【摘要】 地层孔隙度参数的准确求取是油气勘探中储层预测、储层描述、储量估算和油气藏综合研究的一项关键性技术,而运用常规方法对孔隙度进行计算存在精度不高、物理意义不明确等问题。为此,从岩石物理的基本理论和岩石物理测试数据出发,在合理的假设前提下,以Gassmann方程和Eshelby-Walsh方程为基础,推导和建立了利用高信噪比地震资料进行叠前弹性参数反演来计算地层岩石孔隙度的数学模型。选取实际资料的应用结果表明:①利用新模型可以提高碳酸盐岩储层孔隙度精确度约10%;②能够有效地计算预测地层孔隙度的纵横向展布,且符合地质、钻井认识规律;③利用地震资料叠前弹性参数反演获得的横波速度和体积密度剖面纵向分辨率较纵波速度剖面高,在此基础上开展的孔隙度计算能够提高孔隙度剖面的纵向分辨率。该数学模型提供的孔隙度数据为后期的钻井部署、储量估计、油气藏描述等研究提供了技术支撑。更多还原

【Abstract】 Accurate estimation of porosity is critical to reservoir prediction,reservoir characterization,reserves estimation,and comprehensive study of oil/gas reservoirs.However,conventional porosity estimation methods have the shortages of low accuracy and ambiguity of physical meanings.Based on the basic theories of petrophysics and geophysical test data and rational assumptions,a mathematical model was deduced and established by using the Gassmann and Eshelby-Walsh equations.This model can be used to calculate rock porosity through pre-stack elastic inversion of seismic data with high signal-to-noise ratios.Application of this new model to real data shows that it can improve the accuracy of carbonate reservoir porosity estimation by about 10%,and effectively predict the vertical and horizontal distribution of porosity.The vertical resolutions of S-wave velocity and bulk density profiles are higher than those of P-wave velocity profile,and the porosity calculation based on this can improve the vertical resolutions of porosity profile.The porosity data provided by this mathematical model are helpful for drilling planning,reserve estimation and reservoir characterization.更多还原