雷州半岛南部玄武岩岩石物理特征

基于雷州半岛南部51件玄武岩岩心样品在饱和气、饱和水状态下的纵、横波波速和弹性模量等参数的测试结果，研究了孔隙度、孔隙类型、岩相和流体对岩石弹性力学参数的影响，分析了用于识别玄武岩岩性、流体的岩石物理参数的敏感性。研究结果表明：玄武岩中纵波波速与横波波速、密度与纵波波速具有较好的线性关系，杨氏模量与密度呈幂函数关系。孔隙度是影响岩石波速的主要因素，孔隙类型对岩石波速的影响不可忽视。岩石密度是区分玄武岩岩石亚相最敏感的岩石物理参数，利用密度与杨氏模量的交会关系可识别玄武岩的溢流相上部亚相、中部亚相和下部亚相。利用泊松比与纵波阻抗交会图、拉梅系数和剪切模量之比与纵波阻抗交会图可以区分玄武岩中的气层与水层。

Petrophysical characteristics of basalt in the southern Leizhou peninsula

Based on the test results of the primary wave (P-wave) velocities, shear wave (S-wave) velocities and elastic moduli of 51 core samples of basalt under saturated gas and water condition in the southern Leizhou peninsula, this paper studies the influence of porosity, pore types, lithofacies and fluids on the elastic mechanical parameters of rock and analyzes the sensitivity of petrophysical parameters for identifying the lithology and fluid content of basalt. The results show that in basalt, there are good linear relationships between P-wave velocity and S-wave velocity, as well as between density and P-wave velocity. There is a power function relationship between Young's modulus and density. Porosity is the main factor affecting the wave velocity in rock, and the effect of pore type on the wave velocity of rock cannot be ignored. Rock density is the most sensitive petrophysical parameter for distinguishing the sub-lithofacies of basalt. The cross plot of density versus Young's modulus can be used to identify the upper, middle and lower sub-lithofacies of flood basalt. The cross plots of the Poisson's ratio versus P-wave impedance and the ratio of Lame coefficient to shear modulus versus P-wave impedance can be used to distinguish gas-bearing zone and water-bearing zone in basalt.