Crown Minerals Seismic Survey a Resounding Success

Crown Minerals has successfully completed an offshore seismic survey, off the southeast coast of the South Island, as part of a blocks offer planned for the Great South basin later this year.

The government sponsored seismic survey, DUN06, was successfully completed with 3,160 km of 2D seismic data being acquired.

“At the end of the day the survey was a tremendous success” said Crown Minerals geophysicist Ricardo Bertolotti, who was responsible for this survey; “we have accomplished all our goals and more”.

The survey was the second to be completed under the $15 million budget approved by Cabinet in September 2004.

Multiwave geophysical were contracted to acquire the data using their 65 m vessel the Pacific Titan. A 6 km long solid state streamer was used.

DUN06 includes a grid off the coast of the South Island between Dunedin and the Catlins, as well as lines that extend into the heart of the Great South basin.

The survey area was chosen to test the prospectivity of the area between the Great South and Canterbury basins. “Looking at the raw data suggests that the basin extends to the northeast providing potential for hydrocarbon prospectivity” said Bertolotti.

Data was acquired in the heart of the Great South basin to provide modern data to accompany the Hunt survey data acquired in the early 1970’s. Bertolotti says “This new data will complement the Hunt data by providing better imaging of the geology through to basement than was previously available; we also tied the seismic to several wells”

Five wells were tied, including Tara-1 and Toroa-1, that both had strong oil and gas shows, and Kawau-1A that was a gas discovery.

The survey took six weeks to acquire, and although not completely without interruption, included a two week period without weather related down time.

The seismic survey was acquired in the area that will shortly be opened for the Great South basin exploration permit blocks offer.

This data will be made freely available to interested parties in order to help facilitate a successful blocks offer bids over the highly prospective Great South basin.

GNS Science was awarded the contract to process the survey. This will be completed by August 2006.

Concurrent to this substantial 2D seismic acquisition, GNS Science have been awarded a contract to re-process approximately 8,000 line km of existing 2D seismic data. This will also be distributed freely to interested parties. Crown Minerals has also commissioned and completed an enhanced well data project, which was finished in early February 2006.