摘要
砾石磨圆度表征对分析砂砾岩地层的沉积相具有重要意义。通过砾石颗粒截面面积和周长2个参数计算得到的砾石的磨圆度值,进一步数值标准化后进行磨圆度定量表征,以研究玛湖凹陷三叠系百口泉组砂砾岩磨圆度特征,进而分析其沉积相。研究结果表明:①砾石磨圆度测量过程包括划分测量单元、砾石图像提取和形态参数计算等3个步骤,然后进行去扁化磨圆度定量计算,最后进行磨圆度定量分级。②玛15井第2回次取心砾石的磨圆度整体较第3回次取心好,2次取心圆球形和椭球形砾石占比分别为19.89%和38.98%。第2回次取心砾石Rdn值呈减小趋势,磨圆度整体向上变差,从次圆状变为次棱—次圆状;第3回次取心砾石Rdn值从下部向上逐渐变大,磨圆度整体向上变好,从次棱角状变为次棱—次圆状。③玛15井百二段从底到顶,沉积相从三角洲平原季节性辫状河道过渡为三角洲平原常年性辫状河道,与砾石磨圆度由次棱变为次棱—次圆的变化相对应。
The gravel roundness characterization is important for facies analysis of sandy conglomerate strata.Based on the two parameters of gravel particle cross-sectional area and perimeter,the calculated roundness value was normalized to carry out quantitative characterization of roundness,so as to study the roundness characteristics of sandy conglomerates of Triassic Baikouquan Formation in Mahu Sag,and then analyze its sedimentary facies. The results show that:(1)The gravel roundness measurement process includes three steps:dividing the measurement unit,extracting the gravel image and calculating the morphological parameters,then the quantitative calculation of the de-flat roundness was completed,and finally the quantitative classification of the roundness was carried out.(2)The roundness of the gravel in the second coring of well Ma 15 is better than that in the third coring. The spherical and ellipsoidal gravel accounts for 19.89% and 38.98% respectively. The Rdnvalue of the second coring gravel shows a decreasing trend,and the roundness becomes worse as a whole,from subrounded to sub-angular and sub-rounded. The Rdnvalue of the third coring gravel gradually increases from the lower part to the upper part,and the roundness becomes better as a whole, from sub-angular to sub-angular and sub-rounded.(3)From the bottom to the top,the sedimentary facies of the second member of Baikouquan Formation of well Ma 15 transits from seasonal braided channel of delta plain to perennial braided channel of delta plain,corresponding to the change of gravel roundness from sub-angular to sub-angular and sub-rounded.
作者
彭妙
张磊
陶金雨
赵康
张祥辉
张昌民
PENG Miao;ZHANG Lei;TAO Jinyu;ZHAO Kang;ZHANG Xianghui;ZHANG Changmin(PetroChina Xinjiang Oilfield Company,Karamay 834000,Xinjiang,China;Research Institute of Exploration and Develop-ment,PetroChina Xinjiang Oilfield Company,Karamay 834000,Xinjiang,China;Wuxi Research Institute of Petroleum Geology,Research Institute of Petroleum Exploration&Production,Sinopec,Wuxi 214131,Jiangsu,China;School of Geosciences,Yangtze University,Wuhan 430100,China)
出处
《岩性油气藏》
CAS
CSCD
北大核心
2022年第5期121-129,共9页
Lithologic Reservoirs
基金
国家自然科学基金项目“中国西部主要盆地周缘及邻区分支河流体系分布与沉积模式”(编号:41772094)
中国石油天然气股份有限公司科技重大专项“陆相中高成熟度页岩油勘探开发关键技术研究与应用”(编号:2019E-2601,2019E-2602)联合资助。
关键词
定量表征
砾石磨圆度
去扁度方法
百口泉组
三叠系
玛湖凹陷
quantitative characterization
gravel roundness
de-flat roundness
Baikouquan Formation
Triassic
Mahu Sag
