Chevron continues to notch up some substantial Paleogene prizes in the deepwater Gulf of Mexico, with its latest oil find described by partner Cobalt Energy as “very large”.

The Anchor well is the US major’s second such GoM find in three months, following on from its Guadalupe oil discovery in Keathley Canyon Block 10 (see DI, 27 October 2014, page 6). The Anchor well was drilled by Pacific Drilling’s Pacific Santa Ana drillship in Green Canyon Block 807, with the probe hitting oil pay in multiple Lower Tertiary Wilcox Sands.

The well, spudded in August, is located approximately 225 km offshore in a water depth of 1,580 m (5,183 ft), and was drilled to a total depth of 10,287 m (33,749 ft). Appraisal drilling will begin this year, says Chevron.

Jay Johnson, senior vice president, upstream at Chevron, described Anchor and Guadalupe as “significant finds for us in the deepwater GoM. We had one of our best years with the drill bit in 2014, reporting more than 30 discoveries worldwide and adding an estimated 1 Bbbl of new resources to our holdings.”

The operator currently has five deepwater drillships operating in the GoM, two of which are carrying out exploration drilling.

Chevron operates Anchor with a 55% working interest, with its partners being Cobalt International Energy (20%), Samson Offshore (12.5%) and Venari Resources (12.5%).

Partner Cobalt, apart from describing Anchor as very large, added that the well encountered significant high quality pay and was its own fourth significant subsalt discovery in the deepwater GoM. “The Anchor discovery well is clearly one of the best wells we’ve drilled to date in the deepwater GoM. This exceptional discovery is the result of many years of hard work to identify and mature this exciting prospect and to successfully acquire and unitise the Anchor leases,” said James W. Farnsworth, chief exploration officer.

Cobalt, of course, already has stakes in deepwater Gulf discoveries including Heidelberg, Shenandoah, North Platte and now Anchor. Production from Heidelberg is due to start flowing in 2016, and will represent Cobalt’s first production and revenue.

  • Cobalt added that the first appraisal well on the North Platte Inboard Lower Tertiary discovery is expected to spud during this quarter using the newbuild Rowan Reliance drillship in Garden Banks Block 959.

Elsewhere, off Angola in Block 21 the Mupa-1 exploration well encountered non-commercial hydrocarbons and has been plugged and abandoned, said Cobalt. The Petroserv SSV Catarina rig has now moved to Block 20 where it is drilling the Orca-2 appraisal well on the presalt discovery in the Kwanza Basin. Block 21 is operated by Cobalt (40%) in partnership with Sonangol P&P (60%), while Block 20 is operated by Cobalt (40%) again with Sonangol P&P (30%) and also BP Exploration (30%).