摘要
煤层的形成及煤层气资源的富集很大程度上取决于聚煤盆地的沉积环境及其古地理特征,聚煤盆地古地理环境的三维空间恢复对于研究煤层气资源的赋存规律及勘探靶区优选至关重要。该文以沁水盆地南部柿庄南区块为研究区,提出基于多维测井数据的聚煤盆地古地理沉积环境三维空间定量恢复方法。首先利用K-means空间聚类方法对研究区煤系地层主要岩性的测井曲线响应特征进行聚类,由此定量识别单井岩性和划分岩层层序格架;进而结合各沉积单元的测井曲线形态特征和岩性组合特点,综合确定沉积环境层序;最后依据研究区1300余口钻井的沉积剖面序列实现聚煤盆地三维沉积相模型的精细构建。结果表明,研究区煤系地层山西组空间上为三角洲平原沉积体系特征,主要发育分流河道、分流间湾、天然堤、决口扇和泥炭沼泽5种沉积微相;泥炭沼泽沉积环境发育的3#煤层平均厚度为6.25 m,其三维空间聚集与覆水深度呈现一定相关性,空间上表现为沿海退方向上煤层逐渐变薄并具有分带特征;局部上受沉积环境影响,东南地区煤层煤质较好且顶部的泥岩、砂质泥岩较厚,有利于煤层气封存,为煤层气资源开发的有利靶区。
The formation of coal seams and the enrichment of CBM resources largely depend on the depositional environment and its paleogeographic features in the coal-accumulating basins,and the 3D spatial restoration of the paleogeographic environment in the coal-accumulating basins is crucial to the study of the coal-bed methane resources and the selection of exploration target areas.This paper investigated the three-dimensional spatial recovery method of the paleogeographic sedimentary environment of the coal-accumulating basin based on logging data with multi-dimensional spatial attributes,taking the Shizhuangnan Block in the southern Qinshui Basin as the experimental area.Firstly,the K-means spatial clustering method was used to cluster the response characteristics of the logging curves of the main lithologies of the coal-bearing strata in the study area,and the cluster results were used to quantitatively identify the lithologies of individual wells and delineate the lithological sequence framework.Then,combined with the morphological characteristics of logging curves and lithological combination characteristics of each sedimentary unit,the sedimentary environment sequence was comprehensively determined.Finally,the three-dimensional sedimentary phase model of the coal-accumulating basin was finely constructed based on the sedimentary profile sequences of more than 1300 wells.The model analysis shows that the Permian Shanxi Formation of coal-bearing strata in this study area is characterized by a deltaic plain sedimentary system,with five types of sedimentary micro-phases:distributary channel,distributary bay,natural levee,crevasse and peat swamp,and the average thickness of the 3#coal seam in the peat swamp sedimentary environment is 6.25 m.The coal seams in the coastal retrogression direction gradually become thinner and have zonation characteristics,and the coal quality of coal seams in the southeast area is relatively good due to the influence of sedimentary environment locally and the mudstone and sandy mudstone at the top are thicker and conducive to CBM sequestration,making it a favourable target area for CBM resource development.
作者
陈国旭
阮寅芝
李蕊蕊
刘盛东
李忠城
CHEN Guo-xu;RUAN Yin-zhi;LI Rui-rui;LIU Sheng-dong;LI Zhong-cheng(School of Resources and Environmental Engineering,Hefei University of Technology,Hefei 230009;State Key Laboratory of Deep Geomechanics&Underground Engineering,China University of Mining and Technology,Xuzhou 221008;China United Coalbed Methane Co.Ltd.,Beijing 100113,China)
出处
《地理与地理信息科学》
CSCD
北大核心
2023年第1期8-14,共7页
Geography and Geo-Information Science
基金
国家自然科学基金项目(41972304)
国家科技重大专项(2011ZX05060)。
关键词
古地理沉积环境
测井数据
K-MEANS聚类
岩性识别
三维沉积模型
paleogeographic sedimentary environment
logging data
K-means clustering
lithology identification
3D sedimentary model
