26-06-08 Total's phenomenal long run of luck in the North Sea continued with the discovery, announced just this month, of a new gas condensate in the Alwyn Area of the Northern North Sea. The field, now named Islay, lies in block 3/15 of the UK sector, some 440 km north-east of Aberdeen in a water depth of 120 meters.
Commenting on the find, Paul Mason, new business manager at Total E&P UK, points out that since the Alwyn Dunbar discoveries were first made in the 1970s, and brought on stream in the 1980s, a string of discoveries has kept the gas plant full.
"Now, 21 years later, we have to de-bottleneck the gas plant to give it more capacity," he says.

In addition to its recent Jura discovery, which went into production within a record 17 months, Total's finds include West Franklin, Forvie North and Tormore. What has made the latest discovery possible is the huge strides made in seismic technology.
"The technology has moved on fantastically since the days of two-dimensional (2D) line-based seismic reports," says Mason. "No-one at that time thought that 3D seismic would be possible because of the huge computing power it would require to drive it."

However, 3D has now come along and Total has been able to revisit its massive data sets and look at old and new seismic material with eyes that could give it a much higher degree of resolution and detail.
"We can now see structures at 4,000 meters beneath the surface. Jura, the field we announced first gas from on 20 May this year, is located at around 100 meters from the surface and so we found it rather more readily. However, when we applied the 3D technology, our geologists could see a nice big structure, like a stack of dominoes, which is exactly what you are looking for, and our well on Islay proved positive at 4,000 meters."

Islay will be another High-Temperature, High-Pressure field (HTHP) and the initial worry for Total was whether it would be able to retain its reservoir properties, with the right porosity, despite the high pressuresinvolved.
"Basically, at that sort of depth, you get a lot of pressure on the rock and, in the race for space, with cements and pressure trying to close up the porosity, you can lose out," Mason says. "In fact, the test well answered this question positively, showing that the reservoir was able to maintain its good characteristics at that depth."

During testing, the well produced 1.22 mm cm of gas a day. Total is already the 100 % owner and operator of the Alwyn North, Dunbar, Grant, Ellon, Nuggest, Forvie North and Jura fields. Total will now develop a plan to connect the well, which is just three km east of its Jura field, to the Alwyn facility.
Mason reckons that with its increased understanding of the "deep play" game on the giant Brent province, Total is optimistic about future exploration wells which will follow the Islay find.

Turning to Jura, Mason points out that the significance of this discovery, now in production, is that it holds some 170 mm barrels of oil equivalent. This is substantially more than the average discoveries in the North Sea in recent years.
"The average size of discoveries in 2005 and 2007, for example, was just 10 mm barrels of oil equivalent," he points out. The scale in 2006 was a bit better at 20 mm. But by comparison a 170 mm field is huge.

Mason says that, of itself, Jura underwrites the continued viability of the Alwyn infrastructure.
"We are in the 21st year of production on Alwyn and there is no reason why it should not go on for another 20 years yet," he comments.

Total reckons that the structure it is seeing in the rest of the block, a tilted fault rock just stepping down into the Viking Graven arena, is very promising.
"You are looking for Jurassic Tilted Fault Block," Mason says. When the geologists see this they get excited and they have plenty to interest them in the area."

However, to be certain there is anything of commercial viability down there, the company has to drill and drilling is a huge gamble. It's not surprising to find a test well coming in at upwards of £ 50 mm.
"A number of companies in this industry have run three or four dry wells and exhausted their resources," says Mason. "We, on the other hand, have had a really lucky streak with discoveries and we have been lucky, too, in that we have made discoveries in areas where there is the infrastructure to bring the oil to shore."