基于粒度控制的复杂储层渗透性建模方法

Method of Permeability Model Establishment Based on the Complex Reservoir Controlled by Particle-Size

岩石颗粒大小反映了沉积岩结构的主要特征,是岩石岩性的主要评价指标,同时也是影响沉积物渗透性的主要因素。沉积环境在纵向上表现出来的差异性,使得粒序控制下的地层渗透性在纵向上也表现出非均质性。为了精细地描述由于粒度大小造成的渗透率的非均质性,本文首先结合岩心粒度分析资料,分析了研究区粒度大小对物性影响的规律,利用自然伽马、中子、密度、声波曲线,通过测井地质分析提取敏感参数,建立了粒度计算模型;然后以粒度为指标,建立了不同粒度大小条件下的渗透率计算模型。通过现场资料的处理及其与岩心资料的对比,认为这种渗透率建模方法能够较好地反映沉积物粒度对岩石渗透性的控制作用,能够更加精确地描述复杂岩性地层渗透率的非均质性特征,从而可为地质开发研究提供更为准确的渗透率剖面。

Particle-size is one of the main feature of sedimentary rock structures, the main indicators to evaluate the rock lithology, and also the main controiling factors on the sediment＇s permeability. As the sedimentary environment manifests differences in vertical, the permeability controlled by particlesize also shows heterogeneity in vertical. In order to describe the heterogeneity of the permeability caused by particle-size precisely, the authors utilize GR, CNL, DEN, and DT curves, combine with the particle-size analysis data of cores, abstract several parameters which are sensitive to particle-size, and set up a model to calculate the particle-size. Then, the permeability model under the conditions of different particle sizes is established. Through field data processing and contrast of core data, this model has been proved to be feasible＇ in reflecting the control mechanism of sediment particle-size to the permeability, and in describing the heterogeneity of the permeability in reservoirs with complex lithology more precisely. A more accurate permeability profile is thereby provided for geological research and development.