地质论评2025，Vol.71Issue(5)：1441-1460,20.DOI:10.16509/j.georeview.2025.02.002
鄂尔多斯盆地东南部山西组—下石盒子组8段三角洲砂体沉积特征及构型模式
Sedimentary characteristics and constitutive pattern of the deltaic sand body in Shanxi Formation—the 8th Member of Lower Shihezi Formation in southeastern Ordos Basin
摘要
Abstract
Objectives:The exploration and development of the Ordos Basin have progressed rapidly.With the deepening exploration of effective reservoir identification technology and the continuous advancement of quantitative characterization research,the southeastern part of the basin has demonstrated enormous exploration potential.Strengthening the understanding of sedimentary evolution in this region,clarifying the sedimentary sand body patterns in the southeastern part of the Ordos Basin,and analyzing their spatial combinations are of significant importance for the exploration and development of tight gas in the basin. Methods:Sedimentary characteristics in the study area were analyzed using methods such as petrographic observation,grain size analysis,and geochemical analysis.By identifying the configuration elements of the study area and combining well log data,a regression analysis was conducted to establish a discriminant formula for the configuration elements,enabling the qualitative and quantitative identification of configuration elements and constructing the three-dimensional distribution characteristics of configuration elements in the study area. Results:In the study area,9 major lithological types and 10 configuration elements were identified in the 2nd,and the 1st Member of the Lower Permian Shanxi Formation(the Shan-2 and Shan-1 Member)and the 8th Member of the Lower Shihezi Formation,Middle Permian(the He-8 Member).Fisher's discriminant formula for five configuration elements,submarine distributary channels,submarine distributary bay,mouth bars,sheet sand,and peat marshes,are established.Six stacking modes were identified:submarine distributary channel-submarine distributary channel,sheet sand-sheet sand,submarine distributary channel-sheet sand,distributary channel-distributary channel,mouth bar-mouth bar,submarine distributary channel-mouth bar. Conclusions:In the study area,the Shan-2 and Shan-1 Member developed meandering river delta front subfacies,and the He-8 Member developed braided river delta front subfacies and delta plain subfacies.Based on the discriminant formula for configuration elements,sand body configuration distribution models of the Shan-2 Member,the Shan-1 Member and the He-8 Member were established.The sand body configuration in the Shan-2 Member is mainly developed in submarine distributary channels,while the Shan-1 Member is dominated by submarine distributary channels and sheet sand,with frequent overlap between them.The He-8 Member is dominated by submarine distributary channels,mouth bars,and sheet sand,with a rich variety of sand body stacking patterns.关键词
鄂尔多斯盆地东南部/砂体构型/沉积特征/三角洲前缘/叠置特征/山西组/下石盒子组8段Key words
southeastern Ordos Basin/sand body configuration/stacking characteristics/delta front/sand body configuration distribution/Shanxi Formation/the 8th Member of Lower Shihezi Formation引用本文复制引用
王译羚,张成弓,虎建玲,杜佳宁,侯林君,陈洪德..鄂尔多斯盆地东南部山西组—下石盒子组8段三角洲砂体沉积特征及构型模式[J].地质论评,2025,71(5):1441-1460,20.基金项目
本文为中国石油天然气股份有限公司"十四五"前瞻性基础性科技项目(编号:2021DJ2101)、中石油长庆油田科研项目(编号:CQYT-CQKTY-2021-JS-2728,CQYT-CQKTY-2020-JS-62503)的成果. CNPC"Fourteenth Five Year Plan"Prospective Basic Science and Technology Project(No.2021DJ2101) （编号:2021DJ2101）
CNPC Research Project(Nos.CQYT-CQKTY-2021-JS-2728,CQYT-CQKTY-2020-JS-62503) （Nos.CQYT-CQKTY-2021-JS-2728,CQYT-CQKTY-2020-JS-62503）
