丘东气田西山窑组波形指示反演砂体识别  

Sand body identification by waveform indication inversion in Xishanyao Formation of Qiudong Gas Field

作　　者：谢锐杰[1,2] 曹永强 李瑶 唐欢欢[1,2] XIE Ruijie;CAO Yongqiang;LI Yao;TANG Huanhuan(School of Geophysics and Petroleum Resources,Yangtze University,Wuhan 430100,Hubei;Key Laboratory of Exploration Technologies for Oil and Gas Resources,Ministry of Education(Yangtze University),Wuhan 430100,Hubei)

机构地区：[1]长江大学地球物理与石油资源学院,湖北武汉430100 [2]油气资源与勘探技术教育部重点实验室(长江大学),湖北武汉430100

出　　处：《长江大学学报（自然科学版）》2023年第2期29-36,共8页Journal of Yangtze University(Natural Science Edition)

基　　金：国家科技重大专项“川西源内成藏体系成藏机理研究”(2016ZX05002-004-009)。

摘　　要：丘东气田西山窑组发育一套以扇三角洲前缘为主的灰色砂岩,其是主要的含气层段。为了查明砂体的分布规律,通过测井曲线敏感性分析发现:有效砂岩主要集中在高波阻抗区域,非储层主要集中在低波阻抗区域,可以明显区分砂泥岩,分界线在8000(g·m)/(s·cm^(3));深侧向电阻率RLLD曲线相较于自然伽马、自然电位等测井曲线,对岩性的识别敏感度较大,因此选用RLLD曲线重构进行波形指示反演。在平滑半径、有效样本数、频率参数等反演参数对比分析的基础上,对重构后的波阻抗曲线开展反演工作。反演结果表明,垂向上对较薄砂体的识别能力大大增强,反演精度较高,可以刻画出厚度5 m左右的单砂体;砂体分布从南往北逐渐减薄,东北部砂岩不发育,物源主要来自南部。经后期钻探验证,该方法有效增强了对砂岩的识别能力,缩小了岩性气藏的勘探范围,提高了钻探成功率。The Xishanyao Formation of Qiudong Gas Field develops a set of grey sandstones dominated by the front of fan delta,which is the main gas-bearing interval.In order to find out the distribution law of sand bodies,through the sensitivity analysis of logging curves,it is found that the effective sandstone is mainly concentrated in the high wave impedance area,and the non-reservoir is mainly concentrated in the low wave impedance area,which can clearly distinguish sand and mudstone with the boundary at 8000(g·m)/(s·cm^(3)).Compared with logging curves such as natural gamma and spontaneous potential,the deep lateral resistivity curve RLLD has a greater sensitivity to lithology identification.Therefore,RLLD curve reconstruction was selected for waveform indication inversion.On the basis of the comparative analysis of inversion parameters such as smooth radius,valid sample number and frequency parameters,the inversion work was carried out on the reconstructed wave impedance curves.The inversion results show that the ability to identify thinner sand bodies in the vertical direction is greatly enhanced,the inversion accuracy is high,and the single sand body with a thickness of about 5 m can be described;The sand body distribution gradually decreases from south to north,the sandstone in the northeast is not developed,and the provenance mainly comes from the south.After later drilling verification,this method effectively enhances the ability to identify sandstone,narrows the exploration scope of lithologic gas reservoirs,and improves the drilling success rate.

关 键 词：波形指示反演 砂体识别 丘东气田 西山窑组 

分 类 号：P631.44[天文地球—地质矿产勘探]