具有大裂缝的气井水锥问题的数值模拟

当具有大裂缝的底水气田的气井生产时,经常发生底水突然通过大裂缝串入井孔而影响天然气生产。显然,借助数值模拟方法以了解地下气、水流的动态变化对于提高采收率甚为重要。但是对有大裂缝的气田,普通数值方法结果无效,必须另辟途径。通过讨论大裂缝三维水锥问题的数值模拟,认定大裂缝的主渗透率方向在大裂缝曲线切向上,借助张量变换理论和有限体积法,导出了描述有大裂缝的三维气井水锥的离散方程。实算表明了这种方法比通常方法更能反映气井水窜真实过程。

NUMERICAL SIMULATION STUDY ONWATER CONING OF LARGE-FRACTURED GAS WELL WITH FINITE VOLUME METHOD

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, onthe 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 waterconing 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.