碳酸盐岩油藏酸岩反应流动模拟研究进展

Status and Progress of Reactive Flow Simulations for Carbonate Reservoirs

酸岩反应流动模拟可用于指导油藏酸化施工,优选注入参数,从而以最小的成本最大程度地改善地层.国内外很多学者基于不同的方法建立了不同的模型对碳酸盐岩油藏酸岩反应流进行了研究,但这些模型尚缺乏科学的归纳与整理.以研究对象的空间尺度为依据,将现有的碳酸盐岩油藏酸岩反应流模型分为孔隙尺度模型、岩心尺度模型及井筒尺度模型,简要概括了每类模型的适用条件及其在应用中的局限性.结合本课题组在酸岩反应流模拟方面所做的工作,重点论述了岩心尺度模型的最新研究进展和发展趋势,给出了岩心尺度模型下一步的研究方向,主要包括:建立更接近地层实际的数学模型,如考虑酸化过程中存在的非达西流和地应力的影响;发展高效的数值算法,将模型的计算区域扩大到油藏尺度;将岩心尺度模型进行尺度升级,得到可以指导油藏酸化施工的优化参数.

Simulation results of the reactive flow of the acid in the rock generally are used to optimize the operation of reservoir acidization so that the optimal injection rate is determined to stimulate the formation effectively with minimum cost.Many models have been developed based on variety of methods to study the reactive flow in carbonate reservoir during acidizing.However,these models are still short of scientific classification and systematization.According to the spatial scale of the study objects,the existing models for reactive flow in carbonate rocks are classified into three types,namely pore-scale model,corescale model and wellbore-scale model in this study.The assumptions and limitations of each type are summarized.Based on the works we have done in the simulation of reactive flow in carbonate rock,the latest research progress and development trend of the core-scale model are presented in this paper.Besides,suggestions on the future studies on core-scale model are proposed,which include developing more accurate mathematical model,such as considering the effect of non-Darcy flow and the influence of stress,developing the efficient numerical algorithms to extend the computational domain to the whole reservoir,upscaling the core-scale model to obtain the optimal operating parameters during carbonate reservoir acidization.