角度不整合非均质薄油环油藏精细描述新方法

New method of fine description for unconformity heterogeneous thin oil rim reservoir

角度不整合接触倾斜薄油环油藏是一种特殊的油藏类型,如何精确刻画油藏特征,是制约该类油藏高效开发的重要因素。研究中创新地运用基于测井约束的地震反演技术,反演泥岩隔层,定量刻画泥岩隔夹层的空间展布和油藏内部非均质特征,精确刻画油藏空间特征。针对地层角度不整合薄油环油藏特点,提出"两步建模法":第1步,先根据地震解释隔层控制,结合地层对比结果约束,建立真实反映角度不整合接触倾斜地层特征的倾斜地质网格模型;第2步,采用网格转换技术,将建立好的倾斜网格模型转换为水平网格模型。这一建模方法大幅度地减少了角度不整合面附近三角网格数量,同时最大化反映了真实的复杂地质特征,提高了数值模拟的收敛性以及油藏开发动态历史拟合精度。

Unconformity heterogeneous thin oil rim reservoir is a special reservoir. How to describe its real space distribution characteristics is the key factor which could influence the development effectiveness. In this study, well logging constrained inversion method is used to invert barriers in the heavy layer. The 3D distribution characteristics of barriers and the reservoir heterogeneity are quantitatively analyzed. Due to the unconformity of the layers, ＂two-step modeling method＂ is used in the geology modeling. The first step is depended on barriers constrained to build one inclined grids model which really reflects the unconformity of layers. The second step is based on grids transformation technology to transform the inclined grids model to flat lying grids model. The flat lying grids model reduces the quantity of the triangular grids near the unconformity surface, which reflects the complex geologic characteristics and improves the convergence of sequent numerical simulation and the results of history match a lot.