【作者】 张丰麒；

【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， 2011， 硕士

【摘要】 由于岩性油气藏勘探的需要,因此利用更加精确的弹性参数进行储层预测和流体识别的工作势在必行。而多波多分量地震勘探的兴起,转换波资料的静校正、偏移成像等技术的日益成熟,为开展联合纵波和转换波反演打下坚实的基础。由于转换波资料的加入,降低了反演矩阵的条件数和奇异性,从而提高了反演的精度,特别是横波速度反演的精度。本论文所研究的反演方法是基于广义线性反演的叠前AVA反演,利用叠前时间偏移提供的纵波和转换波的角度域成像点道集作为反演输入的地震道集,利用偏移速度分析提供的纵波和转换波的均方根速度作为反演的初始模型,以井资料作为约束,从精确的zoeppritz方程出发,通过正演模拟迭代的方法,进行叠前AVA三参数同时反演,反演参数包括纵波速度、横波速度和密度。而影响多波AVA反演精度的一个最主要因素是纵波和转换波资料的匹配问题,该问题也一直是多波多分量地震勘探中的一个难点。本论文通过总结前人的方法,提出了利用纵波均方根速度和转换波均方根速度之间的相互关系来提取出平均纵横波速度比的方法来计算将转换波旅行时压缩到纵波旅行时的校正系数,从而完成了叠前纵波和转换波角道集的匹配。同时该论文还依次讨论了叠前道集的相位校正,AVA真振幅恢复和部分叠加对反演结果的影响。单一纵波反演的横波速度估计是不准确的;单一转换波反演的纵波速度估计是不准确的;联立纵波、转换波反演可以同时得到准确的纵波速度和横波速度估计。更多还原

【Abstract】 Because of the need of the prospection of the lithologicalpool,it is imperative to implement reservoir prediction and fluid discrimination by the elasticparameter precisely inverted.The 3D-3C seismic prospecting has sprung up ,and the technology of the statics correction and the migration of the converted wave has been increasingly perfect,which contribute to promote the development of the simultaneous inversion by P-P and P-S wave.Because of the add of the converted wave,the conditional number and singularity of the matrix for inversion is decreased,and the precision of the inversion is improved,especially in the evaluation of the precision of the velocity of the shear wave.The inversion researched by this thesis is prestack AVA inversion based on the methodology of generalized linear inversion.By using the ADCIP provided by the prestack time migration as the input gather for inversion ,the RMS velocities of P-P and P-S wave via the velocity analysis of migration as the initial model for inversion and the log information as the restraint for the inversion,the prestack AVA inversion for three parameters including P wave velocity,S wave velocity and density is proformed via the precise Zoeppritz function by the idea of forward modeling interation.The problem of the matching of P-P and P-S data also as a difficult point in the exploration of 3D-3C seismic is the main factor affecting the precision of the inversion.This thesis presents a methodology of extraction of the average ratio of P-wave to S-wave velocity which is used to compute the scaler for mapping P-S time to P-P time by using the relation between the P-wave RMS velocity and the P-S wave RMS velocity.This thesis also reseaches the influence of the phase correction,AVA true amplitude recovery and partial stack in prestack gathers to the precision of the inversion. The inversion by only P-P wave data often can get a better evaluation of the P-wave velocity and density than of the S-wave velocity,while the inversion by only P-S wave data can often get a better evaluation of the S-wave velocity and density than of the P-wave velocity.So the simultaneous inversion by P-P and P-S data can get a good evaluation of these three parameters at the same time.更多还原