Resource uncertainty categories; Reserves Classification; Resource classification

Any estimation of resource quantities is subject to uncertainty and should thus be expressed as a potential range. The function of the three primary categories of reserves (proved, probable, possible) is to illustrate the range of uncertainty in the estimate of the potentially recoverable volume of petroleum from a known accumulation. Such estimates, which are …

Return on equity, return on capital employed (oil and gas companies)

Traditional measures of profitability. Profit returns divided by the volume of resources devoted to the activity. Although oil and gas companies’ profits have risen to record highs as the price of oil has soared, their profitability as measured by return on capital employed has stagnated. In the upstream side of the business average return on …

Revenue sharing contract

These are very similar to the production sharing contracts, with the exception of contractor payment. With these contracts, the contractor usually receives a defined share of revenue rather than a share of the production. As in the production-sharing contract, the contractor provides the capital and technical expertise required for exploration and development. If exploration is …

Rock cycle

All rock at or near Earth’s surface is being modified by the processes of metamorphism, melting, crystallization, lithification and weathering. These processes move rock material through the states of metamorphic rock, igneous rock, sedimentary rock, melts and sediments. The natural and continuous cycling of rock material through these states is known as the rock cycle