found in Anadarko's Windjammer well in the Rovuma Basin of Mozambique (Oil Review Africa, Issue 3, 2012).

This paper is based on the analysis of approximately 14,000 line kms of long offset 2-D seismic data (plus gravity and magnetic data) acquired in late 2012/early 2013 in the offshore part of the Morondava Basin by BGP as a multi-client survey under the jurisdiction of the government authority: OMNIS; and in preparation for a new International Bid Round.

The paper looks at the evolution of the Basin and draws comparisons with its conjugate margin off Tanzania and with the discoveries there and in the adjoining Rovuma Basin of Mozambique.

The paper will feature numerous seismic sections from the new survey and will cover the different play types and trap styles in the Basin before drawing conclusions about its prospectivity as regards to both oil as well as gas.

AAPG Search and Discovery Article #90163©2013AAPG 2013 Annual Convention and Exhibition, Pittsburgh, Pennsylvania, May 19-22, 2013