Abstract: The bottom water will soon break through all in a sudden in large-fractured gas wells. It is quite necessary to study the flow law of gas and water in reservoir condition through numeri cal simulation so as to enhance gas recovery. Unfortunately,conventional numerical calculating method can not solve the water coning problem of large-fractured gas wells. Therefore, on
the basis of tensor transformation and finite volume method, we developed a numerical calculating method to solve the 3D water coning problem of large-fractured gas wells. According to our research, we came to a conclusion that the main permeability direction of large fracture points to the tangent of large fracture curve. We presented the discretization equations of 3D water
coning of large-fractured gas wells in this work. The case study results show that the method presented in this paper is more accurate in modelling the process of bottom water breakthrough than conventional method.

Key words: finite volume method, large fracture, bottom water coning, numerical simulation, tensor transformation