莺歌海盆地乐东区低渗透砂岩储层横波时差预测方法研究  

Prediction Method of Shear-wave Slowness of Low-permeability Sandstone Reservoir in Ledong Area of Yinggehai Basin

作　　者：张冠杰 何小胡 雷新 刘敬寿 王静[1] ZHANG Guanjie;HE Xiaohu;LEI Xin;LIU Jingshou;WANG Jing(School of Earth Science and Technology,China University of Petroleum(East China),Qingdao 266555,Shandong China;Zhanjiang Branch of CNOOC(China)Co.Ltd.,Zhanjiang 524057,Guangdong China)

机构地区：[1]中国石油大学(华东)地球科学与技术学院,山东青岛266555 [2]中海石油(中国)有限公司湛江分公司,广东湛江524057

出　　处：《河南科学》2021年第11期1790-1796,共7页Henan Science

基　　金：国家科技重大专项(2017ZX05001003-004);中国科学院先导科技A类专项(XDA14010301);山东省自然科学基金资助项目(ZR2020QD035);中国博士后面上基金(2019M662464)。

摘　　要：莺歌海盆地乐东区低渗透砂岩储层的岩石力学参数不清晰导致该区天然气的勘探开发受到制约.纵、横波时差的精确预测是求取岩石力学参数的关键,但该区实际生产过程中普遍缺乏横波时差这一重要地球物理资料.基于这一实际情况,本研究分别采用实测纵横波资料拟合模型和Xu-Whit模型对莺歌海盆地乐东区低渗透砂岩储层的横波时差进行了预测,同时对两种模型的预测结果进行了对比.在此基础上,利用Xu-White模型预测的横波时差对莺歌海盆地乐东区低渗透砂岩储层的岩石力学参数进行了计算.结果表明:利用实测纵横波资料拟合模型预测的横波时差存在较大误差,难以满足下一步的勘探开发要求;Xu-White模型是基于密度曲线、泥质含量以及孔隙度等实际资料对横波时差进行预测的,预测精度较高,可满足下一步的勘探开发要求;经计算,莺歌海盆地乐东区低渗透砂岩储层的动态杨氏模量在20~50 GPa之间,动态泊松比在0.1~0.3之间,内摩擦角在20°~40°之间,抗张强度在15~30 MPa之间.本研究可为莺歌海盆地乐东区的地应力场模拟以及目的层优化压裂设计提供可靠的岩石力学参数,对该区低渗透砂岩储层天然气开发的地质工程一体化也具有重要意义.Natural gas exploration and development in Ledong area of Yinggehai Basin are restricted by the insufficiency of rock mechanical parameters of low-permeability sandstone reservoir of Ledong area.Precise prediction of compressional wave and shear wave time differences is the key to solve rock mechanical parameters,but geophysical data of shear wave time difference is generally deficient during actual production in this region.In this study,given the above situation,the measured compressional wave and shear wave data fitting model and the Xu-White model were used to predict the shear wave time difference of low-permeability sandstone reservoirs in Ledong area,and the predicted results from the two models were compared.On this basis,the shear wave time difference predicted by the Xu-White model was used to calculate the rock mechanical parameters of low-permeability sandstone reservoir in Ledong area.The shear wave time difference predicted by the fitting model had a large error,which could not satisfy the requirements for subsequent exploration and development.In comparison,the Xu-White model could predict shear wave time difference by using real data,including density curves,argillaceous concentrations and porosity,and thus its high prediction precision could satisfy the requirements for subsequent exploration and development.Computations demonstrated the dynamic Young’s modulus,dynamic Poisson’s ratio,internal friction angle and tensile strength of low-permeability sandstone reservoir in Ledong area of Yinggehai Basin were 20-50 GPa,0.1-0.3,20°-40°and 15-30 MPa respectively.This study provides reliable rock mechanical parameters for ground stress field simulation and target stratum optimized fracturing design in Ledong area of Yinggehai Basin,and it is valuable for geological engineering integration of natural gas exploitation in the low-permeability sandstone reservoir of this region.

关 键 词：乐东区 横波时差预测 低渗透砂岩储层 XU-WHITE模型 岩石力学参数 

分 类 号：P631[天文地球—地质矿产勘探]