摘要
针对润湿黏土甲烷吸附规律认识不足的问题,利用页岩扫描电镜图像将气体储集空间按不同尺寸和几何形状划分为等径圆形孔隙、扁平状椭圆孔隙及条带状裂缝3类,并依据干燥黏土气-固界面的Langmuir吸附式、润湿黏土气-液界面的Gibbs吸附式,建立考虑水敏性的页岩黏土气-液-固三相界面耦合甲烷吸附模型,结合考虑吸附相体积的游离气含量计算式,推导不同含水饱和度下页岩黏土的含气量预测方程。结果表明,与涪陵焦石坝地区页岩岩心现场解析数据相比,润湿黏土多相耦合模型的计算结果精度较高。研究结果对不同含水率下页岩黏土甲烷静态资源量的评估具有重要的指导意义。
Shale scanning electron microscopy images were used to classify the gas reservoir space according to the sizes and geometries to explore the methane adsorption pattern in wetted clay.The reservoir space was classified into three categories,including equal-diameter circular pore,flat elliptical pore and stripped crack.A gas-liquid-solid 3-phase interface coupling methane adsorption model for the shale clay considering water sensitivity was established based on the Langmuir adsorption equation for the gas-solid interface of dry clay and the Gibbs adsorption equation for the gas-liquid interface of wet clay.The gas content prediction equation for the shale clay under different water saturations was derived according to the free gas content equation considering adsorbed phase volume.Result indicates that this multi-phase coupling methane adsorption model shows a favorable prediction through the comparison with field desorption data of shale core samples from Jiaoshiba in Fuling.This research could provide certain guidance for the static resource evaluation of shale clay methane under different water saturations.
作者
黄瑞
陈军斌
王佳部
姚欢迎
Huang Rui;Chen Junbin;Wang Jiabu;Yao Huanying(Xi′an Shiyou University,Xi′an,Shaanxi 710065,China;Shaanxi Key Laboratory of Well Stability and Fluid&Rock Mechanics in Oil and Gas Reservoirs,Xi′an,Shaanxi 710065,China)
出处
《特种油气藏》
CAS
CSCD
北大核心
2019年第5期92-99,共8页
Special Oil & Gas Reservoirs
基金
国家自然科学基金“基于细-宏观力学的页岩储层脆性破坏机理研究”(51674197)
“陆相页岩井周天然裂隙力学活动性评价方法基础研究”(51874239)
