岩石沉积学特征与岩石弹性参数的关系  

Relationship between rock sedimentary feature and its elastic parameters

作　　者：贺芙邦[1] 游俊 高凤英 邵龙义[1] 

机构地区：[1]中国矿业大学(北京)地球科学与测绘工程学院,北京100083 [2]北京阳光杰科科技股份有限公司,北京100192

出　　处：《油气地质与采收率》2016年第1期61-67,共7页Petroleum Geology and Recovery Efficiency

摘　　要：岩石物理基础研究结果表明,岩石的弹性特征是由岩石内在的矿物成分及含量、孔隙和孔隙流体等物理参数所决定的,而这些物理参数又受岩石的沉积环境、沉积过程和后续成岩作用等因素控制。研究岩石的物理参数与其物性和弹性参数之间的关系,对利用地震弹性参数预测油气储层具有一定的指导意义。通过岩石物理分析技术,系统地分析某扇三角洲成因砂砾岩储层的岩性和孔隙流体等物理参数对岩石密度以及速度和模量等弹性参数的影响,结果表明,纵横波速度比、横波波阻抗、剪切模量和剪切模量与密度乘积等参数对砂砾岩与泥质岩比较敏感,可用于砂砾岩的分布预测;纵横波速度比、拉梅常数与密度乘积能够较好地区分含油和含水砂砾岩,可用于油层预测。进一步研究发现,当地层沉积序列由多沉积旋回细分至单个沉积旋回时,岩石孔隙度与纵波速度和纵波波阻抗的相关性呈现逐步变好的趋势,但它们之间并非简单的线性关系,且受泥质含量影响较明显。Fundamental research on rock physics indicates that rock elastic features are essentially determined by its physical properties like mineral contents,texture,porosity,pore fluid and so on. However,rock physical properties are closely related to and affected by its sedimentary environment,process and consequent diagenesis history. Study on the influences of rock sedimentary features on its elastic parameters will be beneficial to reservoir prediction using seismic elastic parameters.Taking a fan-delta sandy conglomerate reservoir,the impacts of the rock physical parameters like lithology and pore fluid on its elastic parameters like density,velocity and modulus were analyzed systematically through rock physics analysis technique. The results show that velocity ratio of compressional and shear wave,shear wave impedance,shear modulus and μρ(the product of shear modulus and density)are sensitive to sandy conglomerate and mudstone,which can be used to predict the distribution of sandy conglomerate. The velocity ratio of compressional and shear wave and λρ(the product of Lame constant and the density)can be used to discriminate oil layer from water layer and to predict oil layer. Further research demonstrates that the correlations of velocity and impedance with rock porosity are becoming better when the multiple sedimentary cycles of stratigraphic sedimentary sequences are divided finely into single cycle. But their relationships are not linear and affected apparently by shale content.

关 键 词：沉积学特征 岩石物理分析 岩石弹性参数 储层预测 砂砾岩 沉积旋回 

分 类 号：P631.44[天文地球—地质矿产勘探]