Tower Resources PLC completed a basin modeling of license PEL 96 in Namibia, covering offshore blocks 1910A, 1911, and 1912B, to identify prospects and leads in the license. The basin and thermal maturity study progressed understanding of the hydrocarbon prospectivity of the license.
The objectives of the basin modelling study were to assess critical elements of the hydrocarbon charging system, i.e. thermal maturity, distribution of generative source kitchens, volumetric estimation of generative capacity of mature source rocks, timing of generation and expulsion of hydrocarbons, and mapping of migration pathways.
The study has been integrated with seismic sequence stratigraphic interpretation of the large 2D seismic datasets and with PEL96 and other Walvis basin region well data. The data show clear evidence of a working petroleum system present within the Dolphin Graben in PEL 96 based on oil recovered from 1911/15-1 well cores and direct hydrocarbon indicators observed on seismic.
The study calculated and mapped generative source kitchens within PEL 96. Lower Cretaceous syn-rift sediments within the main depocenters of the Dolphin Graben calculate as mature for main oil and late oil generation. Timing of the main and late oil generation phases calculate as mid-Tertiary (Oligocene) to present-day.
Main fetch areas that focus migration towards each of the prospects have about 45-79 billion bbl potentially generated oil in Alpha Prospect and 15-23 billion bbl in Gamma Prospect.
Potential for stratigraphic traps is recognized on the 2D seismic data where Cretaceous reservoir targets onlap onto highs along the western and eastern flanks of the Dolphin Graben. These potential stratigraphic traps are directly on several of the main migration pathways out of the generative kitchens and show similarities to recent major discoveries in South Africa and Namibia.
Tower is currently undertaking an oil seep analysis to accompany the basin modeling work and a review of the existing volumetric data on the prospects and leads that have already been identified.
Jeremy Asher, Tower's chairman and chief executive officer, said the results of the basin modeling work indicate the prospectivity of Tower's licenses in Namibia. “It explains neatly the results of the Norsk Hydro well, the source of the lacustrine oil found within it, and the reasons why that oil found its way into that well and subsequently migrated away from it,” he said.
“The conclusions indicate the potential for either of the giant billion-barrel-plus structures in the West of the license to be charged; furthermore, the migration pathways, coupled with the recent impressive industry successes in drilling stratigraphic plays in Orange basin to the South, enhance our interest in the similar stratigraphic leads that we interpret on the flanks of the Alpha Prospect structure in particular,” he said.
Tower is the operator of license PEL 96 with 80% working interest.
Alex Procyk | Upstream Editor
Alex Procyk is Upstream Editor at Oil & Gas Journal. He has also served as a principal technical professional at Halliburton and as a completion engineer at ConocoPhillips. He holds a BS in chemistry (1987) from Kent State University and a PhD in chemistry (1992) from Carnegie Mellon University. He is a member of the Society of Petroleum Engineers (SPE).
