Cooper basin find indicates two prior strikes linked
Innamincka Petroleum Ltd., Brisbane, has made an oil discovery with its Flax East-1 well in the Cooper basin of South Australia.
MELBOURNE, Oct. 2 -- Innamincka Petroleum Ltd., Brisbane, has made an oil discovery with its Flax East-1 well in the Cooper basin of South Australia. The company says the find confirms that two previous discoveries at Flax and Juniper fields are connected and could boost total oil in place to 120 million bbl.
Innamincka explains that the successful Flax East-1 was drilled in the structural saddle between the two highs. Wireline log data from the well indicate that the Permian Patchawarra formation and Tirrawarra sandstone targets are oil-saturated with no evidence of water saturation in the reservoirs.
Innamincka says the find has lowered the known base oil level by about 24 m, and there is a reasonable basis for concluding that Flax-Juniper field will prove to be one of the largest onshore oil fields in Australia.
The company has drilled eight wells in the field area, located in Permit PEL 103 about 50 km northeast of Moomba on the South Australia-Queensland border. All of them have encountered oil-saturated sands in the primary target interval with an average net pay thickness for the basal Patchawarra-Tirrawarra of about 7 m.
The Flax East-1 has a net pay of 10.2 m in the primary zone, and the sands in question were better developed than in most of the other wells in the region. The well has been cased and suspended for future production.
Meanwhile, Flax field itself is under development with well completion and fracture stimulation beginning in early August this year. All four wells at Flax have required fracture stimulation, and the postfrac clean-up flows have varied considerably.
Flax-1 is expected to have a flow rate capability of 300-350 b/d of oil. It flowed 600 b/d on test when found in January 2004.
Flax-2 has an initial postfrac flowback of 200 b/d of fluids (150 b/d of oil and 50 b/d of frac fluid).
Flax-3 has a postfrac clean-up flow of 700 b/d of fluid (580 b/d of oil and 120 b/d of frac fluid), while Flax-4 is flowing postfrac at 200 b/d of fluids (160 b/d of oil and 40 b/d of frac fluids).
Production is also constrained by the limited field infrastructure. Innamincka says temporary flowlines to be installed this month should lead to consistent production.
A gas compressor expected at the field late in October will be used to reinject produced gas into the reservoir via Flax-1. The company hopes to have a production of 1,000 b/d of oil from the initial wells by the middle of next year.
The crude is 52º gravity. Solution gas in the reservoir has been measured at 2.5 Mcf/bbl of oil.
Innamincka expects that the two wells drilled on the Juniper structure plus the just-completed Flax East-1 will also prove to be commercially viable.
The total reserves estimate following the Flax East-1 result will be assessed in an independent report likely to be completed by January 2008.
The need of the Permian reservoirs for fraccing will limit the recovery factor, which according to some initial estimates might be as low as 15%.
A recent decision by Santos to build an oil pipeline from Jackson field in Queensland to Moomba in South Australia will provide Innamincka with the option of laying a connecting line from the Flax-Juniper fields.
Innamincka holds 75% interest in PEL 103 block. Seoul City Gas, South Korea, holds the remaining 25%.