Research on Productivity Characteristics and Correction of Productivity Equations of Gas Wells in Fractured Gas Reservoirs
Fractured gas reservoirs are characterized by abundant reserves and high gas well productivity.The binomial pro-ductivity equation of conventional theory has bad applicability in fractured gas reservoirs,and the turbulence flow coefficient obtained by theoretical model is far less than the measured results.Taking Keshen Gas Field as an example,we summarize natu-ral gas production characteristics in fractured natural gas reservoirs based on geological cognition,test data,percolation theory and numerical simulation.The analysis results show that intersection of wellbore and natural fractures is the main production well section,and the accumulation of gas in natural fractures increases the turbulence effect during production,resulting in obvious high-speed non-Darcy effect,and the theoretical binomial productivity equation cannot accurately evaluate its produc-tivity.Secondly,the binomial productivity equation correction method for fractured gas reservoirs is established by regressing the relationship between the theory of Keshen Gas Field and the actual non-Darcy flow coefficient.The reliability of the pro-ductivity model is verified by the measured data.The case analysis shows that most of the energy consumed in the production process of Keshen gas well is turbulent effect,so it is necessary to control production for reducing pressure loss in fractured gas reservoir.Finally,the calculation value of production is tested with the single-point productivity formula.The computed result shows that the gas well productivity calculated under the condition of low production pressure difference is much higher than the actual results,and the reasonable test production pressure difference should be between 4％and 10％of the formation pressure.
fractured gas reservoirgas well productivitycorrection methodturbulence effectpercolation theory
万方数据
维普
