基于数字露头的多尺度裂缝模型建立及其对地下裂缝预测指导  

Establishment of multi-scale fracture model based on digital outcrop and its guidance for subsurface fracture prediction

作　　者：高翔 冯建伟[1] 渠继航 杜赫 GAO Xiang;FENG Jianwei;QU Jihang;DU He(School of Geosciences,China University of Petroleum,Qingdao Shandong 266580,China)

机构地区：[1]中国石油大学(华东)地球科学与技术学院,山东青岛266580

出　　处：《地质科技通报》2024年第2期143-155,共13页Bulletin of Geological Science and Technology

基　　金：中国石油重大科技项目(ZD2019-183-006)。

摘　　要：塔里木盆地台盆区发育大面积的深层碳酸盐岩油气藏,构造裂缝是深层碳酸盐岩油气藏重要的储层渗流通道和储集空间,但受多种地质因素的影响其分布具有强烈的非均质性,目前无一套有效的技术方法解决储层多尺度裂缝定量化表征的难题。利用数字露头技术,建立露头区三维数字模型,并在此基础上开展露头裂缝识别及裂缝参数的定量描述。基于露头裂缝研究成果,对于不同尺度裂缝的发育特点采用不同的建模方法,针对大、中尺度裂缝,分别采用确定性建模方法和基于分维理论的优化融合建模方法;面对小尺度裂缝建模复杂的难题,利用多元信息融合方法融合断层走向模型、距断层距离模型以及地层构造曲率模型建立小尺度裂缝综合发育概率体,以裂缝综合发育概率体为约束,多元数据协同模拟构建小尺度裂缝网络模型。结果表明:在同一网格体系下,将多尺度裂缝模型及构造模型叠加获得露头原型地质模型。将露头原型地质模型研究成果应用于塔里木盆地跃满地区地下储层裂缝建模中,分尺度描述了裂缝产状、密度等主要建模参数,确定了裂缝发育主控因素,并结合井点裂缝分析成果,构建了储层多尺度裂缝网络模型,与单井裂缝解释、生产资料吻合度较好。实例研究表明露头原型地质模型研究成果可以为地下储层裂缝建模提供重要的研究思路和地质依据。[Objective] Large deep carbonate reservoirs have been developed in the Tarim Platform area.Structural fractures are important seepage paths and reservoir spaces for deep carbonate reservoirs.Due to the strong heterogeneity of reservoirs,which is influenced by multiple geological factors,there is no effective technical method to solve the problem of quantitatively characterizing multiscale fractures in reservoirs.[Methods] In this study,digital outcrop technology was used to establish a 3D digital model of the outcrop area,and on this basis,outcrop fracture identification and quantitative description of fracture parameters were carried out.Emphatically,based on the outcrop fracture results,different modelling methods have been adopted for the development of multiscale fractures.Large-scale fractures were modelled via the deterministic modelling method.Optimal fusion modelling methods based on fractal dimension theory were used for medium-scale fractures.Due to the complex problem of small-scale fracture modelling,three significant models were distinguished via the multisource information fusion method:the fault strike model,the distance from fault model and a stratigraphic curvature model.A comprehensive development probability body of small-scale fractures was established.Construction of a small-scale fracture model based on collaborative simulation of multiple data points was constrained by the comprehensive probability volume.Consequently,restricted by the established comprehensive probability volume,a small-scale fracture model was constructed based on collaborative simulations of multiple sets of data.Finally,under the same grid system,a prototype geological model of the outcrop was obtained by superimposing the multiscale fracture model and the structural model.[Results] The results of the outcrop prototype geological model were applied to fracture modelling of underground reservoirs in the Yueman area of the Tarim Basin.The primary modelling parameters,such as fracture occurrence and density,and the main co

关 键 词：数字露头 原型地质模型 深层碳酸盐岩储层 裂缝建模 分形分维 多尺度 地下裂缝 

分 类 号：P628[天文地球—地质矿产勘探]