含浅层气砂土的赋存特征及其非饱和参数预测  

Occurrence characteristics and unsaturated parameters prediction of shallow gassy sand

作　　者：王勇[1] 孔令伟[1] 郭爱国[1] 田湖南[1] 

机构地区：[1]中国科学院武汉岩土力学研究所岩土力学与工程国家重点试验室,武汉430071

出　　处：《岩土力学》2011年第7期1945-1950,共6页Rock and Soil Mechanics

基　　金：国家自然科学基金资助项目(No.10872210);中国科学院知识创新工程重要方向项目(No.kzcx2-yw-150)

摘　　要：从地质成因角度分析了杭州地区浅层气藏的形成过程,探讨了储层土体的原始赋存分带特征,认为规模气藏中位于浅层气富集带内砂土的吸力变化范围不大,初始赋存含水率大致与其残余含水率接近,一般处于残余含水状态。基于VG模型描述的储气砂土-水特征曲线,提出了间接获取储层砂土非饱和参数的工程预测方法。对比试验结果表明:借助VGM模型、Parker模型和乘幂形式的强度公式,能够有效地预测含浅层气砂层的渗水系数、渗气系数和抗剪强度等非饱和参数,可满足地铁工程超前采取防治措施、消除浅层气地质灾害的需要。In view of geological origin, the formation of shallow gas in Hangzhou area was analyzed; and the original occurrence zonation characteristic of reservoir soil is investigated. It is shown that matric suction variation range of the gassy sand in enriched zone of scale gas reservoirs is not large, and its initial occurrence water content is close to its residual water content that means it is usually at the state of residual water content. Based on soil-water characteristic curve of the gassy sand described by Van Genuchten （VG） model, the indirectly engineering predictive methods to obtain unsaturated parameters of gassy soil are proposed. Results compared between the prediction and the experiment show that using Van Genuchten and Mualeum （VGM） model, Parker model and strength formula described by the power function, it is effective to predict the unsaturated parameters such as water and gas permeability coefficients, and shear strength of the reservoir soil, which can meet the need of preventive measures taken before metro construction to eliminate the shallow gas geological hazards.

关 键 词：浅层气 储气砂 赋存特征 地质灾害 

分 类 号：TU42[建筑科学—岩土工程]