基于岩心岩脉弯曲度的泥岩压实率研究  

Discussion about mudstone compaction rate with curvature of sandstone dikes in cores

作　　者：杨冠群 钟建华 郝兵 孙宁亮 

机构地区：[1]中国石油大学地球科学与技术学院,山东青岛266580

出　　处：《能源与环保》2017年第7期69-76,共8页CHINA ENERGY AND ENVIRONMENTAL PROTECTION

基　　金：国家自然科学基金(41572088)

摘　　要：针对泥岩压实作用国内缺少定量表征方法的问题,通过归纳和总结前人研究成果,结合在研究中遇到的实际情况,剖析了地震成因的液化砂岩脉的成因机制,认为其形成过程包括砂岩液化形成超压、泥岩破裂、砂岩流化与充注3个阶段,液化砂岩脉与其侵入泥岩的后期成岩过程是同步的,机械压实作用是砂岩脉弯曲变形的主导因素。基于岩土塑性力学理论,在国内首次提出了运用岩心砂岩脉弯曲度定量表征泥岩压实率的新方法。样品数据分析结果表明,泥岩压实率与泥岩体积压缩率C相关性高达0.91;同时根据泥岩压实率分布规律将泥岩压实作用划分弱压实(C<1.66)、中等压实(1.66<C<3.55)、强压实(C>3.55)3种类型,泥岩越厚,压实程度越高。该文还简要探讨了新方法的可行性,以期对泥岩压实作用理论研究有所裨益。Mudstone compaction is very important for oil and gas exploration and development. At present,there is no relevant quantitative research method in China. The research status and development trend of mudstone compaction has been summarized. Combined with the actual situation,we have analyzed the genetic mechanism of liquefaction sandstone dikes caused by the earthquake. There are three phases of sandstone dikes deployment： liquefied sandstone forms overpressure,mudstone fracturing,then sandstone flowing and filling.The metharmosis of the sandstone dike is synchronous with the mudstone. The leading factor causing the sandstone dikes bending deformation is mechanical compaction. Based on the theory of geotechnical plastic mechanics,this paper presents a new method for quantitative study of mudstone compaction. The curvature of sandstone dikes is used to quantitively characterize the mudstone compaction rate. The result of experimental data analysis shows that the correlation between mudstone compaction rate and volume compressibility is up to 0. 91. The mudstone compaction can be divided into three types with different mudstone compaction rates： weak compaction（〈1. 66）,medium compaction（ 1. 66 ~ 3. 55） and strong compaction（ 〉3. 55）. As mudstone thickness increases,the degree of mudstone compaction strengthens. The article also briefly discusses the feasibility of the new method. It will be conducive to developing the theoretical study on mudstone compaction.

关 键 词：泥岩压实率 砂岩脉 弯曲度 成因机制 定量表征 

分 类 号：P618.13[天文地球—矿床学]