摘要
准噶尔盆地风城组页岩油储层是近期页岩油气勘探的重点,偶极声波测井显示各向异性较强,这与岩心发育微裂缝以及有一定程度的层理的情况比较吻合.目前,还不明确该储层基质的各向异性特征和机理,无法分析基质的矿物定向排列对页岩油偶极声波各向异性的贡献.应用实验测量了20块不含裂缝的页岩在地层条件下的声速各向异性,并结合薄片鉴定、X衍射以及孔隙度数据分析了其成因.实验研究发现:风城组页岩油储层基质的纵波各向异性系数在0~0.17之间,横波各向异性系数在0.01~0.16之间,椭圆度系数在0.008~0.11之间,呈现中等程度偏弱的各向异性特征;凝灰岩和凝灰质砂岩基质的各向异性总体较弱,微晶-泥晶白云岩基质的各向异性略大,粉晶白云岩基质的各向异性最大,方解石、长英质+方解石与火山灰+方解石的分层排列造成页岩基质的各向异性的主要原因;Thomsen系数与孔隙度存在一定的负相关关系,将Thomsen系数/孔隙度的比值作为新各向异性系数可以减弱孔隙度对各向异性系数的影响;微晶-泥晶白云岩等三类页岩基质的新横波各向异性系数与新纵波各向异性系数之间存在良好的正线性相关关系.研究可以为应用测井评价各向异性以及地震反演提供实验支持.
The shale oil of Fengcheng formation is key target of exploration and development in Junggar Basin.Dipole acoustic logging shows strong anisotropy which matches the massive microfractures and small amount beddings in core.So far,we do not know the anisotropic characteristics and mechanism of shale oil matrix so that we can't understand the contribution of shale oil matrix through the orientation arrangement of minerals.We measured the velocity anisotropy of 20 samples and analyzes the mechanism.The results showed a weak anisotropy:the range ofεwas from 0 to 0.17,the range ofγwas from 0.01 to 0.116 and the range ofζwas from 0.008~0.11.The tuff and tuffaceous sandstone had the weakest anisotropy and crystal powder dolomite had the strongest anisotropy.The mechanism was the orientation arrangement of calcite,felsic mineral and calcite,and cinerite and calcite.There was negative correlation between anisotropic parameter and porosity.Thus,it is necessary to define new anisotropic parameters by divided by porosity in order to eliminate the effect of porosity.There was positive correlation betweenεandγfor all types of shale.This study can be used for comprehensive interpretation of well logging and seismic inversion.
作者
王伟
王振林
陈山河
刘鹏
韩学辉
WANG Wei;WANG ZhenLin;CHEN ShanHe;LIU Peng;HAN XueHui(Research Institute of Petroleum Exploration and Development,Xinjiang Oilfield Company of PetroChina,Karamay 834000,China;School of Geoscience,China University of Petroleum(East China),Qingdao 266580,China)
出处
《地球物理学进展》
北大核心
2025年第5期2105-2113,共9页
Progress in Geophysics
基金
中国石油天然气集团有限公司科技项目“陆相页岩油地球物理建模关键技术研究”(2023ZZ15YJ02)
天山英才(2022TSYCJC0027)
国家自然科学基金(U1562108)联合资助。
关键词
页岩
各向异性
基质
声速
实验
Shale
Anisotropy
Matrix
Velocity
Experiment
