Mad Dog appraisal well extends field

March 22, 2005
An appraisal well and three sidetracks drilled on the deepwater Mad Dog Southwest Ridge in the Gulf of Mexico encountered significant hydrocarbon pay.

By OGJ editors

HOUSTON, Mar. 22 -- An appraisal well and three sidetracks drilled on the deepwater Mad Dog Southwest Ridge in the Gulf of Mexico encountered significant hydrocarbon pay.

The original well was drilled to 22,890 ft measured TD on Green Canyon Block 826 to downdip targets in adjacent Green Canyon 825. The blocks are in 5,000 ft of water.

The well and sidetracks tested the field's previously undrilled southwest flank. Each intersected up to 300 ft of net oil pay in the early Miocene section and found hydrocarbons some 700 ft deeper on the west flank of the structure than previously encountered.

The hydrocarbons could be produced through spar development wells or future subsea tie-backs.

Mad Dog field, on the Atwater fold belt, began production in January 2005 from Green Canyon 782. Gross field production is currently about 30,000 bo/d from two wells. Capacity of the truss spar is 100,000 b/d of oil and 60 MMcfd of gas (OGJ Online, Jan. 19, 2005).

BP PLC is the operator with a 60.5% working interest. BHP Billiton Ltd. owns 23.9% and Unocal 15.6%.

The Mad Dog appraisal was drilled from the Discoverer Spirit drillship, which is under contract to Unocal until September. The ship has moved to drill the Knotty Head prospect on Green Canyon 512 and is scheduled to drill the St. Malo-3 appraisal well on Walker Ridge 677.