浅层高渗砂岩油藏分级相控地质建模

Hierarchic Facies-Constrained Geological Modeling of Shallow High Permeability Sandy Reservoir

由于裂谷盆地浅层疏松砂岩储层非均质性强,渗透率级差变化范围巨大,常规相控建模无法表征储层内部非均质性,导致渗透率模拟结果与测井及试井解释难以匹配。为了解决这一难题,在沉积微相研究的基础上,利用流动分层指标(FZI)、孔隙喉道半径(R35)2个参数,将储层细分为4类流动单元,依据各流动单元的孔渗对应关系重新计算测井渗透率。采用分级相控建模的思路,首先建立沉积微相模型,在微相模型的控制下,建立流动单元模型。在此基础上,根据各流动单元的孔渗分布特征,建立各流动单元的孔隙度和渗透率场。该方法建立的三维地质模型,既精细刻画了储层内部非均质性,又能定量表征储层物性空间分布特征,保证渗透率模拟结果与测井及试井结果一致,为油藏数值模拟提供了准确的数据基础。

Due to the high heterogeneity of the shallow loosen reservoir sand in the rift basin,the range of permeability is so wide that the conventional facies constrained modeling cannot characterize the heterogeneity of inner sand bodies and may result in a great deviation away from DST results.This paper proposes an effective way to solve this problem.Based on the sedimentary microfacies results,the reservoir is subdivided into 4types of flow units by flow zone index（FZI）and pore throat（R35）,and the permeability is recalculated according to the porosity-permeability relationship of each flow unit.The flow unit model is constructed to characterize its spatial distribution quantitatively by hierarchic facies-constrained modeling,and porosity and permeability models are established under the control of flow unit model.The 3Dgeological model built by this method can delineate the heterogeneity of the reservoir sand and characterize reservoir property parameters distribution quantitatively.This provides an accurate data base for the reservoir numerical simulation.