【作者】 宋海燕；

【导师】 宋建国；

【作者基本信息】 中国石油大学 ， 地球探测与信息技术， 2009， 硕士

【摘要】 当今勘探和开发工作面临的挑战需要高精度?高清晰度和高可信度的技术,井孔地震的研究日益受到广泛的应用,尽管目前无论垂直地震剖面(Vertical Seimic Profile,简称VSP)还是井间地震的成本较其他技术来说是比较高的?从复杂的井孔地震记录中提取纵横波场,进行有效波成像日益关键?本文针对井间三分量采集数据,研究纵横波分离方法,提取纵横波分量,进而研究反射波波动方程成像方法?根据高分辨率Radon变换基本原理,针对井孔地震采样率高?频带宽?主频高?道间距小等特点,对高分辨率Radon正反变换方法进行了研究,编制了相关程序,调试参数使收敛效果最佳?根据井中三分量接收系统的独特性,结合纵波和横波在不同分量上的极性特性,在Radon域用极化滤波对纵横波进行分离,并编程现实?对理论模型和实际数据进行处理,成功分离了纵横波波场?然后对提取的纵横波波场,进行井间波动方程有限差分偏移成像?从波动方程偏移基本原理出发,结合井间地震的特点,对井间剖面进行网格划分,利用射线追踪方法求取成像时间,利用有限差分方法对井间波场进行延拓,并应用成像条件,实现了有限差分逆时偏移算法?模型和实际资料处理结果表明纵横波波场成像能够真实地反应地层产状,且其成像结果具有较高的分辨率和信噪比?通过对比发现,横波成像结果要比纵波成像结果好,更充分地利用了井中的地震波场信息?更多还原

【Abstract】 Nowdays the challenge of seismic E&D needs the techniques of high accuracy,high definition,high confidence;this gives rise to quick development of borehole seismic technique,though at present the cost of no matter VSP or crosswell is higher.How to get P/S wave from complex borehole seismic record and crosswell seismic imaging are hot research point of crosswell seismic data processing.Based on the acquisition of 3C borehole seismic, we research the separation of P and S waves, extract P and S wave component, and study wave equation imaging methods. Depending on principle of high resolution frequency domain radon transform, according to the characters of crosswell data such as: high sample rate, wide spectrum, high main frequency quantity, we research high resolution radon transform; corresponding processing program are developed and various parameters are tested and adjusted. Considering the specific feature of 3C borehole seismic acquisition system and the difference of P and S wave in polar nature, we utilize high resolution forward/inverse radon transform to develop the P/S wavefield separation method in ? ?pdomain, and design corresponding program.Processing of simulated data of theoretical model and practical crosswell model separates P/S wavefield successfully. In the basis of extracting P and S wavefield, depending on data structure of existing crosswell seismic processing system, we transplant wave equation finite-difference migration method into crosswell seismic data processing. Considering the character of crosswell seismic, we grid the crosswell section, calculate imaging time by ray-tracing, use finite-difference method to achieve crosswell wavefield reverse time continuation, and finally apply imaging condition to get finite-difference reverse-time migration profile. Processing results implies that imaging from extracted P/S wavefiled can reflect actual attitude of strata actually, and the imaging results have high resolution and high S/N.更多还原