Producing Oil and Gas

Gas generally flows to the wellbore under its own pressure. As a result, most gas wells are equipped only with chokes and valves to control the flow through the wellhead into a pipeline. When wellhead pressure is less than the pipeline pressure, a compressor is installed to boost the low-pressure gas into the pipeline.

The production of crude oil is more complicated. Crude oil has larger molecules and moves through rocks less easily. The percentage of the oil in the reservoir that can be produced naturally, called the recovery factor, is determined by a large number of elements. These include the density of the oil (how heavy it is), the viscosity (how sticky it is), the porosity and permeability of the rock, the pressure in the oil reservoir, and the pressure of other fluids in the reservoir, such as gas and water.

Petroleum Communication Foundation. Our Petroleum Challenge: Exploring Canada's Oil and Gas Industry, Sixth Edition. Calgary: Petroleum Communication Foundation, 1999. With permission from the Centre for Energy.