Research And Application Of Production Performance Evaluation Index Of Fracturing Horizontal Wells In Tight Gas Reservoirs

With the rapid growth of global demand for natural gas resources and the deepening of exploration and development of oil and gas resources,more and more countries are paying attention to the development of tight gas reservoirs.The researchers at home and abroad in view of the tight gas reservoir fracturing horizontal well production performance evaluation was carried out by a lot of research,this article on the basis of literature research study,to carry out the tight gas reservoir fracturing horizontal well production decline rate and productivity index method for determining the dynamic index,to evaluate the dense gas reservoir fracturing of horizontal well production performance with practical means.At first,this paper established a dense gas reservoir fracturing of horizontal seepage physical model,the further application of seepage theory established the dense gas reservoir fracturing of horizontal composite area unstable seepage flow mathematical model,solving the mathematical model,this paper analyzes the model of bottom hole pressure and its derivative curve characteristics,and evaluate the influence factors of the curve.The results show that derivative curve characteristics of bottomhole pressure can be characterized by six stages: wellbore storage effect and skin effect influence section,bilinear flow section,first-line flow section,matrix cross-flow section,second linear flow section and outer boundary influence section.These stages are affected by wellbore storage coefficient,skin coefficient,fracture half-length,fracture conductivity,inner zone radius,inner zone fluidity ratio and outer zone radius.In traditional production decline law is studied in this paper based on the analysis model,the seepage model of dense gas reservoir fracturing of horizontal composite area yield variation law of diminishing hyperbolic model and exponential decline model,harmonic decline model,diminishing HCZ model,Logistic regressive model,stretched exponential decline model and to simulate the diminishing SRVB model,The appropriate analysis model of production decline law of fractured horizontal Wells is optimized,and the relationship between production decline parameters and reservoir characteristic parameters and fracture parameters is determined.The calculation model of production decline parameters is further determined by multiple nonlinear regression method,which can calculate the production decline rate of fractured horizontal Wells in tight gas reservoirs.In this paper,the expression of productivity equation of fractured horizontal well in tight gas reservoir is deduced.The results show that the productivity equation of fractured horizontal well in tight gas reservoir is binomial.On this basis,analyzed the factor productivity equation and absolute open-flow capacity is affected by reservoir characteristic parameters and fracture parameters,and further used multivariate nonlinear regression method to get the binomial productivity equation coefficient and reservoir characteristic parameters and the relation between the fracture parameters,provide technical means for tight gas fracturing horizontal well productivity evaluation.Paper finally the target blocks of dense gas reservoir fracturing of horizontal well production dynamic data used in this paper,technology and methods are analyzed,the target block reservoir and fracture parameters,evaluation of target blocks fracturing of horizontal well production decline characteristics and characteristics of productivity change and verify the dynamic evaluation index in this paper,the production of practicability and reliability of the research methods.