Occidental Petroleum Corp. is principally engaged in two industry segments: the oil and gas segment and the chemicals segment. The oil and gas segment explores for, develops, produces and markets crude oil and natural gas. Occidental manufactures and markets basic chemicals, vinyls and performance chemicals directly and through various affiliates (collectively, OxyChem). OxyChem operates chemical manufacturing plants at 26 sites in the United States. Many of the larger facilities are located in the Gulf Coast region of Texas and Louisiana.