Investigation Of The Water Production Effect On Gas Well Productivity In Sulige Gas Field

Along with the development of Sulige gas field,the gas production wells increase as the formation pressure decrease.During the same period of time,the problem of water production in gas wells becomes more and more prominent,and the effect of water production on gas well productivity more and more serious.In order to deepen the understanding of gas reservoir characteristics,gas well productivity characteristics,formation water invasion mode,gas water distribution behavior and gas field water production influence on gas field productivity,researches have been carried out to study the influence of gas production on the productivity in the Sulige gas field.Taking Sulige gas field as the research object,the gas-water phase relative permeability curve of Sulige gas field obtained in the laboratory is analyzed,and the relationship between its characteristic points and permeability is determined.Based on the experimental results,the characteristic points of the relative permeability curve in different permeability ranges are calculated,and the average relative permeability curve of the different permeability ranges is obtained by the normalization method.On the basis of determination of the water production rate,a single well numerical model for the Sulige gas field is established to study the production dynamics of typical gas wells.Based on the history matching results,the gas reservoirs are divided into four types according to different permeability ranges,and the average permeability and formation coefficient of each reservoir type are obtained.Accordingly,the average model of different reservoir type is established,and the production dynamics of typical gas wells in different types of reservoirs are simulated and analyzed.The dynamic characteristics of gas well production under different water sources(side water,bottom water and pore water)are further analyzed through numerical simulation study.And the foundation for the analysis of the source of water production in the actual gas wells in Sulige gas field is developed.In view of the effect of water production on the productivity decline of gas wells,the relationships between unhindered flow rate,productivity decline,water saturation and movable water saturation under different permeability conditions are studied.The research results in this paper are applicable to conduct dynamic analysis of the Sulige gas field.It is also important for efficient development of Sulige gas field.