Upstream activities cover exploration and production of oil, gas, and geothermal. The aim of exploration activities is to discover new oil and gas reserves as a replacement of hydrocarbon that has been produced. This effort is intended to maintain the production continuity. The exploration and production activities are performed through its own operation and joint operation arrangements.

The business partnership forms are JOB-EOR (Joint Operating Body for Enhance Oil Recovery), JOB-PSC (Joint Operating Body for Production Sharing Contract), TAC (Technical Assistance Contract), Consortium Cooperation System, IP (Indonesian Participation), PPI (Pertamina Participating Interest) and project loan. While for the geothermal sector, the business partnership is JOC (Joint Operating Contract) arrangement.

The company has concession block operated as own operation arrangement covering 7 (seven) oil and gas Operation Area , i.e. Nangroe Aceh Darussalam (NAD) Northern Sumatra Operation Area with the main office in Rantau, Central Sumatra Operating Area with the main office in Jambi, Southern Sumatra Operation Area with main office in Prabumulih, Western Java Operation Area with main office in Cirebon, Eastern Java Operation Area with main office in Cepu, Kalimantan Operation Area with main office in Balikpapan, and Papua Operation Area with main office in Sorong. There are 3 geothermal producing areas with the 162 MW installed capacity owned by Pertamina. Those areas are : Sibayak (2 MW) located in North Sumatra, Kamojang (140 MW) located in West Java and Lahendong ( 20 MW) located in North Sulawesi. Pertamina markets its fuel products for fulfilling the demand from industry, bunker, land transportation and domestic consumption. Pertamina lubricant has Lube Oil Blending plant (LOBP) in Jakarta, Surabaya and Cilacap with total capacity of around 573,000 kilo liter per year (2 shift/day). Pertamina lubricant is consumed by industrial engine, automotive engine, marine engine etc. Pertamina has come to be the market leader of Indonesian lubricant. Pertamina Upstream has 64 oil and gas contracts of joint operation arrangements. They consist of 6 partnership under JOB-EOR contract systems, 12 partnership under JOB-TAC contract systems, 34 partnership under TAC contract systems, 1 partnership under Consortium Cooperation System, 3 project loans, and 8 partnership under IP/PPI contract systems. Meanwhile there are 8 Joint Operating Contracts for geothermal exertion.

Among 64 of oil and gas contracts within the joint operation arrangement, 30 contracts are in the commercial-producing stage and the other areas are still in the exploration stage.

To develop its exploration and production business, Pertamina Upstream has made a step forward through strategic alliances with domestic and foreign partners. Pertamina Upstream has prospective business in oil and gas drilling services called Pertamina Drilling Service (PDS), which owns 28 drilling-rig units.

In the gas transmission business, Pertamina Upstream has 3800 km total length of gas pipeline and 64 compressor stations.