【作者】 陈枫；

【导师】 段云卿；

【作者基本信息】 中国地质大学（北京） ， 地球探测与信息技术， 2011， 硕士

【摘要】 地震勘探是重要的地球物理方法之一,尤其在油气勘探中,地震勘探是目前最主要的方法。随着油气资源的开采,勘探难度也逐渐增大,精细化处理解释更是当前的要求。在地震资料处理中,偏移成像技术是早些年已经发展起来的技术,偏移算法的不断完善、精确,使得地下成像归位更接近真实构造。可是,复杂的偏移计算一直是与计算效率相矛盾的,如果想提高成像质量,是要以牺牲大量的计算时间为代价的。本文研究了GPU叠前时间偏移的方法及应用,它是针对偏移算法的精确化和偏移效率的提高而实现的。所研究的GPU叠前时间偏移采用目前常用的克希霍夫积分偏移方法。主要进行了以下几个方面的工作:(1)推导了一种弯曲射线走时的克希霍夫叠前时间偏移的算法。由于克希霍夫积分偏移的精确性主要取决于地震波走时的计算,因此根据假设近似条件,地震波在VTI介质中以弯曲射线的形式传播,将精确计算时距方程高阶项得到的走时代入波动方程克希霍夫积分解中,来进行偏移处理。(2)推导出保幅克希霍夫积分偏移的保幅因子。根据振幅随入射角的衰减特性,推导了振幅补偿因子,对振幅进行补偿,以达到保幅处理的目的。(3)简要讨论了各向异性校正,它使复杂构造地区的成像更精确。(4)引入GPU技术以解决偏移计算效率问题。伴随着偏移算法的精确,其复杂性和计算量也成倍增长,为了解决计算效率的问题,引入GPU技术。(5)用实际资料的动力学特征和时间切片对比说明GPU偏移的结果是同CPU偏移的结果一样可靠的。(6)研究GPU叠前时间偏移的技术特色及效果分析。按照GPU叠前时间偏移的步骤,逐步分析该偏移方法的技术特色,研究其对偏移结果的影响,通过举例分析,得到偏移的效果及与其他偏移效果的对比分析。(7)应用实际地震资料处理。通过实际地震资料处理和对比分析,说明基于GPU技术的叠前时间偏移的效果和效率,并说明这种偏移方法完全适用于实际应用。基于GPU技术的叠前时间偏移研究是一项侧重于应用的技术,目前,叠前时间偏移已经是常规的处理流程,因此,更精确的偏移方法,更省时的偏移效率对于地震数据处理流程更显重要。研究表明,本文所采用的技术和研究方法是切实可行的,在效果和效率上也能取得令人满意的结果。更多还原

【Abstract】 Seismic exploration is one of the most important geophysical methods. Respecting to oil prospecting, seismic exploration is the main method. It consists of acquisition, processing, and interpretation. These flows are connected because the results of the former flow are the inputting data for the next. It is harder for exploration with the exploitation of oil. The requirement of accuracy of processing and interpretation is higher. In the flow of processing data, migration is the technique developed many years ago. With the development of arithmetic of migration, the imaging of subsurface could be described as real formation. However, the contradiction between accuracy and efficiency of migration is always there. The quality of imaging can be improved sacrificing a lot of time for calculation.In this paper, it discussed a new technology, GPU pre-stack migration and its application. It can solve the difficulties of quality and efficiency. GPU pre-stack migration used normally Kirchhoff integral migration method. Works done are as follows: (1) It discussed arithmetic of ray-bending pre-stack Kirchhoff migration. This was an arithmetic that the wave spread from the VTI medium in ray-bending. It was calculated by results of Kirchhoff integral of wave equation, replacing the travel time by the result of time-offset equation in high order. (2)It deduced the factor of amplitude preservation. According to the amplitude variation with incidence, it compensated the amplitude in order to preserve it. In the calculation of this arithmetic, it used anisotropy correction to image the accurate formation. (3)It discussed the anisotropy correction in brief. The correction made out precise migration results. (4) GPU technology could improve the efficient. With the improvement of migration’s arithmetic, the problems of complex calculation came out. In order to solve this problem, in this paper, it brought in GPU technique. (5) It used real seismic data processing to prove the dependability of GPU method. (6) Studied the characteristics and results’analysis of GPU pre-stack migration. It analyzed the advantages of this method step by step, studying the consequence to the results. (7) It discussed the application in real seismic data processing. It would compare the new processing data to the old ones in order to illustrate the results and improvement of GPU based pre-stack time migration.GPU pre-stack migration is a method which is good for practice. In this time, pre-stack migration is normal flow. Therefore, precise migration method and high efficient are important to processing. The technique discussing in this paper is reliable.更多还原