Upstream The upstream sector, also known as exploration and production, is the initial phase of oil and gas production. The exploration, drilling, and extraction of crude oil and natural gas all occur in the upstream sector. This sector is crucial as it lays the foundation for the entire oil and gas supply chain, leading to the midstream and downstream sectors. Regal Rexnord supports upstream processes by supplying essential components for upstream applications such as drilling rigs, well servicing rigs, mud pumps, fracking pumps, and more.