Evaluation Of Development Potential Of Volatile Reservoirs In Offshore Fault Block Oilfield

The volatile oil is usually liquid in the reservoir,its properties are between the condensate gas and the black oil.The development procedures of volatile reservoir s are significantly different from black oil reservoirs,because of the differences between theirs..There are lots of difficult problems during the development of the volatile reservoirs in C oilfield:the gas-oil ratio decreases after the formation pressure lower than the saturation pressure;the cognition of the fluid phase patten is unreliable,because the fluid samples are not enough to represent others;it is necessary to further enhanced oil recovery because of the lower recovery.In this paper,through the research and analysis of reservoir fluid properties,reservoir development dynamic characteristics,reservoir production history matching,etc.,the development potential of existing reservoirs is evaluated,the feasibility of the south block is analyzed,the production scheme and the reasonable working system are formulated,the production effect is predicted.According to the fluid composition,fluid properties and fluid P-T phase diagram,it is determined that the well fluid has obvious volatile fluid characteristics,and the reservoir belongs to the volatile reservoir.The analysis of production performance shows that the decrease of gas-oil ratio in volatile reservoir of C oilfield is the result of the combination of non-equilibrium phase transition,secondary gas cap,component gradient and other factors;oil edge water energy is weak.Using numerical simulation software,using liquid volume simulation,considering fault connectivity,comprehensive analysis of component gradients,non-equilibrium phase transition and other factors,the historical matching results of oil formation are obtained.Combined with the analysis of production performance,geological and numerical simulation results,it is concluded that the internal fault of the reservoirs is sealed and the south block has great potential for production.It is recommended to adopt"depletion development" that the development method of the south block of the volatile reservoirs.The designed directional wells and horizontal well development schemes can achieve high recovery.