基于叠前地震道集的流体因子同步反演方法  

Prestack simultaneous inversion of fluid factors with prior constraints

作　　者：刘厚裕 白俊雨[2] LIU Houyu;BAI Junyu(Sinopec East Oil & Gas Company, Nanjing 200019,China;Sinopec Geopysical Research Institute,Nanjing 211103,China)

机构地区：[1]中国石油化工股份有限公司华东油气分公司,南京200019 [2]中国石油化工股份有限公司石油物探技术研究院,南京211103

出　　处：《物探化探计算技术》2021年第3期275-281,共7页Computing Techniques For Geophysical and Geochemical Exploration

基　　金：中国石化集团公司重点项目(P20056-1,PE19008-4)。

摘　　要：基于岩石物理理论建立的Gassmann流体因子能更好地区分多孔介质的流体和岩石基质,在储层预测及流体识别中获得了广泛地应用。现有技术中对常规叠前地震反演的弹性参数进行转换得到Gassmann流体因子的方法存在误差累计且预测精度不高。为此,建立一种Gassmann流体因子叠前地震道集反演方法,给出了叠前流体因子反演的目标泛函以及其梯度的解析解,为致密储层预测及流体识别提供重要参数。首先,综合考虑地震道集的数据匹配和流体因子的先验信息,建立先验信息约束的流体因子叠前反演目标泛函;然后,采用非线性最小二乘算法进行求解,对流体因子、剪切模量及密度进行同步联合反演。经过理论模型正演数据及井旁道集资料的反演应用,其结果表明,本文方法能够有效地反演流体因子,为从叠前地震资料挖掘更加丰富的地下介质信息提供了一种技术方法。Gassmann fluid factor has been widely used in reservoir prediction and fluid identification due to fact that it can better distinguish the fluid of porous media from rock matrix.A prestack seismic simultaneous inversion method has been established to invert Gassmann fluid factor,shear modulus and density from prestack angular gathers.In this paper,the objective functional of prestack fluid factor inversion and the analytical solution of its gradient are given.First,based on data matching of seismic gathers and prior information of fluid factors,a fluid factor of pre-stack inversion target function constrained by prior information is established.Then,the nonlinear least squares algorithm is used to solve the problem,and the simultaneous joint inversion of the fluid factor,shear modulus and density is performed.Finally,the inversion application of theoretical model data and well side gather data shows that the method proposed in this paper can effectively invert fluid factors,which provides a technical method for mining more abundant underground medium information from prestack seismic data.

关 键 词：岩石物理应用 叠前反演 先验约束 流体因子 流体因子反演 AVO反射系数 

分 类 号：P631.4[天文地球—地质矿产勘探]