Ophir-BG has Rovuma gas find off Tanzania

April 4, 2011
Ophir Energy PLC and BG Group made a third gas discovery in a deepwater exploratory drilling program program off Tanzania.

By OGJ editors
HOUSTON, Apr. 4
– Ophir Energy PLC and BG Group made a third gas discovery in a deepwater exploratory drilling program program off Tanzania.

Ophir Energy hasn’t disclosed the size of the three discoveries. However, the company said, “There are now early indications that there could be sufficient volumes of gas present within the acreage held by Ophir to support the construction of one or more liquefied natural gas processing facilities, which will allow for the export of gas to world markets.”

The Chaza-1 well, in Block 1 in the northern part of the Rovuma basin, went to a total depth of 4,895 m subsea in 952 m of water 18 km off Mnazi Bay. Ophir Energy said only that the well encountered a high quality gas bearing reservoir associated with a distinctive seismic anomaly.

The Rovuma basin is the location of four deepwater gas discoveries by an Anadarko Petroleum Corp. group off Mozambique. An estimated 40 miles separates Chaza-1 from Windjammer, the Anadarko group’s northernmost discovery to date in Offshore Area 1 (see map, OGJ, May 17, 2010, p. 35).

Chaza, the first discovery in Block 1, is 200 km south of Ophir Energy-BG Group’s Chewa-1 and Pweza-1 gas discoveries on Block 4 in the Mafia basin.

Ophir Energy is operator of blocks 1, 3, and 4 with 40% interest, and BG Group has 60%. BG Group has the option to assume operatorship of all three blocks on completion of the initial work program.

Chaza-1 is the third of a three-well sequence that forms part of an initial work program across the three blocks, which cover more than a combined 27,000 sq km in 100 m to more than 3,000 m of water.

The Deepsea Stavanger semisubmersible will move back to Block 4 to sidetrack and appraise Chewa-1 off Dar es Salaam and deepen it to test older objectives.

The two companies plan to start a second drilling campaign in late 2011. So far this year they have shot 3,200 sq km of 3D seismic in blocks 3 and 4 and are completing 1,800 sq km in Block 1.