LONDON -- Oil prices have remained range-bound this week, with Brent crude on the January contract gaining just 0.7% to $108.87 per barrel since Monday, while WTI crude moved up just 0.1% to $87.99 per barrel over the same period. U.S. Natural gas prices fell hard and gas for December delivery was down by 8.7% on the week at $3.63/mmbtu, shortly before U.S. markets opened on Friday.

Many investors prefer to invest in commodity ETFs rather than directly in futures, and holders of the United States Oil Fund (NYSEMKT:USO) saw their shares close down by 0.46% so far this week at $32.17 on Thursday. The steep fall in the price of natural gas has pushed the United States Natural Gas Fund (NYSEMKT:UNG) to a 9.5% loss so far this week -- the stock closed at $20.81 on Thursday.

The nature of oil and gas companies' businesses means that they can succeed or fail regardless of oil prices. This week's risers have all outperformed the price of oil by a big margin in recent months.

Amerisur Resources (LSE: AMER) has climbed 7% to 47 pence today following news that it has abandoned farm-out discussions for its Fenix block in Colombia and will retain 100% working interest. It also announced that it had begun the acquisition of a 2-D seismic survey covering 59 square kilometers in the southern part of the Fenix block, which adjoins Ecopetrol's productive Bonanza field. The survey is aimed at defining two leads mapped on existing data, which are of a similar style to the Bonanza structure.

Abraxas Petroleum (NASDAQ:AXAS) has gained 23% to $2.24 since Monday. The company has had a burst of news flow this week; following a positive operations update on Nov. 27, details emerged of a letter sent to the board by leading shareholder Clinton Group, demanding a number of changes to the company's activities, aimed at unlocking the intrinsic value of Abraxas' assets and reducing its debt. Clinton Group's view is that the fair value of the stock is $4.35 -- double its current price. Abraxas followed this on  Nov. 28 with updated guidance for 2013 production, which it expects to be approximately 21%-28% higher than 2012.

Desire Petroleum (LSE: DES) is up 7% to 22 pence this week, after publishing an updated Competent Persons Report covering its North Falkland Basin prospects. The report included the results of a new 3-D seismic survey and indicates total best case unrisked prospective oil and gas resources of 2.45 billion stock barrels and 274 billion cubic feet respectively. Ten prospects have a chance of success of 30% or better.

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