基于DFN离散裂缝网络模型的裂缝性储层建模方法

针对目前裂缝性储层建模方法存在的问题, 探讨DFN离散裂缝网络模型的裂缝性储层建模的思路和方法, 提出分大尺度和中小尺度两种裂缝级别建立DFN离散裂缝模型。首先, 按照确定性建模方法, 以三维地震资料建立大尺度裂缝的空间分布模型。然后, 以岩芯观测和成像测井解释的裂缝密度、长度、倾角、方位等统计信息为基础, 在地震裂缝预测的属性体约束下, 建立全区裂缝密度分布模型, 并以该数据体为约束, 利用随机建模方法, 建立中小尺度的裂缝网络模型, 实现井间裂缝密度的约束。最后, 通过整合大尺度和中小尺度的DFN模型, 建立Z地区综合离散裂缝网络模型及其裂缝孔隙度、渗透率等属性模型。该模型反映了储层裂缝的三维空间分布特征, 为该区油藏数值模拟提供了地质基础。

Fractured Reservoir Modeling Method Based on Discrete Fracture Network Model

According to the problem of the fractured reservoir modeling, an approach of Discrete Fracture Network (DFN) model of fractured reservoir is discussed. The proposal of the DFN fracture model is built by dividing into the large and small-mid scales of fracture. Firstly, with the deterministic modeling method, the large scale of fracture model is built with the 3D seismic data. Secondly, based on the well fracture density, length, dip and azimuth, which are calculated from well core observation and image log calibrations, using the prediction of fracture from the seismic attribute volume as constraints, the whole area fracture density distribution model is built. And then, taking the fracture density model as constraints and using the stochastic modeling method, the small-mid scale of fracture model is generated from fracture density model. The constraint for inter well fracture density is realized. Finally, integrated with the large and small-mid scales of the DFN models, the comprehensive discrete fracture network fracture model and the models of fracture porosity and permeability are established in Z Area. This model reflects the characteristics of reservoir fracture in three-dimensional space, which provides the foundation of geological for the numerical reservoir simulation in Z Area.