AWT is helping with initial data accumulation stage – amassing subsurface data from a number of companies in the consortium – under the guidance of Canadian-listed independent TAG Oil as consortium operator.
“This engineering work is underway and scheduled to be completed by the first quarter of next year, at which point the consortium will decide on the technologies to trial in a six-to-eight well deep gas program that is scheduled to start in the second quarter of 2007,” TAG president Drew Cadenhead told PetroleumNews.net.
He said TAG had already contracted AWT to help it with the Radnor-1A sidetrack well, in mining licence PMP 38157, which flowed poorly during initial testing last month.
TAG perforated an Eocene-aged McKee sandstone formation interval for testing at Radnor-1A, but initial flows were considered sub-economic.
The interval from 4265-4286m measured depth was perforated, with no water flowing into the well bore from the under-bearing sands of the Kapuni Formation.
“The initial results were a little less than desired,” Cadenhead said.
“We flared some gas to surface so we know we have gas down there, and a trapping mechanism. However, it seems there are problems with permeability inhibiting gas flows, and the resultant poor productivity of the well.”
Radnor-1A is a sidetrack of the Radnor-1 well that two years ago flowed at rates of up to 5 million cubic feet of gas per day before watering out.
Participants in the sidetrack operation are operator TAG (which holds a 33.33% stake) and Bridge Petroleum (33.33%), with TAG assuming another 33.33% interest on a sole-risk basis. TAG is entitled to recover 15 times the cost of the sole-risk venture before any revenue reverts back to the partner that did not participate in the operation, Westech Energy New Zealand.
Cadenhead said the partners should decide on the next step to take at Radnor-1 by the end of the month or early November.
He added that the problems at Radnor were “the perfect fodder” for the Taranaki deep gas consortium.
“We have to determine how to drill and or complete these Eocene-aged wells so they flow at economic rates.”
In May, TAG called for New Zealand deep gas explorers to join forces to coordinate onshore drilling programs and facilitate field development and production, with Cadenhead saying several previously drilled fields – including Radnor, Cardiff and Kahili – were under-performing for various reasons.
The analysis of combined corporate subsurface data should highlight ways to optimise production from tight deep gas reservoirs.
Cadenhead has already said this might involve under-balance drilling, horizontal wells, high-angle laterals, different fracture stimulation techniques, different completion methods, or any combination of these.
AWT is the second downhole specialist called in to help solve onshore Taranaki’s deep gas problems. Cardiff operator Austral Pacific Energy recently commissioned Aberdeen firm Fracture Technology to review testing and fracture stimulation operations on the troublesome Cardif-2A well and to recommend the design and planning of future testing options.
