Page 86: of Offshore Engineer Magazine (Aug/Sep 2016)

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REGIONAL OVERVIEW

Northwest Europe

REGIONAL OVERVIEW

Leaving no rock

Elaine Maslin examines new UK government funded seismic shoots and data reprocessing, all free to the industry, which are among unturned initiatives aimed at boosting UK

Continental Shelf exploration. hile exploration has been dwelling at historic lows Rockall Trough on the UK Continental Shelf (UKCS), a scheme to The Rockall Trough and Mid North Sea High were chosen be-

W open up underexplored areas of the basin could yet cause they’re underexplored. Fiona Legate, senior analyst, UK turn the trend around. Upstream Oil and Gas, Wood Mackenzie, says only Austria’s

The UK’s still relatively new Oil and Gas Authority (OGA) OMV, an integrated oil and gas ? rm, and independent min- was given government funding to shoot seismic over the now Parkmead, have acreage in the Trough.

Mid North Sea High, in the central North Sea, and the north According to PGS, the Rockall Tough has fewer than 10

Rockall Trough, west of Scotland, last year, supported by wells per 1000sq km. Newcombe says that only two discov- legacy data reprocessing. Both are being used to decide what eries have been made in the Rockall area: Dooish, on the th will be offered in the 29 licensing round, which was due to edge of the Trough in the northern Irish Rockall Basin; and open early August. Further, the OGA is eyeing yet more new Benbecula, in the northeast Rockall Basin in the UK sector. seismic acquisition in areas of western Britain and the East Legate says that six exploration wells have been drilled in the

Shetland Platform this year. Rockhall Trough itself to date, largely in the 1980s and 1990s,

Gunther Newcombe, director of exploration and produc- and all were dry holes. tion at the OGA, and a geologist by education, thinks there’s Some of the challenges in the Rockall are deeper waters, a lot that has been overlooked in the basin. “People call the but also Basalt intrusions, which make mapping of migration area [North Sea] mature, even super mature, which is true for complex. “It is deepwater and there has been a lack of data,”

Newcombe says. “There was a survey in 2014 by BP with some areas. But, some mature areas, like the southern North (British Geological Survey) study on the northern North Sea better de? nition. It was the ? rst shoot in that area. We now Sea, still have potential. Carboniferous tight gas has a lot of Paleozoic. This will give people greater insight.” have 10,000sq km [in the area and] from that it will be hard to potential, for example.” The new data is giving companies the opportunity to look de? ne a prospect to drill. But it can show the play potential in To shine a light on these underexplored areas, the OGA has at deeper horizons, he says. The BGS survey on the northern order to do more seismic.” spent £20 million (US$26 million) of government funding on North Sea Paleozoic is also letting people see where plays ex- new 2D seismic data. tend into the onshore, from which they can extrapolate back

Mid North Sea High

The new seismic was shot by WesternGeco, covering to the offshore. 200,000sq km of the UK Continental Shelf. What’s unique is Unlike the Rockhall Trough, there are quite a few acreage

Licensing round that it, and the 20,000km of legacy data, is being made freely holders, including majors and independents, in the Mid North

Sea High. But still, it has been described as “one of the last re- available to the industry – in processed and unprocessed The Rockall Trough and Mid North Sea High will feature th maining underexplored areas of the UKCS” by geoscience ? rm form. Furthermore, some of the legacy data are lines that heavily in the 29 licensing round, a round likely to be light

Polarcus, with a possible Devonian-Carboniferous petroleum can no longer be shot again, due to ? shing gear now in the on license commitments, Legate says. Just seven well commit- th system that hasn’t been tested and has been hard to image. area. Some of the 1980s seismic was also shot with dynamite, ments were featured in the 28 round, which closed right at

Legate says that 23 exploration wells have been drilled in which offers a good quality clean source but is no longer used. the start of the oil price crash. With frontier acreage involved, the Mid North Sea High, mostly in the 1960s-1980s. One well The shoot used long offset broadband seismic for lower fewer well commitments can be expected this time round. had gas shows and another oil shows, she says. frequency data, something that has been missing in the past, More likely, data reprocessing or shooting seismic surveys “The Mid North Sea High has in part been explored in the OGA says. Gravity and magnetic data were acquired at the could be expected.

This makes it an opportunity, Legate says. “It is an opportuni- same time. To get the data to the market as fast as possible, past, but it has lacked good quality data for the industry to ty to pick up acreage cheaply with few commitments. Any work onboard processing was carried out from September 2015 to create a deeper understanding of the geology,” Newcombe completed would bene? t from the low cost base we are seeing,

March 2016. By 24 May, some 6000 data packages had been says. Firms have also largely focused on the Permian in the so there is a bit of an opportunity here. What is interesting is the downloaded. past. “We have new data and reprocessed data, plus the BGS

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