致密砂岩储层岩石物理建模及“甜点”预测  

Research on rock physical modeling and“sweet spot”prediction methods for tight sandstone reservoirs

作　　者：周雨晴 张佳佳[1] 张广智[1] 蔺营 ZHOU YuQing;ZHANG JiaJia;ZHANG GuangZhi;LIN Ying(China University of Petroleum(East China),Qingdao 266580,China)

机构地区：[1]中国石油大学(华东),青岛266580

出　　处：《地球物理学进展》2025年第1期255-265,共11页Progress in Geophysics

基　　金：国家自然科学基金(42074136)资助.

摘　　要：近些年来我国的致密砂岩气产量不断攀升,如何根据致密砂岩储层低孔低渗的特征,分析储层内部“甜点”成为了关键问题.本文首先通过对致密砂岩岩石物理特征进行分析,聚焦致密砂岩孔隙结构连通性,针对性地建立了致密砂岩岩石物理模型.然后结合实际工区特点,根据孔隙度、纵波阻抗等参数划分地球物理“甜点”进行敏感参数分析,得出体积模量与剪切模量之比(K/μ)以及纵横波速度比等致密砂岩储层“甜点”敏感参数,为后续叠前地震反演“甜点”奠定基础.最后,基于弹性阻抗反演推导适用于致密砂岩“甜点”敏感参数的反射系数方程,根据纵波模量与“甜点”敏感参数实现Ⅰ类“甜点”对Ⅱ类“甜点”(粗粒岩相)的定量预测,有效指示含气储层区域,为低渗致密砂岩储层的评价和开发提供了参考.In recent years,the production of tight sandstone gas in China has been rising,how to analyze the internal“sweet spot”of tight sandstone reservoir based on the characteristics of low porosity and low permeability has become a key issue.In this paper,the petrophysical model of tight sandstone is established by analyzing the petrophysical characteristics of tight sandstone and aggregating the pore structure connectivity of tight sandstone.Then,combined with the characteristics of the actual work area,the geophysical“sweet spot”are divided according to the porosity,P-wave impedance and other parameters.The sensitive parameters of“sweet spot”of tight sandstone reservoir,such as the ratio of bulk modulus to shear modulus(K/μ)and the ratio of P-wave velocity to S-wave velocity,are obtained,which lay a foundation for subsequent pre-stack seismic inversion for“sweet spot”.Finally,the reflection coefficient equation applicable to the sensitive parameters of tight sandstone“sweet spot”is derived based on the elastic impedance inversion,and the quantitative prediction of classⅠsweet spot to classⅡsweet spot(coarse-grained rock facies)is realized according to the P-wave modulus and the sensitive parameters of“sweet spot”,which effectively indicates the gas-bearing reservoir area and provides a reference for the evaluation and development of low permeability tight sandstone reservoir.

关 键 词：致密砂岩 “甜点”类型 岩石物理模型 弹性阻抗反演 

分 类 号：P631[天文地球—地质矿产勘探]