2014 due to high inventories and excess crude supply in the U.S. market.

A differential in crude oil prices exists between high-quality (high-gravity, low-sulfur) crudes and those of lower quality (low-gravity, high-sulfur). The amount of the differential in any period is associated with the supply of heavy crude versus the demand, which is a function of the capacity of refineries that are able to process this lower quality feedstock into light products (motor gasoline, jet fuel, aviation gasoline and diesel fuel). After peaking early in second quarter 2014, the differential has eased in North America as refinery crude runs remained at or above record levels. Outside of North America, easing of geopolitical tensions and continued expansion of supply of light sweet crudes has pressured light sweet crude prices relative to those for heavier, more sour crudes.

Chevron produces or shares in the production of heavy crude oil in California, Indonesia, the Partitioned Zone between Saudi Arabia and Kuwait, Venezuela and in certain fields in Angola, China and the United Kingdom sector of the North Sea. (See page FS-11 for the company’s average U.S. and international crude oil realizations.)

In contrast to price movements in the global market for crude oil, price changes for natural gas in many regional markets are more closely aligned with supply-and-demand conditions in those markets. Fluctuations in the price of natural gas in the United States are closely associated with customer demand relative to the volumes produced and stored in North America. In the United States, prices at Henry Hub averaged $4.28 per thousand cubic feet (MCF) during 2014, compared with $3.70 during 2013. As of mid-February 2015, the Henry Hub spot price was $2.73 per MCF.

Outside the United States, price changes for natural gas depend on a wide range of supply, demand, regulatory and commercial factors. In some locations, Chevron is investing in long-term projects to install infrastructure to produce and liquefy natural gas for transport by tanker to other markets. The company's contract prices for liquefied natural gas (LNG) are typically linked to crude oil prices. Chevron's international natural gas realizations averaged $5.78 per MCF during 2014, compared with $5.91 per MCF during 2013. (See page FS-11 for the company’s average natural gas realizations for the U.S. and international regions.)

The company’s worldwide net oil-equivalent production in 2014 averaged 2.571 million million barrels per day. About one-fifth of the company’s net oil-equivalent production in 2014 occurred in the OPEC-member countries of Angola, Nigeria, Venezuela and the Partitioned Zone between Saudi Arabia and Kuwait. OPEC quotas had no effect on the company’s net crude oil production in 2014 or 2013. At their November 2014 meeting, members of OPEC supported maintaining the current production quota of 30 million barrels per day, which has been in effect since December 2008.

The company estimates that oil-equivalent production in 2015 will be flat to 3 percent growth compared to 2014. This estimate is subject to many factors and uncertainties, including the duration of the low price