LONDON – Statoil (UK) remains committed to developing the Mariner heavy oil field in the UK North Sea, according to partner Nautical Petroleum. Since becoming operator, Statoil has acquired high-resolution 3D seismic and ocean bottom cable seismic over the field, in addition to a platform site survey performed this summer.
The combination of the 3D and OBC seismic – a technique proven on Statoil’s Grane heavy oil field in the Norwegian sector – has improved imaging and definition of the areal distribution of Mariner’s Heimdal Sandstone reservoir, and characterization of the Maureen Sand reservoir, ”increasing” the hydrocarbon column. In addition, areas of Maureen Sand erosion proved to be more limited than previously mapped.
Nautical says other studies show a likely reduction in platform drilling costs, increased recovery rates, and decreased water cut through use of autonomous valves. These results will be incorporated into a revised reservoir simulation, with no further drilling required.
Best estimate contingent resources for Mariner presently are 369 MMbl. Nautical expects a field development plan to be submitted in 2011, leading to first oil in 2015.
Near Mariner, Nautical operates a smaller heavy oil discovery, Kraken. The company’s test well on Kraken’s northeast flank (9/2b-3) was designed to intersect the oil/water contact and to investigate potential upside. However, the targeted Heimdal Sandstone reservoir was absent. Nautical remains upbeat, claiming there are further potential resources and exploration upside to the north, south and west of Kraken, with potentially 114 MMbbl in place. It plans to integrate sedimentological and seismic studies with results from a controlled source electromagnetic survey conducted this June to site an appraisal well for next year. It aims to issue a development plan before the end of 2010.