基于叠前全方位角道集方位振幅梯度各向异性变化的HTI裂缝介质油气检测方法与技术  

Oil and gas detection method and technique of HTI fracture media based on the anisotropic variation of azimuth-amplitude gradient in prestack omni-directional incidence-angular gather

作　　者：刘军迎[1,2] 雍学善 张静[1,2] 罗瑞兰[2] LIU JunYing;YONG XueShan;ZHANG Jing;LUO RuiLan(Research Institute of Petroleum Exploration and Development Chinese Northwest Branch,Lanzhou 730020,China;Petrochina Research Institute of Petroleum Exploration&Development Research Center of Sichuan Basin,Chengdu 610094,China)

机构地区：[1]中国石油勘探开发研究院西北分院,兰州730020 [2]中国石油勘探开发研究院四川盆地研究中心,成都610094

出　　处：《地球物理学报》2021年第10期3807-3816,共10页Chinese Journal of Geophysics

摘　　要：高角度裂缝介质的反射振幅梯度是随方位变化的,常规AVO分析只能适应层状各向同性介质地下地层含油气性检测,很难适应HTI裂缝各向异性介质地层的油气检测.为此,本文提出了基于叠前全方位角道集方位振幅梯度各向异性变化的HTI裂缝介质油气检测方法,推导出以方位角为变量的方位振幅梯度变化函数,并以之为参变量进一步推导出以入射角为变量的,随方位变化而变化的双向振幅响应强度变化函数,同时推导出方位油气指示因子.通过变量拆分法先固定方位方向,通过该方位角道集振幅随入射角的变化求解该方位振幅梯度,继而求出该方位的油气指示因子;依次类推,可求出其余方位的油气指示因子.如此可求出所有方位的油气指示因子,进而可分析含油气指示敏感性随方位的变化,优选油气指示最敏感的方位作为最终的油气预测结果即可.实际工区应用结果表明,本方法预测结果可靠精度高,可为油气勘探开发提供有效的技术支持.The refelctive amplitude gradient along incidence-direction of high-dip-angle fracture media varies with azimuthal orientation.Conventional AVO analysis method can only adapt to the detection of oil and gas in layered isotropic media,but it is difficult to adapt to the detection of oil and gas in HTI fracture anisotropic media.This paper presents an oil and gas detection method and technique of HTI fracture media by the anisotropic variation of azimuth-amplitude gradient based on prestack omni-directional incidence-angular gather.A azimuthal orientation amplitude gradient function with the variable change of azimuth angle is deduced,and to further,take that function as parameter,a two-way amplitude response intensity change function which is changed with the variable change of azimuth angle is deduced,at the same time,azimuthal orientation oil and gas indicatory factor is deduced.Firstly,the azimuth direction is fixed by the variable resolution method.Then,the amplitude gradient along incidence-angle direction of the azimuth trace set is solved,and then the oil-gas indicator of the azimuth direction is obtained.Using the same method,in other azimuthal the oil and gas indicator factors of all azimuthal directions can be obtained,and then the change of oil and gas indicating sensitivity along azimuthal orientation can be analyzed,and the most sensitive indicating azimuthal orientation of oil and gas can be selected as the final oil and gas prediction result.The application results in the actual survey area show that the prediction results of this method are reliable,which can provide effective support for oil and gas exploration and development.

关 键 词：HTI裂缝介质 全方位角道集 方位振幅梯度 方位油气指示因子 

分 类 号：P631[天文地球—地质矿产勘探]