CLASSIFICATION OF RESERVES AND CONTINGENT RESOURCES OF OFFSHORE OIL AND GAS RESOURCES

According to the needs in exploration and development of offshore oil and gas resources, a standard named “reserves and contingent resources classification of offshore oil and gas resources” is established under the concept of SPE with the characteristics of China's offshore oil industry. As the basis of oil and gas resource classification, discovered oil and gas resources are firstly divided into reserves and contingent resources. Main factors are adopted as the two dimensions for classification. The vertical direction is commercial state and stage for exploration and development of the oil and gas field, while the horizontal direction is the utilization and development status of oil and gas resources. Oil and gas fields are then categorized into oil/gas-bearing structure, evaluating oil/gas-bearing structure, identified commercial oil and gas fields and oil and gas fields on construction or production; Utilization status of oil and gas resources is classified into the used and unused. The used oil and gas include those in production, in plan and in scheme. The unused oil and gas involve in plan unused and in scheme unused; Reserves may be divided into developed and undeveloped, and contingent resources is classified into to be developed and temporarily untapped; Difficult-to-produce reserves include crude oil and natural gas.