The partners must be disappointed at the field’s rapid decline, with production falling despite more wells being brought online.
Production began at the end of March 2005 from four horizontal development wells. Soon after start-up in late March 2005, production was ramped up to an initial rate of 105,000 barrels of oil per day. The fields then produced on free flow at around the facility design capacity of 100,000 barrels per day before being stabilised by May at a rate of about 90,000bpd.
But by the end of the first quarter of this year, junior partner Woodside was already talking about ‘natural decline’ at Mutineer-Exeter.
According to the latest Santos quarterly, net production from Mutineer-Exeter decreased by 22% in the second quarter to 900,000 barrels compared with the first quarter, which averaged a gross production rate of about 29,000bpd.
However, the Mutineer-12 development well was successfully drilled and brought online on June 20, significantly increasing production late in the quarter. Two further development wells (Exeter-7 and 8) are currently being drilled.
By the end of the quarter, Mutineer-Exeter production was averaging about 55,000bpd gross, still just more than half of initial production rates.
Santos’ overall quarterly oil production of 3.06 million barrels (MMbbl) was 5% lower than in the 2006 first quarter.
“This was predominantly due to downtime at Mutineer-Exeter associated with drilling and completing the Mutineer-12 development well, together with natural field decline,” the company said.
Offshore Western Australia development drilling on the Mutineer-Exeter oil field increased daily production rates from 35,000bbl to 55,000bbl by the end of the quarter.
Two more development wells are being drilled on the field and are expected to be brought into production this half.
Interests in the Mutineer-Exeter project (WA-26-L and WA-27-L) are Santos, which holds a 33.4% stake, KUFPEC (33.4%), NipponOil (25%) and Woodside Petroleum (8.2%).
Elsewhere in the offshore Carnarvon Basin, Santos is planning to drill a follow-up well to last year’s Hurricane discovery, according to junior partner Mosaic Oil.
The Hurricane-1 wildcat intersected a 76m gross gas column in WA’s offshore Eastern Dampier Sub-Basin in January last year.
The joint venture was actually chasing oil. The prospect has been estimated to have mean potential recoverable oil reserves of 24MMbbl and an estimated potential of 75MMbbl of oil in-place, according to Mosaic.
“Santos as operator of the WA-208-P joint venture is actively looking to secure a rig slot to drill Huricane-2 to appraise the possibility of an oil leg down-dip of the Hurricane location,” Mosaic said yesterday.
“We anticipate the Hurricane-2 well will be drilled before the end of the March 2007 quarter.”
Interests in WA-208-P are Woodside (34.03%), operator Santos (31.31%), ENI Australia (18.66%), Beach Petroleum (10%) and Mosaic Oil (6%).
