BHP Billiton has made a discovery at the Neptune-5 appraisal well in the Gulf of Mexico. The company drilled in Atwater Valley Block 574, 135 mi from the Louisiana coast. The well encountered a gross hydrocarbon column of 1,200 ft, with more than 500 ft of net oil pay.
The net column is larger than those recorded in the similar Miocene reservoir sandstone intervals of previous Neptune wells, and the preliminary evaluation of the fluids indicates the presence of oil similar i to the medium sour crude found at the Atlantis and Mad Dog fields. BHP drilled the well to 19,142 ft total depth in 6,215 ft of water.
"The well logs at Neptune-5 indicate thick sands and are amongst the most impressive we've seen in the Gulf of Mexico," said Philip Aiken, president and CEO for BHP Billiton Petroleum.
Aiken explained that following the positive result from Neptune-3 in July 2002, the joint venture partners have accelerated the appraisal program at the field over the last year, drilling three wells since mid 2002.
Core and fluid samples have been taken and the partnership is sidetracking Neptune-5 while assessing options for other associated operations at the well.
Neptune-5 spudded on July 2, using the BHP Billiton-operated drillshipCR Luigs. The Neptune prospect is in the Atwater Foldbelt region of the Central Gulf of Mexico. This area includes the Mad Dog and Atlantis fields, which are in development, and the BHP Billiton-operated Shenzi discovery, where an appraisal well will be drilled later this year.
BHP Billiton is the operator on the block with a 35% working interest. Partners are Marathon Oil Co. 30%; Woodside Petroleum 20%; and Repsol YPF subsidiary Maxus Exploration Co. 15%.