论文部分内容阅读
ODP1144站是南海唯一钻揭深海沉积牵引体的站位,其完整的岩芯和测井资料为开展该沉积牵引体的岩石物理模型研究提供了良好的基础。此项研究对于理解南海深海沉积物中岩性参数与弹性参数间的关系具有重要意义,并可为根据反射地震资料开展定量岩性参数预测提供依据。对现有的深海沉积物岩石物理模型包括Wood悬浮模型、等球体颗粒接触模型、Sun速度—孔隙度关系模型进行了综述。根据岩芯分析资料将1144站深海沉积物的矿物组分简化为粘土矿物、碳酸盐、陆源碎屑和硅质生物4类;其中后3种组分的弹性模量及密度值分别由其代表矿物——方解石、石英及蛋白石的理论值代替,粘土矿物组分的等效弹性模量和等效密度则分别由Voigt-Reuss-Hill平均和体积平均计算得出。将3种岩石物理模型应用于1144站,计算得出深海沉积物的纵波速度并将其与声波测井纵波速度进行比较。结果表明,Sun模型计算结果与实测结果的吻合最好,误差最小;Wood模型所得结果在浅层与实测结果较吻合,在深层与实测结果出现偏差,误差较小;而等球体颗粒接触模型计算结果整体偏高,误差较大。
ODP station 1144 is the only station in South China Sea that drills deep-sea sedimentary traction bodies. Its complete core and well logging data provide a good foundation for the study of petrophysical models of this deposit. This study is of great significance to understand the relationship between lithology parameters and elastic parameters in deep-sea sediments of the South China Sea and provide a basis for quantitative lithology parameter prediction based on reflected seismic data. The current petrophysical models of deep-sea sediments including Wood suspended model, iso-spherical particle contact model and Sun velocity-porosity relationship model are reviewed. Based on the core analysis data, the mineral composition of deep sea sediments at station 1144 is simplified into four categories: clay minerals, carbonate, terrigenous debris and siliceous organisms. The elastic modulus and density of the latter three components are respectively Representing the theoretical values of minerals - calcite, quartz and opal, the equivalent elastic modulus and equivalent density of the clay mineral components are respectively calculated from Voigt-Reuss-Hill average and volume average. Three kinds of petrophysical models were applied to 1144 stations to calculate the P-wave velocity of deep-sea sediments and to compare them with P-wave velocity. The results show that the Sun model calculation results are in good agreement with the measured ones and the errors are the least. The results obtained by Wood model are in agreement with the measured ones at the shallow layer and the deviations at the deep layer and the measured ones with small errors. However, The overall result is high and the error is large.