摘要
页岩油储层流体赋存状态多样、矿物成分复杂,导致各流体组分含量难以准确计算。为此,提出基于连续小波变换与高斯分布函数结合计算页岩油各流体组分含量的方法。基于聚焦离子束扫描电镜(FIB-SEM)实验结果,获得包含无机孔隙水、有机孔隙油、骨架、黄铁矿以及有机质的页岩多组分数字岩心。利用随机游走方法模拟数字岩心在不同回波间隔时的核磁共振回波串,将其反演得到无机孔隙水、有机孔隙油和有机质的核磁共振T_(2)分布以及所有组分(无机孔隙水、有机孔隙油和有机质)的核磁共振T_(2)分布。利用连续小波变换处理所有组分的T_(2)分布,得到二维小波系数矩阵,对其谱峰进行识别获得小波空间中不同尺度谱峰的位置参数和形状参数,构造不同尺度的高斯分布函数,对T_(2)分布进行分解,选取最优分解结果来计算各流体组分的含量。对比不同回波间隔时该方法计算的各流体组分含量与基于随机游走方法模拟得到的各流体组分含量,结果表明:该方法的计算结果与基于随机游走方法模拟得到的各流体组分含量的绝对误差较低,验证了该方法的有效性。该方法可为页岩油的勘探开发提供技术支撑。
Shale oil reservoirs,characterized by the complex occurrence state of fluid and complex mineral compositions,are difficult to accurately determine the fluid component content.Therefore,a method to determine the fluid component content of shale oil combining with continuous wavelet transform(CWT)and Gaussian distribution function is proposed in this paper.Based on the focused ion beam scanning electron microscopy experiments,a digital shale core containing inorganic pore water,organic pore oil,matrix,pyrite,and organic matter is obtained.On this basis,the random walk method is used to simulate the nuclear magnetic resonance response of the pore fluids at different echo spacing.The echo data is inversed for the T_(2)distributions of inorganic pore water,organic pore oil,and organic matter as well as the T_(2)distribution of all fluid components.For the T_(2)distribution of all fluid components,the CWT is carried out,and a two-dimensional wavelet coefficient matrix can be obtained.By identifying spectral peaks,the positions and shape parameters of spectral peaks at different scales in the wavelet space are determined.The T_(2)distribution for all fluid components is decomposed by the constructed Gaussian distribution functions of different scales.The optimal decomposed result is used to calculate the fluid content of shale oil.The contents of fluid components calculated by proposed method with the numerical simulation based on random walk method at different echo spacing are compared.The result indicates that the absolute error between them is relatively low at different echo spacing.The effectiveness of the proposed method is verified.This method can provide technical support for the exploration and development of shale oil.
作者
刘继龙
谢然红
卫弘媛
徐陈昱
金国文
郑迪
王绍祥
LIU Jilong;XIE Ranhong;WEI Hongyuan;XU Chenyu;JIN Guowen;ZHENG Di;WANG Shaoxiang(College of Geophysics,China University of Petroleum(Beijing),Beijing 102249,China;Huabei Branch,China National Logging Corporation,Renqiu,Hebei 062550,China;Market Production Department,China National Logging Corporation,Xi’an,Shaanxi 710077,China)
出处
《测井技术》
CAS
2023年第5期533-541,共9页
Well Logging Technology
基金
国家自然科学基金项目“基于积分变换的核磁共振测井应用基础与多维谱反演方法研究”(42174131)
中国石油大学(北京)科研基金“基于积分变换的核磁共振测井评价方法研究”(2462022XKBH003)。
关键词
页岩油
核磁共振
数值模拟
连续小波变换
流体组分含量
shale oil
nuclear magnetic resonance
numerical simulation
continuous wavelet transform
fluid component content
作者简介
第一作者:刘继龙,男,1993年生,博士研究生,从事页岩油核磁共振数值模拟研究。E-mail:liujilong_cup@163.com;通信作者:谢然红,女,1966年生,教授,从事岩石物理、核磁共振测井方法及应用工作。E-mail:xieranhong@cup.edu.cn。
