中南大学学报（自然科学版）2016，Vol.47Issue(12)：4140-4146,7.DOI:10.11817/j.issn.1672-7207.2016.12.024
页岩气藏多级压裂水平井压力动态分析
Pressure dynamic analysis of multistage fractured horizontal well in shale gas reservoirs
摘要
Abstract
The multi-fractured horizontal well(MFHW) unstructured grids were generated by using the Voronoi grid technology and the transport mathematical model which considers adsorption/desorption, diffusion and Darcy flow in shale gas reservoirs was established by introducing Dusty Gas Model. Furthermore, the numerical mathematical model for MFHW in shale gas reservoirs was derived based on control volume finite element method and fully implicit method, and the typical curves of transient pressure dynamic analysis for MFHW were drawn by computer programming. The results show that typical curves of pressure dynamic analysis for MFHW in shale gas reservoirs can be divided into seven flow stages which include wellbore storage, transient flow, fracture linear flow, early time radial flow around, compound linear flow, system radial flow and boundary flow. When the adsorption/desorption is stronger, the position of typical curves is lower, meanwhile there is a characteristic dip in the pressure derivative during transient flow stage because of the biggest pressure drop and the largest gas supply amount of desorbed gas near the well bottom. However, the dip of the pressure derivative may be masked off due to influence of desorption strength. And the flow capacity in ultra-low permeability shale gas reservoir can be improved by diffusion coefficient, and when the diffusion coefficient reaches a certain value, the position of the curves’ flow stages which is influenced goes lower. Besides, the influences of permeability, fracture number, half length of fracture and fracture space on shale gas MFHW well pressure danamic behaviors are consistent with that on conventional gas reservoirs.关键词
页岩气/压裂水平井/PEBI网格/吸附解吸/不稳定压力Key words
shale gas/multi-fractured horizontal well/PEBI grid/adsorption/desorption/transient pressure分类
能源科技引用本文复制引用
魏明强,段永刚,方全堂,雷小华,唐澜..页岩气藏多级压裂水平井压力动态分析[J].中南大学学报（自然科学版）,2016,47(12):4140-4146,7.基金项目
国家重点基础研究发展规划(973计划)项目(2013CB228005)(Project (2013CB228005) supported by the National Basic Research Development Program of China) （973计划）
