BP has announced the drilling of a successful appraisal well in a previously untested southern segment of the Mad Dog field.

The 826-5 well is located on Gulf of Mexico Green Canyon block 826, about 100 miles (160km) south of Grand Isle, Louisiana, in about 5,100ft (1,554m) of water.

The well encountered about 280 net feet (85m) of hydrocarbons in the objective Miocene hydrocarbon-bearing sands and discovered an oil column of more than 2,200ft (670m).

The results from the well continue the successful phased development of the Mad Dog field and build upon 2008’s success when the A-7 well in the western part of the field encountered a hydrocarbon column of more than 2,500ft (762m), and 275ft of net pay (84m).

“With these additional hydrocarbon resources in the west and south of the field, Mad Dog has been firmly established as the third giant field in BP’s Gulf of Mexico portfolio, joining Thunder Horse and Atlantis,” said BP’s CEO for exploration and production Andy Inglis.

He went on to say that the company is reviewing development options “to increase production from Mad Dog either through debottlenecking the existing facility or by adding another production facility.”

BP maintains a 60.5% working interest in Mad Dog. BHP Billiton has a 23.9% interest and Chevron Corporation holds a 15.6% interest.