多尺度裂缝建模方法及其应用——以塔里木盆地克深2气田致密砂岩储层为例  

Multi-scale fracture modeling method and its application:A case study of tight sandstone reservoir in Keshen 2 Gas Field, Tarim Basin

作　　者：罗骞 唐海发[2] 刘群明[2] 尹艳树[1] 王立鑫 尚浩杰 LUO Qian;TANG Haifa;LIU Qunming;YIN Yanshu;WANG Lixin;SHANG Haojie(School of Earth Sciences,Yangtze University,Wuhan 430100,China;Research Institute of Petroleum Exploration and Development,PetroChina,Beijing 100083,China)

机构地区：[1]长江大学地球科学学院,湖北武汉430100 [2]中国石油勘探开发研究院,北京100083

出　　处：《天然气地球科学》2024年第6期1000-1013,共14页Natural Gas Geoscience

基　　金：国家自然科学基金项目“利用任意二维沉积相剖面重构三维地质模型新方法”(编号:42372137)资助。

摘　　要：塔里木盆地库车坳陷下白垩统巴什基奇克组克深2气田致密砂岩储层裂缝发育情况复杂,极大影响了气藏开发,因此亟需准确表征裂缝特征并建立其三维地质模型,服务气藏开发策略和高效调整。基于岩心、测井和地震资料,开展了裂缝识别和表征研究,完成了多尺度裂缝的划分,研发了多尺度裂缝建模新方法,实现了多尺度裂缝精细模型建立。结果表明:①研究区发育3种级别裂缝,其中岩心、成像测井识别了中尺度、小尺度裂缝,延伸方向为EW、NS向,地震上识别了大尺度裂缝,延伸方向为EW向。②基于裂缝延伸距离和开度,研究区裂缝可划分为大尺度、中尺度和小尺度裂缝。其中大尺度裂缝延展长度为数十米至百米级,裂缝开度为1~100 mm,穿单层;中尺度裂缝延展长度为米级至数十米级,裂缝开度为0.5~1 mm,砂层内发育;小尺度裂缝延展长度为厘米级至米级,裂缝开度为0.001~0.5 mm,砂层内发育。③不同尺度裂缝发育密度不同,地层曲率和断层距离对裂缝发育强度有影响,建立了融合地层曲率和断层距离的裂缝发育强度属性体约束不同尺度裂缝强度模型。④研发了改进的DFN方法,将共轭剪切缝等裂缝组合作为整体刻画与投掷,将弯曲裂缝用多段直线表征,将不同尺度裂缝视为不同沉积单元,实现了研究区多尺度裂缝模型建立。抽稀验证表明,模型平均误差值为11.4%,而传统软件DFN方法平均误差值为24.6%,模型准确度更高。The development of tight sandstone fractures in the Lower Cretaceous Bashijiqike Formation Keshen 2 Gas Field in Kuqa Depression,Tarim Basin is complicated,which greatly affects the development of gas res⁃ervoirs.Therefore,it is urgent to accurately characterize the fracture characteristics and establish a three-dimen⁃sional geological model to serve the development strategy and efficient adjustment of gas reservoirs.Based on core,logging and seismic data,the study carried out fracture identification and characterization research,com⁃pleted the division of multi-scale fractures,developed a new method for multi-scale fracture modeling,and real⁃ized the establishment of a detailed multi-scale fracture model.The results show that:(1)There are three lev⁃els of fractures in the study area.The medium and small scale fractures are identified by core and imaging log⁃ging,and the extension direction is EW and NS.The large scale fracture is identified by seismic,and the exten⁃sion direction is EW.(2)Based on the fault extension distance and opening,the fractures in the study area can be divided into large-scale fractures,medium-scale fractures and small-scale fractures.The large-scale fracture extends for tens of meters to hundreds of meters,and the opening is 1−100 mm,and it penetrates single layer.The medium-scale fracture extends for meters to tens of meters,and the opening is 0.5−1 mm,and it develops in sand layer.The small-scale fracture extends for centimeters to meters,and the opening is 0.001−0.5 mm,and it develops in sand layer.(3)Different scales of fractures have different development densities,and the for⁃mation curvature and fault distance have an impact on the fracture development strength.A fracture develop⁃ment strength attribute body integrated with the formation curvature and fault distance is established to constrain the strength of fractures at different scales.(4)An improved DFN method is developed,which takes the frac⁃ture combinations such as conjugate shear fractures as a w

关 键 词：克深2气田 致密砂岩储层 多尺度裂缝 表征方法 DFN方法 

分 类 号：TE34[石油与天然气工程—油气田开发工程]