低渗储层岩石物理建模新方法及其在东海Z气田中的应用

    A new method of rock physics modeling and its application in low permeability reservoirs of Z Gasfield, East Sea Basin

    • 摘要: 低渗储层孔隙结构复杂,非均质性强,不同类型低渗储层之间也常存在较大物性变化,难以采用统一的岩石物理模型表征储层参数与弹性参数之间的关系。针对上述难题,提出了低渗储层分层岩石物理建模方法:针对中低孔-中低渗储层采用基于DEM理论的流体均匀饱和模型;针对特低孔、特低渗储层采用基于KT理论的流体非均匀饱和模型。基于分层岩石物理建模预测的纵、横波速度与测井真实速度吻合较好,验证了该方法的可靠性。在建立准确岩石物理模型的基础上,进一步分析了弹性参数受泥质含量、孔隙度、孔隙形状等因素影响的变化规律,从而指导低渗储层的岩性及“甜点”预测。

       

      Abstract: Low-permeability reservoirs have complex pore structure characteristics for which conventional petrophysical modeling methods are not suitable for detection. In addition, physical properties among different layers of low-permeability reservoirs vary considerably, so it is difficult to use unified petrophysical model to characterize the relationship between reservoir parameters and elastic parameters. We proposed a new technical approach to stratified rock physics modeling of low permeability reservoirs: for medium-low porosity and medium-low permeability reservoirs, the fluid uniform saturation model based on DEM theory was adopted; for extra-low porosity and extra-low permeability reservoirs, the fluid non-uniform saturation model based on KT theory was adopted. The predicted P-wave and S-wave velocities based on stratified rock physical modeling were in good agreement with the real logging data, which verified the reliability of the method. Based on the accurate petrophysical models, the laws of elastic parameters variations with shale content, porosity, and pore shape were further analyzed, to guide the prediction of lithology and "sweet spot" in low permeability reservoir.

       

    /

    返回文章
    返回