Pertamina Hulu Energi ONWJ Ltd is a subsidiary of PT Pertamina (Persero) that operates as an upstream oil and gas company in the North West Java block of the Java Sea, Indonesia. The company focuses on the exploration, production, and management of hydrocarbon resources across an area of approximately 8,300 square kilometers. With operations dating back to 1971, Pertamina Hulu Energi ONWJ has established itself as a significant player in Indonesia's hydrocarbon sector, producing over 1.4 billion barrels of oil and 1 trillion cubic feet of gas from various fields.

The company operates offshore production facilities that include around 670 wells and 170 platforms. It supplies natural gas primarily to the domestic market, serving major customers like PLN, the state-owned electricity company. Pertamina Hulu Energi ONWJ is committed to energy efficiency and sustainability, being the first subsidiary of PT Pertamina to implement the ISO 50001 Energy Management System. The company plays a vital role in supporting Indonesia's energy needs and economic growth through its reliable supply of hydrocarbons.