致密储层敏感弹性参数叠前同步反演方法  

A prestack simultaneous inversion method for sensitive elastic parameters of tight reservoir

作　　者：桂金咏[1,2] 高建虎[1] 雍学善[1] 李胜军[1] 李海亮[1] 

机构地区：[1]中国石油天然气股份有限公司勘探开发研究院西北分院,甘肃兰州730020 [2]中国石油天然气集团公司油藏描述重点实验室,甘肃兰州730020

出　　处：《石油物探》2015年第5期541-550,共10页Geophysical Prospecting For Petroleum

基　　金：国家科技重大专项"大型油气田与煤层气开发"专题(2011ZX05007-006)资助

摘　　要：杨氏模量和泊松比是表征致密储层脆性的重要弹性参数,而Gassmann流体项则是地震流体识别中常用的流体因子。利用叠前地震反演方法从叠前地震资料中同步获取此类参数是可行且有效的途径。为此,针对致密储层预测及流体识别的需要,提出了一种致密储层敏感弹性参数叠前同步反演的新方法。在孔隙弹性介质反射系数近似方程的基础上,通过重新组合变化,推导出包含杨氏模量、泊松比、Gassmann流体项及密度参数的纵波反射系数方程,建立起了杨氏模量、泊松比、Gassmann流体项及密度反射率与纵波反射系数间的线性关系。在此基础上,采用基于贝叶斯理论的弹性阻抗反演技术,提出了杨氏模量、泊松比、Gassmann流体项及密度参数的叠前同步反演方法。模型数据试算和实际资料测试结果均表明,所提出的方法能够从叠前地震资料中稳定地获取致密储层的敏感弹性参数,为此类储层的预测及流体识别提供了一种可靠的技术途径。Young＇ s modulus and Poisson＇ s ratio are the important elastic parameters representing the brittleness of tight res- ervoir rock, and Gassmann＇s fluid item is regarded commonly as a fluid factor in seismic fluid identification. Prestack seismic inversion is a feasible and effective way to obtain such parameter from prestack seismic data. For the tight reservoir prediction and fluid identification, a new prestack simultaneous inversion method for sensitive elastic parameters of tight reservoir is proposed. Based on the pore elastic reflection coefficient approximate equation, we derive a P-wave reflection parameter equation of Young＇s modulus, Poisson＇s ratio, Gassmann＇s fluid item and density. On this basis, a prestack simultaneous inversion method for sensitive elastic parameters of tight reservoir is constructed using the elastic impedance inversion technique based on Bayesian inversion framework. Model and actual data tests show that the newly proposed prestack simultaneous method can robustly obtain sensitive elastic parameters of tight reservoir from prestack seismic data, which offers a reliable technical approach for the tight reservoir prediction and fluid identification.

关 键 词：致密储层 杨氏模量 泊松比 流体项 叠前同步反演 

分 类 号：P631[天文地球—地质矿产勘探]