射线域弹性阻抗反演在阿姆河右岸碳酸盐岩气藏储层预测中的应用  

Application of ray-path elastic impedance inversion in carbonate gas reservoir prediction of the right bank of Amu Darya River

作　　者：张天择 王红军[1] 张良杰[1] 张文起[1] 谢明贤 雷明[2] 郭强 张雪锐 ZHANG Tianze;WANG Hongjun;ZHANG Liangjie;ZHANGWenqi;XIE Mingxian;LEI Ming;GUO Qiang;ZHANG Xuerui(Research Institute of Petroleum Exploration&Development,PetroChina,Beijing 100083,China;Research Institute of Petroleum Exploration and Development-Northwest,PetroChina,Lanzhou 730020,China;Research Institute of Exploration and Development,PetroChina Yumen Oilfield Company,Jiuquan 735019,Gansu,China)

机构地区：[1]中国石油勘探开发研究院,北京100083 [2]中国石油勘探开发研究院西北分院,兰州730020 [3]中国石油玉门油田公司勘探开发研究院,甘肃酒泉735019

出　　处：《岩性油气藏》2024年第6期56-65,共10页Lithologic Reservoirs

基　　金：中国石油天然气集团有限公司专项“复杂碳酸盐岩气藏持续稳产关键技术研究——复杂碳酸盐岩气藏持续稳产关键技术研究”(编号:2021DJ3301);四川省自然科学基金项目“二氧化碳在页岩气储层内长期封存对页岩封闭性能影响的实验及机理研究”(编号:2022NSFSC0187)联合资助。

摘　　要：阿姆河右岸阿盖雷气田中上侏罗统卡洛夫—牛津阶碳酸盐岩储层勘探难度大、地震反射能量弱、地震资料信噪比低。以储层特征及岩石物理分析为基础,通过叠前道集优化处理、井-震联合低频阻抗建模以及叠前射线域弹性阻抗反演方法,对该地区含气储层进行了预测。研究结果表明:①阿盖雷气田中上侏罗统卡洛夫—牛津阶储层主要为台地前缘缓坡相碳酸盐岩,岩性主要为砂屑灰岩和生屑灰岩,储集空间以孔隙-裂缝型为主,具有低孔、低渗和非均质性强的特征;有效含气储层主要表现为低纵波阻抗、低剪切模量、低体积模量特征,剪切模量对含气储层的敏感程度最高。②通过预测剔除去噪,奇异值分解去噪和谱平衡能量补偿手段对叠前道集进行处理可以有效去除异常振幅等高频及随机噪音,提升有效信号强度并增强远偏移距AVO特征;井-震联合建模方法通过引入低频层速度解决因地震数据低频信息缺失而造成的反演多解性问题,提高了反演精度的同时有效表征了储层横向变化;叠前射线域弹性阻抗反演方法在研究区应用效果好,纵、横波阻抗反演体在纵、横向上均表现出较高的分辨能力,预测的含气储层厚度与测井解释的成果吻合度达85%以上,反演体显示气层的横向连续性较差,符合缓坡滩沉积特征。③研究区碳酸盐岩储层具有良好的勘探开发潜力,东部和西南部的未钻区域有多处明显的含气显示;上部Gap—XVhp段含气显示更好。The reflection energy of middle-upper Jurassic Karlov-Oxfordian carbonate reservoir in the Agayry gas field on the right bank of the Amu Darya River is weak,and the signal-to-noise ratio of seismic data is low.Based on the analysis of reservoir characteristics and rock physics,the gas-bearing reservoir is predicted by prestack gather conditioning,well-seismic joint low-frequency impedance modeling,pre-stack ray domain elastic impedance inversion.The results show that:(1)The Calllovian-Oxfordian reservoirs in the middle and upper Jurassic of the Agayry gas field are mainly gentle slope carbonate rocks in the front edge of the platform.The lithology is mainly sandy limestone and bioclastic limestone.The reservoir space is dominated by pore-fracture type,which has the characteristics of low porosity,low permeability and strong heterogeneity.The results of rock physics analysis show that the effective gas-bearing reservoirs are mainly characterized by low longitudinal wave impedance,low shear modulus and low bulk modulus,and the shear modulus is the most sensitive to gasbearing reservoirs.(2)The pre-stack gathers are processed by means of prediction elimination denoising,singular value decomposition denoising and spectral balance energy compensation,which can effectively remove highfrequency and random noise such as abnormal amplitude,improve the effective signal strength and enhance the AVO characteristics at far offset.The well-seismic joint modeling method solves the problem of multi-solution inversion caused by the lack of low-frequency information of seismic data by introducing low-frequency layer velocity,which improves the inversion accuracy and effectively characterizes the lateral change of reservoir.The pre-stack ray domain elastic impedance inversion method has a good application effect in the study area.The P-wave and S-wave impedance inversion results show high resolution in both vertical and horizontal directions.The predicted gas-bearing reservoir thickness is more than 85%consistent with the results o

关 键 词：射线域弹性阻抗反演 碳酸盐岩储层 叠前道集优化 井-震联合 岩石物理分析 Gap—XVhp 卡洛夫—牛津阶 侏罗系 阿盖雷气田 阿姆河右岸 

分 类 号：P631.4[天文地球—地质矿产勘探] P618.13[天文地球—地质学]