基于扩展方位弹性阻抗的裂缝参数及地应力参数预测方法  

Estimation of fracture parameters and in-situ stress parameter based on extended azimuthal elastic impedance

作　　者：李林[1,2] 张广智 LI Lin;ZHANG GuangZhi(Key Laboratory of Deep Oil and Gas in China University of Petroleum(East China),Qingdao 266580,China;School of Geosciences in China University of Petroleum(East China),Qingdao 266580,China)

机构地区：[1]中国石油大学(华东)深层油气重点实验室,青岛266580 [2]中国石油大学(华东)地球科学与技术学院,青岛266580

出　　处：《地球物理学报》2022年第8期3172-3185,共14页Chinese Journal of Geophysics

基　　金：国家自然科学基金项目(U19B2008,U19B6003,42074136,41674130);中国石油大学研究生创新工程项目(YCX2021016)联合资助。

摘　　要：裂缝参数及水平应力差异比(DHSR)的准确估测对于裂缝预测及水力压裂具有重要意义.扩展弹性阻抗是一种预测弹性参数及物性参数的有效方法,但其并未考虑各向异性的影响,本文将其推广到水平横向各向同性(HTI)介质中,提出一种基于扩展方位弹性阻抗的裂缝参数及DHSR预测方法.首先推导HTI介质中的扩展方位弹性阻抗方程及傅里叶系数方程,分析表明扩展方位弹性阻抗的二阶傅里叶系数与裂缝参数及DHSR相关性较好.其次,提出一种柯西稀疏约束和平滑模型约束正则化的贝叶斯地震反演来估测截距阻抗、梯度阻抗及曲率阻抗.最终,结合最优的旋转角和扩展方位弹性阻抗的二阶傅里叶系数实现裂缝参数及DHSR预测.模型测试和实际应用表明,该方法能够得到合理可靠的裂缝参数及DHSR预测结果,有助于指导裂缝发育区域及有利压裂区域的横向识别.Accurate estimation of fracture parameters and Differential Horizontal Stress Ratio(DHSR)is of great significance for subsurface fracture prediction and hydraulic fracturing.Extended Elastic Impedance(EEI)is an effective tool for the estimation of elastic parameters and physical parameters in isotropic media.However,EEI in isotropic media does not consider the influence of anisotropy.Here,we extend the EEI in isotropic media to Horizontal Transverse Isotropic(HTI)media,introduce the concept of Extended Azimuthal Elastic Impedance(EAEI),and propose a novel approach to estimate fracture parameters and DHSR using the Fourier Coefficient(FC)of EAEI.First,we derive the EAEI equation and FCs equation in HTI media.The analysis shows that the second FC of EAEI has a good correlation with fracture parameters and DHSR.Secondly,we propose a novel seismic Bayesian inversion with the regularization of the Cauchy-sparse constraint and smoothing model constraint to estimate intercept impedance,gradient impedance,and curvature impedance.Finally,we integrate the optimal rotation angles and the second FC of EAEI to estimate fracture parameters and DHSR,respectively.A synthetic data example and a field data application show that the proposed approach can provide reasonable and reliable inversion results of fracture parameters and DHSR,which help to guide the lateral identification of fracture development areas and favorable fracturing areas.

关 键 词：扩展方位弹性阻抗 傅里叶系数 裂缝参数 水平应力差异比 贝叶斯地震反演 

分 类 号：P631[天文地球—地质矿产勘探]