Occidental Petroleum (Oxy) is a US oil and gas E&P company and chemical manufacturer. It operates in three business segments: oil and gas, chemical, and midstream and marketing. Oxy engages in oil and natural gas exploration, production and marketing. The chemical segment manufactures and markets basic chemicals, vinyls, and performance chemicals directly or through subsidiaries (known collectively as OxyChem). The company has working interests in Bolivia which are concentrated in four blocks located in the Tarija, Chuquisaca and Santa Cruz regions in the southern and eastern areas of the country. The production, mainly natural gas, is delivered to local state hydrocarbons company YPFB. In addition, Oxy has operations in the Llanos Norte Basin of Colombia's Arauca province and in the Middle-Magdalena Basin in the Santander province. Oxy is based in Los Angeles, US.