The jack-up Ensco Rig 107 late last week drilled through the top of the Paleocene-aged Farewell Formation reservoir with the Kupe South-6 well.

This morning Wellington-headquartered NZOG said the three coring operations in the 8½-inch section of the well had been completed and that drilling had now reached a depth of 3313m MDRT (measured depth from rotary table).

The planned total depth for the section was 3385m MDRT - another 72m into the hydrocarbon column encountered. Once TD has been reached, wire-line logs should be run before setting and cementing the five-inch liner, NZOG said.

The other wells are just above the Farewell formation. Kupe South-7 was drilled to a depth of 3116m, and Kupe South-8 to 3429m. Operator Origin Energy is conducting the Kupe development drilling campaign on a "batch-drilling" basis, drilling each section of the three wells sequentially.

Once the rig has finished drilling the wells in the central field area (CFA) of the Kupe mining licence (PMP 38146), it will drill the Momoho-1 well, and then a sidetrack, to test the west and east compartments of the Momoho prospect, which are separated by a fault. Momoho has the potential to contain 100-150 petajoules of gas, although it could also hold oil.

Recoverable 2P (proven and probable) reserves for the Kupe CFA are estimated at 254 petajoules of gas, 14.7 million barrels of condensate, and 1.1 million tonnes of LPG. First gas is expected by mid-2009, at an initial rate of 20 petajoules per annum. The project is estimated to have a 19 year-plus economic life.

The Kupe partners are operator Origin Energy (50%), Genesis Energy (31%), New Zealand Oil & Gas (15%), and Mitsui E&P NZ (4%).