Well Testing Analysis For Fractured Well In A Low-permeability

The development of low permeability oil-gas reservoirs is always a difficulty in petroleum industry. Fractured technique is an effective measure for developing the low permeability reservoir. After fractured, it can form some fractures that are vertical fractures and horizontal fractures.. In order to analyze and estimate fractured effect, we can obtain some parameters about well through the well testing. There are some defects in the existing well test models for low permeability reservoir, for instance, Vertical Fracture Bilinear Flows models does not consider the non-darcy flow formation, and the external boundaries trilinear flow model just consider the outer boudaryis infinite; Horizontal Fracture model is seldom studied, which made the interpretation result much different from the actual one.The mechanisms of fluid flowing through porous media in reservoir and fractures are further studied in this paper. Bilinear flow model of finite conductivity vertical fracture by low-velocity non-Darcy’s law in homogenous reservoir has been established, effects of wellbore storage and skin are included, and then drawing the pressure and pressure derivative typical curves. Besides that, for low permeability, Trilinear flow model which considered the outer boundary is infinite is line and channel also has been established, effects of wellbore storage and skin are included, and then drawing the pressure and pressure derivative. Besides that, this paper also studies horizontal fracture well test model in the homogeneous reservoir, which considered the external boundaries are constant and pressure. Effects of wellbore storage and skin are included, and then typical curves are plotted. It is found that the vertical position of horizontal fracture in the reservoir should be taken into consideration.Finally well test models are added into Swift well test analysis software in this paper. Many well datas from YanChang Oilfeild are interpreted, the result shows that those explanation results are tally with the actual situations. This well test models can make better use of well test data of low permeability reservoir, and they not only improve the accuracy of well testing interpretation results, but also provide reliable reference for dynamic analysis.