PT Pertamina Hulu Kalimantan Timur Daerah Operasi Bagian Utara (PHKT DOBU) is company of exploitation and production crude oil and natural gas to meet energy needs in Indonesia. Activities of exploitation and production of crude oil and natural gas will produce pollutants which become a source of pollution for the environment. Therefore, it is necessary to conduct an environmental impact study using the Life Cycle Assessment (LCA) method. LCA is a method for analyzing environmental impacts across all units of a company process to produce a product. The method used to categorize the impact on the LCA study is ReCipe 2016 at the midpoint and endpoint levels with the SimaPro application. Environmental impact assessment with LCA shows that the production process of 1 ton natural gas contributes a greater impact is 60.59 Pt than the production process of 1 ton crude oil, which is 9.18 Pt, with the most dominant environmental impact being fossil resource scarcity.