Dynamic Numerical Simulation Of Fractured Horizontal Well Production

Horizontal well fracturing has been an important technich for development of low permeability reservoir. Productivity predicting of horizontal well is used to instruct fracturing designs before practicing in oil field, how to predict productivity of fractured horizontal well is a important research field with increasing the amount of fractured horizontal well. Traditional predicting ways are using analytic formula model and numerical simulation model,but numerical simulation model is not perfect. Based on the technology demand of productivity of hydraulically fractured horizontal well, this paper produce a three-dimensional and two phase numerical simulation model to predict productivity of hydraulically fractured horizontal well,and accomplished research contents as followed:(1) According to reservoir-fracture grid system and IMPES differential method, this paper established a three-dimensional and two phase formula numerical simulation model to predict productivity of hydraulically fractured horizontal well.In the model,reservoir and fractures are in same fluid flow system,the fracture with block width equal to fracture width and small grid spacing was introduced close to the fracture face near the well are modeled,form a huge seven diagonal linear equation group after difference, Line Successive Over Relaxation(LSOR) is used to calculate the equation.In this paper,several conditions are considered in simulation ,such as variation of fracture conductivity with time and effect caused by fluid flowed rapidly in farctures.(2) According to established model , a software of predicting productivity of hydraulically fractured horizontal well is developed by VisualBasic 6.0 language.(3) According to developed programme, several factors are calculated and analysed, such as fracture conductivity, fracture length, fracture space, fracture number, reservoir permeability, fracture conductivity and length with different resevoir permeability,well flow pressure,water saturation,non-equality fracture length. In addition , two other factors that hane not appeared in the literature are analysed: relative permeability curve and boundry conditions,results show that these factors have improtant impact to productivity of hydraulically fractured horizontal well.(4) According to comparison of production performance of fractured horizontal well and fractured vertical well, it is proved that model of productivity predicting of horizontal well by numerical simulation with casing perforated completion is more resonable, in addition ,reaearch show perforating production has certain impact to horizontal well's production.(5) A model to calculate Net Present Value of fracture number was established, it and programme of predicting productivity of hydraulically fractured horizontal well was used toevaluate different fracture number's NPV and the optimum fracture number of hydraulically fractured horizontal well.This paper studied in detailed for the aboved aspects contents, and some of aspects content is novel and very difficult. Based on the above systematical study, this paper preliminary established a set of relatively whole fundamental theory models for productivity predicting of hydraulical fractured horizontal well, the corresponding software for productivity predicting of hydraulically fractured horizontal well is programmed by making use of the programming language of Visual Basic 6.0 ,and it can be used to guide the hydraulically fractured horizontal well.