叠前声波方程反演及其应用  

Pre-stack Acoustic Equation Inversion and Its Application

作　　者：李国平[1] 石玉梅[1] 姚逢昌[1] 曹宏[1] 

机构地区：[1]中国石油勘探开发研究院

出　　处：《岩性油气藏》2010年第F07期147-149,162,共4页Lithologic Reservoirs

基　　金：中国石油天然气集团公司应用基础研究项目（编号：2008A-1803）资助.该研究得到了中国石油勘探开发研究院研究项目的支持,石玉梅在文章撰写过程中给予了很大支持.还有姚逢昌、曹宏、李永根等在研究过程中提供了帮助.在此一并表示感谢.

摘　　要：叠前波动方程反演是地球物理反演的重要发展方向，反演过程中利用了全波场信息，且反演出的弹性参数对预测地下储层的含油气性具有重要的参考价值。文中以Tarantola的全波形反演理论和波场回传技术为基础。推导出了声波方程反演的体积模量和密度扰动量公式，从而利用叠前炮集数据反演地层有效介质体积模量和密度。联合Gassmann方程和Kuster-Toksuz方程，对有效介质体积模量进行分解，获得流体模量。根据研究区域有效油气藏饱和度下限，确定模量法流体识别准则。叠前波动方程反演提供了可靠的地球物理参数。同时考虑了孔隙形状对介质弹性性质的影响，显著提高了地震流体识别的准确度。该方法在我国西部某致密砂岩气田的应用结果表明，其流体识别结果与钻探结果基本一致。The inversion of pre-stack wave equation is an important development direction of the geophysics inversion. It uses the full wave field information for the inversion. With Tarantola full waveform inversion theory and wave field return technology as the basis, volumetric module and density disturbance formulas for acoustic equation inversion was worked out. The effective medium volumetric module and density of formation was inverted through the data of pre-stack shot gather. With Gassmann equation and Kuster-Toksuz equation, the volumetric module of effective medium was divided to get fluid module. Based on the lower limit of saturation of effective reservoir of study area, fluid identification by module principle was confirmed. The method uses wave equation inversion to provide reliable geophysical parameters while considering influence of pore shape on property of elastic medium, which obviously improves the accuracy of fluid identification through seismic survey. The method was applied into tight sandstone reservoir in a certain gas field in western China. The result of fluid identification was basically consistent with drilling result.

关 键 词：波动方程反演 弹性参数 体积模量 密度 流体识别 

分 类 号：P631.4[天文地球—地质矿产勘探]