California processes about 1.8 million barrels of crude oil per day. In 1992, 50 percent of this oil was produced in California; 45 percent was imported from Alaska; and the remaining 5 percent was imported from foreign sources. Crude oil in California is primarily a heavy variety that is extracted by steam injection. New oil sources in the state are limited and prospects for new offshore production are unlikely. California's imports of foreign crude oil have not been large because several refineries have been modified to run efficiently on Alaska North Slope oil. CEC projects increased competition for Alaskan oil with an increase in demand in the western U.S. (PADD V) and declining Alaskan production. Allocation of crude oil production and refinery emissions to the SoCAB depends on whether an incremental gallon of gasoline or the average gallon of gasoline is considered.
Significant fraction of crude oil is produced in the SoCAB, marginal emissions associated with oil production in the SoCAB are estimated to be near zero. Refineries in the SoCAB operate at capacity and demand for additional diesel could be met by importing additional finished diesel. Oil production is estimated to not change with additional demand for diesel fuel as additional product may be imported to California or refinery operations may be modified slightly to produce more diesel and less gasoline.
This assumption does not suggest that the mix of California to imported oil should remain invariant under all conditions, merely that moderate changes in fuel demand will not shift the mix of crude oil sources. The mix of crude oil could change with changing oil prices. If oil prices dropped substantially, for example, more costly oil production in California could be reduced. Crude oil production techniques depend on the demand for oil. Increased use of more energy intensive techniques such as enhanced oil recovery would correspond to higher petroleum prices. The trend in California is to extract more oil through thermally enhanced oil recovery (TEOR). This report does not attempt to predict a change in oil feedstocks or changes in production techniques over the scenarios in this study.
3.4.2 Crude Oil Transport
Oil is transported to the refineries using two primary methods: pipelines and tanker ships. Pipeline emissions result from the pumps that move the oil through the pipelines. Tanker ship emissions are produced by the propulsion and auxiliary engines, which operate on heavy fuel oil. Table 3-7 shows the estimated mix of crude oil and finished petroleum product imports to California. This mix of locations would represent the