基于无人机倾斜摄影的三维露头地质建模:以山西吕梁市坪头乡剖面为例*

针对野外露头地质知识库数据获取方法存在的不足,利用无人机倾斜摄影的敏捷、全局性视角及定量化程度高的特点,对山西吕梁市坪头乡剖面野外露头数据进行了采集、处理与地质解释,建立了野外露头区地质知识库,并以此为基础建立了典型区块野外露头内部三维地质模型。研究表明: (1)无人机倾斜摄影采集处理后数据模型具有三维坐标(经度、纬度和海拔)及对应的图像信息,可以准确定位并测量任意位置点坐标,为建立精准的地质知识库奠定了良好的基础;(2)对露头区储集层骨架与地质统计学参数进行了统计,建立了典型露头区地质知识库,主要包括储集层成因、砂体连续性与规模、砂体数量与相对比例、砂体几何形态和变差函数等参数;(3)在虚拟井位设置、岩性标定和储集层地质知识库的指导下,利用地质统计学变差函数的方法,建立了典型露头区三维地层-构造模型和2套岩性模型,模型与地质认识较为一致。

3D outcrop geological modeling based on UAV oblique photography data:A case study of Pingtouxiang section in Lüliang City,Shanxi Province

The conventional data acquisition methods of outcrop knowledge database have many limitations. The unmanned aerial vehicle(UAV)oblique photography,however,has many advantages including agility,global perspective and high quantificational degree,and therefore was used in this study to collect,process,and interpret the outcrop data of Pingtouxiang section in Lüliang City Shanxi Province. By establishing an outcrop geological knowledge database,a 3D outcrop geological model was developed. Main findings of this study were summarized as follows. (1)The data model developed after UAV oblique photography acquisition and processing has 3D coordinates(latitude,longitude,altitude),and contains corresponding image information. This allows the coordinates of any position to be accurately determined,providing a solid foundation to develop a precise geological knowledge database. (2)The architecture and geostatistical parameters of the outcrop reservoir were statistically analyzed,and a typical geological knowledge database of the outcrop area was developed. Main parameters in the database include formation mechanisms of reservoirs,the continuity,dimension,number,proportion,geometry,and variations of sand bodies,etc.;(3)According to the setting of virtual well location,lithology calibration,and reservoir geological knowledge database,a typical 3D stratigraphic-structural model and two sets of lithological models in the outcrop areas were developed using the geostatistical variogram function.