RECORDS were broken in an extended reach drilling (ERD) campaign employed by Origin Energy on its Halladale and Speculant project fields, in the Otway basin.

Origin drilled the Halladale 2 well to a depth of 6,015 metres to access the offshore reservoir located about five kilometres from the well site.

According to Origin, the well set an Eastern Australian record for the longest ERD section to a total depth in a single drilling run.
Speaking with Oil & Gas Australia, Origin general manager of conventional project delivery and technology, Mike Gray, said after much planning and preparation the company decided to use ERD for the Otway basin project because it minimises environmental and community impact.

“Using extended reach drilling means that there’s no direct interference with the adjacent Bay of Islands Coastal Park,” he said.

With many Victorian offshore projects’ budgets blowing out, companies like Origin are looking at alternative ways to drill, Credit Suisse associate in equity research Martin Kronborg explained when speaking with Oil & Gas Australia.

“What you will see at the moment is companies trying new ways of doing things, because if you can’t develop gas at an all in cost of six or seven dollars then you don’t have a market,” Mr Kronborg said.

Although ERD was Origin’s preferred method for this project, it was not without its challenges, Mr Gray said, adding that the ability of local drilling rigs to execute the job scope was the main challenge.

Modifications such as an overhaul to the top drive system and additional generators added to the rig package were made to the contracted rig to ensure the desired wells could be drilled.

Mr Gray explained the deeper geology in the area was a challenge as significant portions of the high angled hole sections are composed of unstable shales.

“These needed to be controlled by maintaining tight tolerances on drilling fluid properties and adopting strict drilling and tripping procedures,” he added.

A pipeline to transport the gas for processing will still need to be developed as part of the project.

Analysis of the characteristics of the hydrocarbons from data acquired during the drilling of the Speculant exploration will mean the installation of a new pipeline between the Croft well site and the Heytesbury gathering facility is required, Mr Gray explained.

“We are aiming to commence construction toward the end of spring 2015 and we’re currently undertaking submission reviews following a selective tender process,” he said.

The existing pipeline will remain suspended and be subject to regular maintenance inspections, pending future decisions.

In regards to the company’s BassGas Mid Life Enhancement project in the offshore Bass basin, Origin is completing drilling operations on wells five and six, which when brought online will extend the life of the BassGas project for several years, according to Mr Gray.

“Looking ahead, there are several other opportunities in the Bass basin that might be pursued to further extend the life of this project,” he said.