New Method for Calculation of Dynamic Reserves in Water Drive Gas Reservoir by Considering Watersealed Gas
Tang Chuan ,Zhao Jiahui(Southwest Petroleum University,Chengdu,Sichuan,610500,China) Zhang Junsong (Sichuan Petroleum Administration Bureau Downhole Services Company,Deyang,Sichuan,618000, China) Zhao Wenjuan (PetroChina Sichuan Luzhou Marketing Company,Luzhou,Sichuan,646666,China) Zhang Jie(Sichuan Petroleum Administration Bureau Well Cementing Company,Deyang,Sichuan,618000,China)
During water influx of active water drive gas reservoir,water will quickly channel along fractures or invade across them and separate part of the gas reservoir from each other. For gas encircling and sealing phenomenon, established is a material balance equation which considers gas sealed bywater and combined is automaticfittingmethod’s optimization algorithm and obtained is a newmethod for calculating dynamic reserves and water influx of water drive gas reservoir. The new method is able to directly calculate the water drive gas reservoir’s dynamic geological reserves,gas volume sealed by water and water influx through fitting the formation pressure data and water drive strength index can be determined by using the method. Comparative analyses on results obtained respectively by using this new method, pressure drop method and water drive gas reservoir’s curve-fitting method shows that the new method is accurate and reliable.