OMV confirms COSL Prospector for GSB drilling
By Gavin Evans
July 5 (BusinessDesk) - OMV has confirmed its selection of the COSL Prospector to drill in the Great South Basin this summer.
The firm has contracted the four-year-old harsh environment rig for only one well off the South Island – the Tawhaki-1 well, about 146 kilometres off the coast south-east of Balclutha.
The rig is currently being used for a development drilling programme in the Tui oil field off the Taranaki coast. That is expected to be concluded by late October.
It will then be used by OMV and its partners for a three-well exploration campaign off Taranaki. The location of those wells hasn’t been publicly confirmed.
OMV and partner Mitsui have been exploring in the Great South Basin for 12 years but are yet to drill a well. Their 16,715 square-kilometre permit, extended by the government last year, expires in July 2022 and requires the drilling of a well by July 2021.
If that drilling is successful the permit can be extended out to 2030, but would also require the drilling of two further wells by July 2022.
The Environmental Protection Authority will consider OMV’s detailed drilling plans off the South Island without public input.
But a technical anomaly in the legislation policing the country’s Exclusive Economic Zone means it will hold a public hearing in Dunedin later this month to consider one aspect of it – the potential for immeasurably small trace quantities of potentially harmful substances that may – if spilled – end up washing off the deck of a drilling rig through its rainwater run-off systems.
OMV operates the offshore Maari oil field and the Pohokura and Maui gas fields. In the past 20 years it has invested more than $2 billion in New Zealand and has paid more than $1 billion in taxes and royalties. Earlier this year it announced a $500 million programme to redevelop the Maui and Pohokura fields.
In evidence lodged with the EPA this week, Gabriel Selischi, the firm’s senior vice-president for Asia-Pacific, said the discharge consent is only a minor component of the broader exploration and appraisal drilling – EAD – programme the firm is planning in the Great South Basin.
While there is no economic benefit derived from the discharge application “the overarching EAD programme will provide substantial economic benefits to New Zealand,” he said.
OMV’s discharge application is for the potential life of the permit out to 2030. The company has signalled that, if the initial drilling is successful, a further nine wells could be possible during the rest of that period – two further exploration wells and up to seven appraisal wells.
With the rig now confirmed for the first well, evidence was provided that the most ecotoxic substance expected to be on board is the chlorine bleach used to purify the vessel’s drinking water supply.
While that is more toxic than a corrosion inhibitor OMV had used in the modelling for the environmental impact assessment it lodged with the EPA, the environmental risk from a small spill into the deck drainage would still be negligible given the large and rapid dilution of those discharges in the receiving environment, Reid Forrest, a marine scientist and associate consultant for SLR Consulting, said.