Abstract: Recovery factor of condensate oil in condensate gas reservoir with water developed by natural depletion is affected by many factors and hard to forecast. Considering the production performance of Pinghu gas reservoir in Pinghu field, this paper proposes four methods for prediction of its recoverable reserves, such as empirical formula method, material balance method, performance decline method and numerical simulation method. The prediction results show that these four methods are all practicable in application. In view of specific condition, one of these methods can be selected to use and/or several methods are applied for comprehensive evaluation of such a reservoir.

Key words: Pinghu field, condensate oil, recoverable reserve, condensate gas reservoir, prediction, forecast