基于近地表模型的激发技术研究

发布时间：2018-01-14 23:24

本文关键词：基于近地表模型的激发技术研究　出处：《西南石油大学》2017年硕士论文　论文类型：学位论文

【摘要】：针对复杂地表条件下地震勘探资料信噪比较低的难题,利用波动方程正演技术,研究地震波在近地表的传播特征,应用震源组合理论,探索复杂地区地震激发技术,力求在复杂地区地震资料采集中取得新的进展。炸药震源作为陆地地震勘探的主要激发震源,是决定野外地震资料品质的关键因素。由于近地表结构复杂、岩性变化剧烈、浅表存在异常构造体等因素,在复杂地区野外资料采集过程中,单个震源激发产生的能量并不能均匀辐射,而是受近地表因素的影响产生严重衰减,致使传向目的层的能量大幅下降,地震资料的信噪比也随之降低。因此,常规的单井激发已经无法满足复杂地区高精度地震勘探的需求。为了提高复杂地区地震资料的信噪比,本文在前人的研究基础上,主要做了以下研究工作:1)结合野外地质资料,建立复杂地区的近地表模型,通过黏声波动方程正演模拟,研究基于近地表模型下震源区域能量分布规律,划分震源波场区域;2)定量化分析地层倾角、厚度、岩性、异常构造等近地表因素对震源激发能量的影响;3)对相控震源组合激发主控因素做了详细研究;4)结合常规组合震源与相控震源激发技术,提出了基于近地表模型的组合激发参数优化算法,针对不同的复杂近地表模型对激发井深、激发药量、组内距、震源个数、延迟时间等进行优化设计并得到了最优化组合激发参数。从理论上实现震源激发能量的定向传播,提高了震源下传能量,改善局部资料信噪比,并通过野外实际资料进行验证,取得了良好的应用效果。
[Abstract]:In order to solve the problem of complex surface seismic data under the condition of low SNR, using wave equation modeling technique, the research of seismic wave propagation in the near surface characteristics, application of vibroseis exploration technology of seismic excitation theory, complex area, and strive to make new progress in seismic data acquisition in complex area. As the main source of explosive source land in seismic exploration, is the key factor to determine the quality of field seismic data. Because of the near surface structure of complex lithologic change, superficial abnormal structure and other factors in the complex area of field data acquisition process, a single source generates energy and not uniform radiation, but by the effect of near surface factors have serious attenuation. The spread to the target layer energy decreased significantly decreases the signal-to-noise ratio. Therefore, the conventional single well stimulation has been unable to meet the complex area The need of high precision seismic exploration seismic data in complex area. In order to improve the signal-to-noise ratio, on the basis of previous research, the main research work is done as follows: 1) combining with the geological data, the establishment of the near surface model in complex area, the visco acoustic wave equation forward modeling study on the distribution of regional energy source near surface model based on the classification of source wavefield region; 2) quantitative analysis of dip angle, thickness, lithology, structure and effect of abnormal near surface factors on the source of energy; 3) of PAVS combined excitation of main control factors are studied in detail; 4) combined with the conventional combination of source and PAVS excitation technology optimization algorithm is proposed combining the near surface model based on excitation parameters, aiming at the complex near surface model of different excitation charge on excitation well depth, and group distance, source number, delay time and get the optimized design Optimizing the combined excitation parameters, theoretically realizing the directional propagation of the excitation energy of the source, improving the energy transmission under the source and improving the SNR of the local data, and validating the field data, and achieved good application results.

【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P631.4

【相似文献】