四川盆地西北部深层低幅度构造建模及成像  

Research on modeling and imaging of deep low-amplitude structures in the northwestern Sichuan Basin

作　　者：王艳香[1] 苏勤[1] 乐幸福[1] 张军舵[1] 刘威[1] 袁焕[1] WANG Yanxiang;SU Qin;LE Xingfu;ZHANG Junduo;LIU Wei;YUAN Huan(Research Institute of Petroleum Exploration&Development-Northwest,Petrochina,Lanzhou,Gansu 730020,China)

机构地区：[1]中国石油勘探开发研究院西北分院,甘肃兰州730020

出　　处：《石油地球物理勘探》2021年第1期109-117,I0011,I0012,共11页Oil Geophysical Prospecting

基　　金：中国石油天然气股份公司重大科技专项“西南油气田天然气上产300亿立方米关键技术研究与应用”(2016E-0604)资助。

摘　　要：为落实四川盆地西北部龙门山前带构造圈闭细节,开展了低幅度构造成像、网格层析速度建模和构造物理模拟实验研究。龙门山前带地表地下构造复杂,采用构造正演模拟的方法研究其动力学成因;利用自适应微测井约束初至层析静校正技术解决该区影响低幅度构造成像的静校正问题;应用各向异性动校正技术解决在大炮检距处产生的动校过量问题,提高了浅部陡倾地层及深部低幅度构造的速度分析精度;将约束层析的近地表速度模型和沿层层析获得的中深层速度模型融合,充分利用钻井数据等多信息指导初始速度模型的建立,利用网格层析优化速度模型并偏移,为地震资料解释提供了准确可靠的数据。To disclose the details of structural traps in the Longmenshan piedmont belt in the northwestern Sichuan Basin,we carried out imaging and modeling of deep low-amplitude structures,meshtomography-based velocity modeling,and physical simulations of structures.Longmenshan piedmont belt presents severe surface fluctuations and serious problems of static correction.Then adaptive first-arrival tomographic inversion with micro-logging constraints is adopted to solve the problem of static correction that affects the imaging of lowamplitude structures.Besides,excessive dynamic calibration is avoided by anisotropic dynamic correction at large offsets,improving the accuracy of velocity analysis in shallow and steeply-dipping strata and deep low-amplitude structures.Moreover,the near-surface velocity model of constrained tomography and the mid-deep velocity model obtained by layered tomography are combined to guide the construction of an initial velocity model based on full use of well-logging data.Mesh tomography is used to optimize the velocity model and perform pre-stack depth migration.Therefore,seismic interpretation is supported by accurate and reliable data.

关 键 词：四川盆地西北部 深部低幅度构造 自适应微测井约束层析静校正 层控网格层析 构造物理模拟 

分 类 号：P631[天文地球—地质矿产勘探]