Providence sees Porcupine basin oil, gas-condensate potential

July 26, 2010
Providence Resources PLC, Dublin, plans to progress to drilling several prospects in the Porcupine basin off southwestern Ireland after a mid-2009 3D seismic survey indicated three areas of hydrocarbon potential.

Providence Resources PLC, Dublin, plans to progress to drilling several prospects in the Porcupine basin off southwestern Ireland after a mid-2009 3D seismic survey indicated three areas of hydrocarbon potential.

The prospects are on the Atlantic margin on frontier exploration license 2/04, 200 km southwest of Shell-operated Corrib gas field and the same distance off Ireland's west coast and include oil and gas-condensate reservoirs. The block is in 300-400 m of water.

The former Phillips Petroleum Co. made discoveries on the block in the 1970s-80s that were never developed due to remoteness and lack of a gas market (OGJ Online, July 12, 2010).

Providence operates the block with 56% interest on behalf of itself and Chrysaor E&P Ireland Ltd. 30% and Sosina Exploration Ltd. 14%. Interpretation and processing of the 2009 3D seismic survey is under way.

Spanish Point structure

Providence said final processed 3D data show "excellent resolution" of the Upper Jurassic reservoir intervals and allow for the direct mapping of some of the zones across the Spanish Point structure, where a Phillips-led group that included a Providence predecessor gauged a gas-condensate discovery in 1981.

Providence said, "The data confirm the earlier seismic interpretation based on previous 2D surveys that Spanish Point comprises a large structural closure and suggest that further hydrocarbon bearing reservoir zones may be present above those tested by the 35/8-2 discovery well."

That discovery well flowed 5 MMscfd of gas and 1,000 b/d of condensate from one of four Upper Jurassic reservoir intervals in a 1,400-ft thick gross hydrocarbon-bearing section. The license was relinquished.

Seismic interpretation and mapping also indicate an undrilled section as thick as 750 ft above the 1,400-ft hydrocarbon-bearing section that may host more hydrocarbon-bearing zones, Providence said.

Burren oil discovery

The 3D survey also covered the 35/8-1 Burren oil discovery, just southeast of Spanish Point, which flowed 730 b/d of 34° gravity oil in 1978 from one of two logged hydrocarbon-bearing Lower Cretaceous sandstones.

The 35/8-1 well never penetrated its original Jurassic target due to increased downhole pressures, and drilling was terminated at the top of the Jurassic.

The seismic also identified a number of laterally extensive seismic anomalies of similar age that suggest that the Burren discovery could form part of a much larger stacked Lower Cretaceous oil-bearing reservoir system with important future appraisal and exploration potential, Providence said.

Wilde prospect

Meanwhile, previous 2D seismic interpretation indicated the presence of a potentially large structural closure known as the Wilde exploration prospect that underlies the Spanish Point discovery.

Interpretation and mapping of the new 3D data has confirmed the presence of the Wilde prospect with an associated 45 sq km of areal closure.

The Upper Jurassic interval of the Wilde exploration target is of high interest as it is considered to be of equivalent age to Callovian-Oxfordian zones that flowed at a cumulative rate of 5,000 b/d in the nearby 26/28-1 well 30 km north, Providence said.

This well also encountered good reservoir development in the Bajocian-Bathonian section, suggesting further hydrocarbon potential in the underlying Middle Jurassic section.

Providence will arrive at final resource estimates for the Spanish Point discovery in the next 2 months. The estimates will allow the partners to plan appraisal drilling. The company will also generate resource estimates for the Burren oil discovery and underlying Wilde exploration prospect.

Farther south in the Porcupine basin, ExxonMobil Corp. launched a site survey on the Dunquin prospect on behalf of a group that plans to drill an exploration well on the five-block 3/04 license.

The group notified Irish authorities in August 2009 that they elected to enter the second license phase that carries a firm well commitment.

Dunquin interests are ExxonMobil and Eni SpA 40% each, Providence 16%, and Sosina 4%.

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