Author: bomuo

The first stage of hydrocarbon production, in which natural reservoir energy, such as gasdrive, waterdrive or gravity drainage, displaces hydrocarbons from the reservoir, into the wellbore and up to surface. Initially, the reservoir pressure is considerably higher than the bottomhole pressure inside the wellbore. This high natural differential pressure drives hydrocarbons toward the well and up to surface. However, as the reservoir pressure declines because of production, so does the differential pressure. To reduce the bottomhole pressure or increase the differential pressure to increase hydrocarbon production, it is necessary to implement an artificial lift system, such as a rod pump, an electrical submersible pump or a gas-lift installation. Production using artificial lift is considered primary recovery. Thus, primary recovery produces oil and gas using the natural pressure of the reservoir as the driving force to push the material to the surface

Porosity which is present in sediment at the time of deposition or formed during sedimentation. Compare secondary porosity

The movement of newly generated hydrocarbons out of their source rock, or the expulsion of newly generated hydrocarbons from their source rock (see also gas migration)