Monthly Drilling Overviews 2009-2011 and an overview of wells drilled from 1935 - 2011
Wells drilled in the subsoil can generally be categorized as follows:
Exploration and appraisal wells drilled by the oil companies to investigate whether a mapped structure contains oil and gas, and, in the affirmative, to determine the size of the accumulation.
Development wells drilled to recover oil and gas from the accumulations. This group of wells comprises both production wells and injection wells. Injection wells are used to inject water or gas into the fields to drive the oil towards the production wells.