An Aberdeen-based independent exploration company has discovered a major ‘new’ gas field in the North Sea.
Privately-held Arenite Petroleum Ltd has identified the Maxwell field off Scarborough after re-evaluating historic well and seismic data with joint venture partner Europa Oil and Gas.
When first drilled by Total over 40 years ago, five wells flowed gas at high rates (three of those wells flowed over 15 million standard cubic feet of gas per day) – but were viewed at the time as not economically recoverable.
In 1991, Conoco, the US independent oil company, drilled a further well which flowed at 34 million standard cubic feet of gas a day and 1,230 barrels of condensate per day from fractured Permian carbonates. At the time, companies considered the gas finds small and subsequently relinquished their licences.
However, Arenite – which is based in Westhill -has now completed a detailed re-evaluation using advanced seismic imaging techniques, coupled with industry experience in analogue gasfields where ‘game-changing’ horizontal drilling and well completion techniques have redefined commerciality.
Arenite’s mapping reveals a huge accumulation in naturally fractured Permian-aged carbonate rocks a few miles offshore, with ‘vast’ underlying carboniferous potential.
Mike Cooper, Director and Founder off Arenite Petroleum, explained: “We’ve name this accumulation the Maxwell gasfield. It is a giant gasfield which has been hiding in the open, analogous to the realisation made many decades ago that a series of small gas discoveries in the Netherlands were indeed part of the giant Groningen gasfield – now the largest onshore gasfield in NW Europe.
“While the sustainable production rates at the Maxwell gasfield are yet to be established, with state-of-the-art drilling, completion and production techniques, we believe commercial deliverability can be achieved.
“The old exploration wells experienced significant challenges with high formation pressures, which caused drilling problems and yielded anomalous results when flow tested.
“We now understand that the sequence of rocks these wells drilled through were over-pressured due to there being an extensive gas column, producing high pressures at relatively shallow depths.
“This phenomenon is now well understood and can be managed using appropriate drilling techniques.”
The area is known to hold huge potential in both shale gas and tight sandstone strata throughout northern England, as reported in the BGS/DECC Bowland Shale gas study.
Indeed, to the west of Arenite’s acreage, Third Energy produce onshore from naturally fractured Permian carbonates at Ryedale and are planning to test the Carboniferous at Kirby Misperton later this year.
Offshore BP have commenced drilling a proof-of-concept well to test the Carboniferous beneath the producing Ravenspurn gasfield. The latter well operation is projected to cost at least £100 million to drill and conduct a long-term test.
Cooper added: “Drilling at Maxwell will cost a fraction of this sum. Egdon Resources are planning a 2017-18 well immediately north of Arenite’s acreage on their Resolution discovery, which is one of the structural culminations of the bigger Maxwell gasfield.
“We firmly believe producing the high-pressure gas is the best way to enable safe future offshore mining operations. The flow rates that have been achieved offshore would almost certainly overwhelm a mining operation.
“The problem area is east of a series of major geological faults which trap the gas before it gets onshore. One of this array of geological faults can be clearly seen beneath the wall of Scarborough Castle (the Peak Fault).”
Arenite is now seeking investors to drill a proof of concept horizontal well into the Permian carbonates (with two major target horizons identified) and deepen this well to test the underlying Carboniferous strata.