基于Zoeppritz方程的纵横波联合反演方法及应用  

The joint PP-and PS-wave inversion method based on the Zoeppritz equations and its application

作　　者：胡鑫 王国权[3] 刘俊洲 支丽霞 陈双全 HU Xin;WANG Guoquan;LIU Junzhou;ZHI Lixia;CHEN Shuangquan(State Key Laboratory of Shale Oil and Gas Enrichment Mechanism and Effective Development,Beijing 100083,China;Sinopec Key Laboratory of Elastic Wave Theory and Detection Technology,Beijing 100083,China;CNPC Key Laboratory of Geophysical Exploration,China University of Petroleum-Beijing,Beijing 102249,China;College of Science,China University of Petroleum-Beijing,Beijing 102249,China)

机构地区：[1]页岩油气富集机理与有效开发国家重点实验室,北京100083 [2]中国石化弹性波理论与探测技术重点实验室,北京100083 [3]中国石油大学(北京)CNPC物探重点实验室,北京102249 [4]中国石油大学(北京)理学院,北京102249

出　　处：《石油科学通报》2022年第4期515-531,共17页Petroleum Science Bulletin

基　　金：国家重点研发计划(2018YFA0702505);国家自然科学基金企业创新发展联合基金(U19B6003-004);国家自然科学基金面上项目(41574108,42174130);中国石化弹性波理论与探测技术重点实验室开放基金(33550000-21-FW0399-0016)的联合资助。

摘　　要：利用叠前道集数据进行叠前地震反演已经成为油藏储层预测及流体检测常用的技术手段。特别是对于致密油气、页岩油气等非常规油气藏的勘探开发,利用叠前地震反演进行地球物理“甜点”储层预测与描述是研究的热点及难点。常用的叠前地震反演方法是基于Zoeppritz方程的线性化近似式,且主要利用反射纵波数据。考虑到近似方程有着小角度入射的条件限制,对远偏移距数据不适用,而远偏移距数据有利于提高弹性参数反演精度,正演时近似方程与精确Zoeppritz方程存在误差,反演过程中累计误差会降低反演精度,因此使用精确Zoeppritz方程可以有效提高反演精度。为了提高叠前地震反演的适定性,本文提出了利用精确Zoeppritz方程解析表达式的反演方法,避免引入Zoeppritz方程近似式的限制条件,极大提高了叠前地震反演的精度,同时反演中联合使用了反射纵波及转换波数据。联合纵波与转换波数据进行反演,通过增加地震叠前反演中的输入信息,提高反演结果的准确度。而且,基于精确Zoeppritz方程的纵横波联合反演得到更准确的纵波速度、横波速度和密度三个参数,可以更好地对油气藏储层进行描述,确定油气藏的有利“甜点”区。同时,反演计算中采用IRLM方法,解决叠前多参数反演的强非线性和不适定问题,提高IRLM反演方法的抗噪能力。最后,通过合成数据及实际数据的应用,反演结果验证了反演方法的适用性,而且该方法抗噪性强,能够进行实际数据的应用。Prestack seismic inversion using prestack seismic gather data has become a commonly used technical method for reservoir prediction and fluid detection. In particular, for the exploration and development of unconventional oil and gas reservoirs such as tight reservoirs, shale reservoirs, the prediction and description of geophysical "sweet spot" reservoirs by using the prestack seismic inversion is an important topic and a difficult problem in research. The commonly used prestack seismic inversion method is a linearized approximation based on the exact Zoeppritz equations, and mainly uses the reflected compressional wave data. Considering that the approximate equation has the condition limitation of small incident angle in the prestack seismic inversion, it is not applicable to the far offset data, while the far offset data is conducive to improving the inversion accuracy of the elastic parameters. There is an error between the approximate equations and the exact Zoeppritz equations during forward modelling, and the accumulated error during the inversion process will reduce the inversion accuracy, so the use of the exact Zoeppritz equations can effectively improve the inversion accuracy. In order to improve the suitability of prestack seismic inversion, an inversion method using the exact Zoeppritz analytical expression is proposed, avoiding the introduction of condition constraints which are approximated by the exact Zoeppritz equations and greatly improving the accuracy of prestack seismic inversion. Moreover, the reflected compressional wave data and the converted wave data are used in the prestack seismic inversion. The inversion of reflected compressional wave data and converted wave data is combined to improve the accuracy of the inversion result by increasing the input information in the prestack seismic inversion. Besides, the joint inversion of the reflected compressional wave data and the converted wave data based on the exact Zoeppritz equations can obtain more accurate parameters of compressional wave

关 键 词：ZOEPPRITZ方程 线性化反演 转换波 联合反演 正则化方法 

分 类 号：P618.13[天文地球—矿床学] P631.4[天文地球—地质学]