岩屑回注的数值模拟方法  

A numerical method for simulating cuttings reinjection

作　　者：王笑雨[1,2] 张可霓[1,2] 郭朝斌[3] 陈开军 李毅[1,2] 

机构地区：[1]北京师范大学水科学研究院,北京100875 [2]北京师范大学地下水污染控制与修复教育部工程研究中心,北京100875 [3]同济大学机械与能源工程学院,上海200092 [4]杰瑞能源服务有限公司,山东烟台264003

出　　处：《水文地质工程地质》2015年第6期137-144,共8页Hydrogeology & Engineering Geology

基　　金：能源科技发展项目专项(NY20111102-1)

摘　　要：岩屑回注技术经济环保,但其发展时间较短且浆液流变学性质复杂。为探究浆液与地下水流动系统的相互作用,开发模拟器,建立孔隙/裂隙介质中宾汉流体型浆液的岩屑回注三维全隐式积分有限差分模型,通过流体状态方程编程实现其运移模拟。模拟器综合考虑了浆液的非牛顿流动过程,浆液与水的混合流动过程,浆液与水混合流体的沉淀与稀释过程,沉淀对地层孔隙度、渗透率的影响。从而实现对三维非结构网格、非均质孔隙/裂隙介质中的浆液运移情况的数值模拟,在不同岩性、浆液性质、注入条件下,分析浆液运移规律、地层压力分布、盖层封闭性,预测回注储量,确定最优回注方案,评估潜在风险。通过理想模型展示模拟器功能,发现浆液在停注期产生大量沉淀堵塞地层,因而间歇回注会使得地层压力激增而更快达到破裂压力。实际工程中应特别注意短周期间歇注入对地层的损害。Cuttings reinjection is an economical and environmental friendly technology. In order to examine the interaction of slurry and subsurface system,this paper develops a three-dimensional,fully implicit,integral finite difference simulator for the process of cuttings reinjection in porous / fractured media. The methodology takes into consideration the non-Newtonian fluid properties of the suspension slurry,the mix flow of slurry and groundwater,precipitation – dissolution of the mix flow and the effect of precipitation on porosity and permeability. This simulator accordingly is used to analyze the slurry transport pattern,pressure distribution,sealing ability of cap rock and predicts formation capacity,and further helps determine the optimal injection scheme with a three-dimensional irregular mesh gird in the heterogeneous porous / fracture system. It is helpful in the potential risk in practical project. As shown in a numerical example,precipitation mainly occurs in the shut-in period,which leads to a clog in the formation,and hence a rapid increase in the formation pressure.There is a risk of causing a breakdown of the formation in performing an intermittent injection,so special attention should be paid to short period intermittent injection in practice.

关 键 词：岩屑回注 浆液 宾汉流体 数值模拟 间歇回注 

分 类 号：P642[天文地球—工程地质学] X141[天文地球—地质矿产勘探]