致密储层横波速度预测方法研究——以苏里格气田为例  

Research on predicting S-wave velocity in tight reservoir: Sulige gas field for example

作　　者：王浩璠 马劲风[1] 李琳[1] 王大兴 王永刚[2] WANG Hao-fan;MA Jin-feng;LI Lin;WANG Da-xing;WANG Yong-gang(National and Local Joint Engineering Research Center of Carbon Capture and Storage Technology,Department of Geology,Northwest University,Shaanxi,Xi'an 710069,China;Exploration and Development Research Institute of PetroChina Changqing Oilfield Company,Shaanxi,Xi'an 710018,China;National Engineering Laboratory for Exploration and Development of Low-Permeability Oil and Gas Field,Shaanxi,Xi'an 710018,China)

机构地区：[1]二氧化碳捕集与封存技术国家地方联合工程研究中心,西北大学地质学系,西安710069 [2]中石油长庆油田分公司勘探开发研究院,西安710018 [3]低渗透油气田勘探开发国家工程实验室,西安710018

出　　处：《地球物理学进展》2019年第4期1521-1529,共9页Progress in Geophysics

基　　金：国家高技术研究发展计划(863)课题“二氧化碳地质封存关键技术”(2012AA050103)资助

摘　　要：针对现有的岩石物理方法对致密砂岩储层横波速度预测误差较大,利用横波速度进行弹性阻抗反演、AVO反演识别致密油气有利分布区域误差较大的问题,本文提出了一种以实测横波速度约束的更高精度的致密砂岩横波速度预测方法.利用Xu-White模型预测横波速度时,孔隙纵横比是一个重要的参数,前人多采用固定的砂岩、泥岩孔隙纵横比,而整个储层不同深度上砂岩、泥岩的孔隙形状会发生改变,孔隙纵横比的值也随之改变.本文在确保实测横波速度与预测横波速度误差最小的前提下,由泥质含量曲线拟合了深度上逐点计算泥岩孔隙纵横比的计算公式,使得孔隙纵横比更加符合储层内垂向孔隙变化特征,预测的横波速度曲线平均误差为5.1%,较常规方法获得了更高精度的横波速度曲线.The prediction error of the S-wave velocities in tight sandstone reservoirs is relatively large when using the existing petrophysical method,which leads to the large deviation in elastic impedance inversion or AVO inversion to identify the favorable area distribution of tight oil and gas.In that case,we proposed a more accurate prediction method for predicting S-wave velocities in tight reservoir which based on constrained by the measured S-wave velocities.The pore aspect ratio played an important role when using Xu-White model to predict S-wave velocities.Previous researchers may adopt a constant sand pore aspect ratio and shale pore aspect ratio.However,the pore shape of sandstone and mudstone at different depths of the whole reservoir will change,that make the value of the pore aspect ratio changed.In this paper,under the premise of ensuring the error between the measured Swave velocities and the predicted S-wave velocities are minimum,we fitted the computational formula to calculated shale pore aspect ratio by shale content curves in depth domain point by point.So that the pore aspect ratio are more consistent with the characteristics of vertical pore change in reservoir.The average error of the predicted S-wave velocities is 5.1%,which improves the accuracy of the Swave velocities prediction compared with conventional method.

关 键 词：横波速度预测 XU-WHITE模型 泥岩孔隙纵横比 致密砂岩储层 

分 类 号：P631[天文地球—地质矿产勘探]