Anadarko Petroleum Corp. and its partners Monday announced a “substantial” discovery at the deepwater Gulf of Mexico (GOM) Heidelberg prospect, which is located in Green Canyon Block 859.

Heidelberg is located in 5,000 feet of water and, to date, has been drilled to a total depth of 28,500 feet. The discovery well encountered more than 200 feet of net oil pay in several Miocene sands.

Anadarko operates the block with a 44.25% stake. Mariner Energy Inc. and ENI each holds a 12.5% interest, and StatoilHydro holds a 12% stake. ExxonMobil Corp. and Cobalt International Energy LP each holds a 9.375% interest in the prospect.

“The Heidelberg discovery further validates our geologic understanding of the subsalt Miocene trend,” said Anadarko’s Bob Daniels, senior vice president of worldwide exploration. “The well encountered the same-age sands and reservoir characteristics similar to the previously announced Caesar/Tonga discoveries.”

The Caesar prospect was discovered in 2006 in Green Canyon Block 683; the No. 1 well drilled to a total depth of 29,721 feet (see Daily GPI, May 18, 2006). The West Tonga prospect also is located in the deepwater of Green Canyon on Block 726 (see Daily GPI, Dec. 5, 2007).

Since 2005 Anadarko has drilled seven successful exploration wells in this Middle Miocene trend, each targeting resources of more than 100 million bbl, Daniels noted. The discovery well’s proximity to Anadarko’s 100%-owned Constitution spar may give the company more flexibility as it considers how to develop the region, the company said. In 2006 the first well in the Constitution field ramped up to a production rate of 15,000 b/d of oil and 12 MMcf/d of gas (see Daily GPI, March 31, 2006). Constitution is located in the Green Canyon on blocks 679 and 680.

More appraisal on the Heidelberg prospect is expected in the second half of 2009, Anadarko said.

Once drilling operations are completed at Heidelberg, Anadarko plans to drill the Vito prospect in the deepwater Mississippi Canyon Block 984, which it operates with a 20% working interest. Vito is a 30,500-foot test, targeting Miocene sands in 4,000 feet of water. According to Anadarko, the Vito prospect is on trend with recent discoveries by BP American Inc. at the Kodiak and Freedom prospects (see Daily GPI, Oct. 15, 2008).

Anadarko also is drilling the Shenandoah prospect, which is located in Walker Ridge Block 52 of the emerging Lower Tertiary trend. Anadarko operates Shenandoah with a 30% stake. In addition, an exploration well is set to spud by the end of March at the Samurai prospect, which is operated by Anadarko with a 33.33% interest. Samurai is located in Green Canyon Block 432.

©Copyright 2009Intelligence Press Inc. All rights reserved. The preceding news reportmay not be republished or redistributed, in whole or in part, in anyform, without prior written consent of Intelligence Press, Inc.