Petroleum

Petroleum exploration and production activities are performed primarily by geologists, geophysicists, and engineers. Geologists look for areas of the earth where sediments accumulate. They then examine the area of interest more closely to determine whether or not source rocks and reservoir rocks exist there. They examine the rocks at the surface of the earth and information from wells drilled in the area. Geologists also examine satellite images of large or remote areas to evaluate the rocks more quickly.

Geophysicists examine seismic data, data derived from recording waves of energy introduced into the rock layers of the earth through dynamite explosions or other means, to determine the shape of the rock layers beneath the surface and whether or not traps such as faults or anticlines exist.

Once the geologist or geophysicist has gathered evidence of potential for a petroleum accumulation, called a prospect, an engineer assists in determining how to drill a well or multiple wells to assess the prospect. Drilling a well to explore for petroleum can cost as little as $100,000 and as much as $30,000,000 or more, depending on how deep the well must be drilled, what types of rocks are present, and how remote the well location is. Thus, the scientists must evaluate how much the well might cost, how big the prospect might be, and how likely the scientific predictions are to be correct. In general, approximately 15% of exploration wells are successful.

Once a successful exploration well has been drilled, the oil and/or gas flow are pumped to the surface of the earth through the well. At the surface, the petroleum either moves through a pipeline or is stored in a tank or on a ship until it can be sold.