United States Oil (NYSE: USO), the exchange traded fund for the industry is down for the last week of market action.  So is United States Natural Gas (NYSE: UNG), the exchange traded fund for natural gas.  That was almost sure to happen as short term factors such as cold weather in the United States and the crisis in the Ukraine took the prices higher.  For long term investing, this is an opportunity to buy oil and natural gas entities ranging in size from BP PLC (NYSE: BP) to Mondial Ventures (OTC: MNVD) at a discount.

Long term the future is very bullish for oil and natural gas firms.

As detailed in a recent article on this site, the crisis in the Ukraine is showing the long term value of oil.  It is being used more and more as a safe haven asset.  Traditionally, that has been gold.  The exchange traded fund for gold, SPDR Gold Shares (NYSE: GLD), has done well, too, thanks to tension in the Ukraine.  It has also resulted in a bullish outlook for publicly traded companies in the sector ranging from Goldcorp (NYSE: GG), one of the biggest, to Premium Exploration (OTC: PMMEF), a promising small cap.

Part of the reason that oil and natural gas has pulled back is that it has done so well in recent trading.

BP PLC is up nearly 25 percent for the last year of market action (chart below).  It just got approval to go after Federal contracts again in the United States. Eventually, BP will leave all its legal woes behind that have resulted from the tragic accident in the Gulf of Mexico.  With global operations, it is well positioned to gain from growth abroad.

After that, the long term demand for oil and natural gas from around the world will lift up the share prices of United States Oil, BP PLC, Mondial Ventures, United States Natural Gas, and other securities in the sector.