Oil prices have remained range bound this week, and Brent crude for January delivery has gained just 0.8% to $107.36 per barrel since Monday, while WTI crude was up by 0.3% on the week at $86.15 per barrel shortly after U.S. markets opened on Friday. U.S. natural gas prices have weakened once more, and gas for January delivery was down by 5.9% on the week at $3.29/mmbtu shortly after 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 (USO -2.98%) have seen their shares gain a modest 0.1% so far this week, leaving them trading at $31.56 shortly after the open on Friday. Falling natural gas prices have pared 7.1% from the United States Natural Gas Fund (UNG -0.69%) so far this week, leaving the stock trading at $18.76 shortly after U.S. markets opened on Friday.

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.

Gulfsands Petroleum (LSE: GPX) has soared 24% to 98 pence this week. The company, which owns substantial oil production assets in Syria, has not released any news but has become a direct play on the chances of an orderly resolution to the civil war in Syria. Gulfsands' operations in Syria have been suspended for most of 2012, but the company has $100 million in cash so can afford to wait for the situation to resolve, assuming its Syrian installations remain intact.

Tullow Oil's (TLW -1.30%) share price has recovered 3.5% to 1,119 pence since Wednesday, after falling heavily following two disappointing drilling updates over the last fortnight. Tullow's reputation has been built around high-impact exploration success and its run of poor results has disappointed investors. However, the FTSE 100 (UKX) company has also acquired some new North Sea prospects and its share price is now 17% lower than three months ago, presenting a possible buying opportunity for investors who believe the company's story is intact.

Rockhopper Exploration (RKH 2.16%) has climbed 6.3% to 158 pence this week, suggesting that investors are beginning to look at this stock in a new light. The company's half-yearly report, published today, emphasizes the progress that has been made this year. Rockhopper remains the only Falkland explorer to have found oil and now has a strong partner, Premier Oil, to develop this find. Rockhopper also has $231 million cash in hand to appraise further exploration prospects.

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