Estrella International Energy Services Ltda.

Chevron is one of the world's leading integrated energy companies and conducts business worldwide. Our success is driven by our people and their commitment to get results the right way—by operating responsibly, executing with excellence, applying innovative technologies and capturing new opportunities for profitable growth. We are involved in virtually every facet of the energy industry. We explore for, produce and transport crude oil and natural gas; refine, market and distribute transportation fuels and lubricants; manufacture and sell petrochemical products; generate power and produce geothermal energy; provide energy efficiency solutions; and develop the energy resources of the future, including research for advanced biofuels.

Halliburton Co. engages in the provision of services and products to the energy industry related to the exploration, development, and production of oil and natural gas. It operates through the following segments: Completion & Production, and Drilling & Evaluation business segments. The Completion and Production segment delivers cementing, stimulation, intervention, pressure control, specialty chemicals, artificial lift, and completion services. The Drilling and Evaluation segment provides field and reservoir modeling, drilling, evaluation, and wellbore placement solutions that enable customers to model, measure, and optimize their well construction activities. The company was founded by Erle P. Halliburton in 1919 and is headquartered in Houston, TX.

Occidental Petroleum Corporation (NYSE: OXY) is an international oil and gas exploration and production company with operations in the United States, Middle East and Latin America. Headquartered in Houston, Occidental is one of the largest U.S. oil and gas companies, based on equity market capitalization. Occidental's midstream and marketing segment gathers, processes, transports, stores, purchases and markets hydrocarbons and other commodities. Occidental's wholly owned subsidiary, OxyChem, is a major North American chemical manufacturer.Occidental's success is built on technical expertise, business acumen, strong partnerships and proven ability to deliver lasting results. With approximately 35,000 employees and contractors worldwide at year-end 2015, they are committed to being a Partner of Choice® everywhere they operate. Occidental is committed to respecting the environment, operating safely and upholding high standards of social responsibility throughout the company's worldwide operations.