Methods of Calculating Recoverable Reserve in Heavy Oil Reservoirs Developed by Steam Injection

摘要

This paper develops methods of calculating recoverable reserve under steamflooding. It is based on reservoir engineering, geology and development conditions. A series of calculating methods have been established for various development situations, patterns, and stages. From the principle of combining perfect screening with innovative ideas, waterflooding characteristic curves commonly applied to light oil are applied to steamflooding viscous oil. The following 6 methods have been suggested which are suitable to the development characteristics of steamflooding viscous oil: numerical analogy, empirical formula, injection-production characteristic curve, decline curve of oil-steam ratio, production progressive rate and production decline rate. The feasibility of these methods have been further verified through the example studies of block Huan 60 not developed yet, block Du66 exploitated by steam stimulation, and block Shul-7-5 opened up, by steamflooding.