基于不同尺度的储层裂缝建模方法对比

Comparison of reservoir fracture modelling methods based on fracture scales

裂缝是影响低孔低渗透储层产能的关键因素之一,相应的裂缝建模方法是国内外学者关注的重要领域.本文对近年来国内外主要的裂缝建模方法进行了分析,可基于裂缝尺度特征分为3类:叠前地震属性相比叠后属性包含地质信息更丰富,并可预测大尺度裂缝的发育方向、强度和密度;基于微震事件的DFN建模方法在保证更多的中小尺度裂缝被检测到的情况下,模型更加贴近实际油气生产;计算机断层扫描技术可以定量表征微米级微小尺度裂缝,获得更为精确的小尺度裂缝信息.在实际储层中,其裂缝特征往往具有多尺度性,单一的裂缝建模方法不够全面.基于裂缝特征详细划分裂缝尺度,整合不同尺度裂缝信息进行建模成为了新的研究方向之一.多尺度裂缝表征为低孔低渗透储层裂缝的三维地质建模提供了重要的思路.

Fracture is one of the key factors affecting the productivity of low-porosity and low-permeability reservoirs,and fracture modelling is an important area of interest for scholars at home and abroad.In this article,the main fracture modeling methods are analyzed.These modeling methods can be divided into three categories based on fracture scale characteristics.Frist,pre-stack seismic attributes contain richer geological information than post-stack attributes and can predict the development direction,intensity and density of large-scale fractures.Second,DFN(Discrete Fracture Network)modelling methods using microseismic events information can ensure more small-and medium-scale fractures are detected,and this kind of modeling methods is more fitting for the actual oil and gas production.At last,the computed tomography technique can quantitatively characterize micro-scale fractures at the micron level and obtain more accurate information on small-scale fractures.For the actual reservoir,the fracture characteristics are often multi-scale,and the single fracture modeling method cannot meet the requirements of actual accurate modeling.It has become one of the new research directions to divide fracture scale in detail based on fracture characteristics and integrate fracture information of different scales for modeling.Therefore,multi-scale fracture characteristics should be used for 3D geological modeling of fractures in low porosity and low permeability reservoirs.