工程地质学报2019，Vol.27Issue(1)：69-79,11.DOI:10.13544/j.cnki.jeg.2019-061
考虑页岩纹层与裂缝网络的延长组页岩多尺度三维地质结构模型
MULTI-SCALE 3-D MODELING OF YANCHANG SHALE GEOLOGICAL STRUCUTRE CONSIDERING LAMINAS AND FRACTURE NETWORKS
摘要
Abstract
Outcrops and core observations show that sandy and tuff aceous laminas and natural fractures are well developed in the continental shale gas reservoir. This study reports the distribution of laminas and natural fracture networks at different scales and established the 3-D geological structure models, with data obtained from outcrops, wells and cores of Yanchang shale from southern Ordos Basin. Firstly, based on two-dimensional fracture field investigations, a 3-D joint network model of the study area was built using the Monte Carlo simulation method. Then the laminations were identified from macroscopic scales to microscopic scales with multiple probe techniques.Statistical analysis of multi-scale layer thickness suggested that the average thickness of layers at multiple scales showed a fractal feature, with average layer thickness of 2. 26 m, 2. 09 dm, 1. 70 cm, 1. 48 mm and 11. 7 μm, corresponding to meter scale, decimeter scale, centimeter scale, millimeter scale and 10-micro meter scale respectively, and that the layer thickness at studied scales all followed with an exponential probability distribution.The fitting curves indicated that most of laminas at each scale were relatively thin. In other words, the thicker the layer, the less the number of layers contained in shale. Finally, the lamination models were constructed and superposed over the joint network model to generate 3-D geological structure models at various scales. The models were validated by reproducing fracture and lamina parameters, which were fairly close to those measurements of realistic geological bodies in the study area. The findings of this work could shed light on the characterization and modeling of geological structure for the numerical simulation and physical model test of hydraulic fracturing in shale gas reservoir.关键词
纹层/裂缝网络/多尺度/地质结构模型/延长组页岩Key words
Lamina/Fracture network/Multi-scale/Geological structure model/Yanchang shale分类
天文与地球科学引用本文复制引用
李丽慧,黄北秀,李严严,邵鹏,高相波,胡瑞林,李晓..考虑页岩纹层与裂缝网络的延长组页岩多尺度三维地质结构模型[J].工程地质学报,2019,27(1):69-79,11.基金项目
中国科学院战略性先导科技专项 (B类) (XDB10030101) （B类）
国家自然科学基金项目 (41641025) 资助 （41641025）
