基于孔裂隙储层弹性参数频散衰减机理的有限元数值模拟  

Finite element numerical simulation for dispersion and attenuation of elastic parameters in fractured porous reservoirs

作　　者：张家良[1] 魏朋朋[1] 张会卿[1] 张孟凡 李皓 贺艳晓[2] 李国发[2] ZHANG Jialiang;WEI Pengpeng;ZHANG Huiqing;ZHANG Mengfan;LI Hao;HE Yanxiao;LI Guofa(Exploration and Development Research Institute,PetroChina Dagang Oilfield Company,Tianjin 300280,China;School of Geophysics,China University of Petroleum(Beijing),Beijing 102249,China;Yangtze Delta Region Institute(Huzhou),University of Electronic Science and Technology of China,Zhejiang Huzhou 313001,China)

机构地区：[1]中国石油大港油田分公司勘探开发研究院,天津300280 [2]中国石油大学(北京)地球物理学院,北京102249 [3]电子科技大学长三角研究院(湖州),浙江湖州313001

出　　处：《非常规油气》2024年第2期56-65,共10页Unconventional Oil & Gas

基　　金：中国石油天然气股份有限公司重大科技专项“中高渗油田特高含水期大幅度提高采收率技术研究”(2023zz22);北京市自然科学基金项目“深层致密油藏地震频段岩石物理实验、理论及应用研究”(8222073)。

摘　　要：饱含流体孔隙裂隙储层介质的弹性参数频变特性常应用于地震勘探和储层评价中。针对传统有效介质理论不准确及计算精度不高的问题,该研究推导了适用于孔隙弹性储层的Biot固结方程;为了研究模型介质渗透率、流体类型和黏度等参数对频变弹性参数的影响机理,开发了相应的有限元数值模拟流程,用于计算由波致流引起的地震波速度频散及衰减。模拟结果表明:1)与现有岩石物理理论模型对比,该数值模拟方法在宽频段模拟一维/二维孔隙裂隙介质的适用性更好;2)渗透率、流体黏度以及流体饱和模式作为岩心重要的物性表征,显著影响地震波弹性响应,渗透率增大,特征频率右移;黏度增大,特征频率左移;水包气模型相对于油包气模型衰减峰值较大,特征频率略高。综上所述,该研究为深入理解地震波在孔裂隙储层中的传播特性提供了准确的预测方法,有助于揭示储层的非均质性和孔隙结构,提高勘探精度和储层评价的可靠性,对储层预测与流体识别的岩石物理解释具有重要的指导意义。The frequency-varying properties of elastic parameters of fluid-saturated fractured porous reservoir media are often applied in seismic exploration and reservoir evaluation.Due to the inaccuracy and lack of precision of the traditional effective medium theory,this study derives the Biot consolidation equation applicable to poroelastic reservoirs and develops a corresponding finite element numerical simulation for calculating the dispersion and attenuation of seismic wave velocity induced by the wave-induced flow,and studying the mechanism of the influence of parameters such as permeability of the model medium,fluid type and viscosity on the frequency-varying elastic parameters.The simulation results show that:1)In comparison with existing theoretical petrophysical models,this numerical simulation method is more suitable for simulate 1D/2D fractured porous media in a wide band;2)The permeability,fluid viscosity,and fluid saturation mode,which are the important physical parameters of the core,significantly affect the elastic response of seismic wave.The characteristic frequency shifts to the right if permeability increases,and the characteristic frequency shifts to the left if viscosity increases.The gas-in-water model has a larger attenuation peak and slightly higher eigenfrequency than the gas-in-oil model.In summary,this study provides an accurate prediction method for the further understanding of the propagation characteristics of seismic waves in fractured porous reservoirs,which helps to reveal the nonhomogeneity and pore structure of reservoirs,improve the exploration accuracy and reliability of reservoir evaluation,and has important guiding significance for the petrophysical interpretation of reservoir prediction and fluid identification.

关 键 词：频散与衰减 孔裂隙介质 数值模拟 岩石物理 流体流动 

分 类 号：P618.13[天文地球—矿床学]