- Shares in Nostra Terra Oil & Gas [LON:NTOG] fell after it announced that drilling had begun on its initial vertical pilot well in the Bale Creek prospect in Oklahoma.

Nostra Terra has a 30% working interest in the prospect.

Following the completion of the seismic interpretation, final selection of the drill sites was made, and site work began.

The vertical pilot hole will be drilled and logged to determine the most promising of all the potential productive zones.

Drilling of the well is expected to be completed in approximately 30-days, depending on logging and possible formation tests.

Nostra Terra will make further announcements as the operations progress.

Egdon Resources [LON:EDR] has agreed the farm-out of a 12.5% interest of its licence in Leicestershire to Terrain Energy and Corfe Energy.

Terrain and Corfe will each pay 12.5% of the cost of the planned Burton on the Wolds-1 exploration well to earn a 6.25% interest.

As a result Egdon's exposure to the well is reduced from 50% to 25% up to an agreed well cost.

Terrain and Corfe have also agreed the same terms with Celtique Energie Petroleum Ltd. On completion the licence interests in Petroleum Exploration and Development Licence 201, will be Egdon Resources UK 37.50% (operator); Celtique Energie Petroleum 37.50%; Terrain Energy 12.50% and Corfe Energy 12.50%.

The transfer of interests is subject to the approval by the Department of Energy and Climate Change.

Xcite Energy [LON:XEL] has announced an upgrade to the Bentley field's 1P, 2P and 3P oil reserves to approximately 96 million, 116 million and 140 million barrels respectively.

These reserves are estimated to be worth $1.076bn, $1.464bn and $1.921bn on a 1P, 2P and 3P basis, respectively.

Chief executive Richard Smith said: "The upgrade to 116 MMstb of 2P reserves for the core area on the Bentley Field is independent confirmation that Bentley is a major North Sea asset.

"Furthermore, the Bentley Field is expected to contain significant upside potential from future appraisal of the non-core area prospects, as well as the application of enhanced oil recovery techniques.

"We now look forward to a successful delivery of Phase 1A on Bentley expected later this year."

Gulf Keystone [LON:GKP] has confirmed that it still intends to move from AIM to a a premium listing on the Official List of the London Stock Exchange during this year.

The company said that further to recent present comments, it continued to work with its advisers to undertake the move which was announced on 14 September.

The company's said its current intention remains to undertake the move during 2012, subject to obtaining the necessary approvals.

The sector's biggest riser was Max Petroleum [LON:MXP] - up by more than 27% in late afternoon trading - while the biggest faller was Petroneft Resources [LON:PTR] - down by nearly 10%.

At 4:06pm:

[LON:AUR] Aurum Mining share price was +0.01p at 3.38p

[LON:BOR] share price was +5.5p at 80.75p

[LON:CHAR] share price was +11.5p at 167.25p

[LON:DES] Desire Petroleum share price was +4.5p at 35.25p

[LON:DGO] Dragon Oil share price was +13.25p at 560.25p

[LON:EDR] Egdon Resources share price was -0.25p at 12.75p

[LON:ENQ] share price was +2.15p at 120.75p

[LON:FOGL] Falkland Oil and Gas Limited share price was +6.88p at 68.63p

[LON:GKP] Gulf Keystone Petroleum share price was +17.38p at 428.38p

[LON:GPX] share price was +2.5p at 173.5p

[LON:INDI] share price was 0p at 907.5p

[LON:MXP] share price was +3.13p at 14.13p

[LON:NTOG] share price was -0.01p at 0.42p

[LON:PET] Petrel Resources share price was -0.25p at 7.63p

[LON:RKH] share price was +13.25p at 384.5p

[LON:RPT] Regal Petroleum share price was 0p at 29.75p

[LON:XEL] share price was +0.75p at 155.25p

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