地球物理学进展 ›› 2018, Vol. 33 ›› Issue (6): 2310-2317.doi: 10.6038/pg2018CC0044

• 应用地球物理学Ⅰ(油气及金属矿产地球物理勘探) • 上一篇    下一篇

结合稳相的高效黏弹性叠前时间偏移方法及应用

初海红   

  1. 大庆油田有限责任公司勘探开发研究院,黑龙江大庆 163712
  • 收稿日期:2018-03-30 修回日期:2018-09-16 出版日期:2018-12-20 发布日期:2019-03-03
  • 作者简介:初海红,女,1984年生,硕士,工程师,从事多波地震处理、高分辨率处理、复杂构造成像及粘弹性介质偏移研究.(E-mail: chuhaihong@perochina.com.cn)
  • 基金资助:
    中国石油天然气股份有限公司重大科技专题项目资助(2011E-1217)

Highly effective viscous elasticstationary-phase pre-stack time migration and its application

CHU Hai-hong   

  1. Exploration and Development Institute of Daqing Oilfield LLC, Heilongjiang Daqing 163712, China
  • Received:2018-03-30 Revised:2018-09-16 Online:2018-12-20 Published:2019-03-03

摘要:

地震分辨率是制约油气勘探开发和油藏描述的瓶颈技术.地震波在黏弹性介质传播过程中,由介质的吸收效应引起的地震波能量衰减与子波频散现象严重,极大的降低了地震资料的分辨率.黏弹性稳相叠前时间偏移实现了在稳相偏移成像过程中补偿传播介质引起的吸收,恢复高频成分的衰减,从而使偏移成像结果具有更高分辨率及成像精度.文中首先介绍了黏弹性叠前时间偏移成像方法,在考虑高频噪声放大问题上引入基于稳相原理的偏移孔径求取,压制偏移噪声,同时给出了修正的偏移走时计算方法,提高了对陡倾角构造和断层的成像精度.针对偏移计算耗时问题,采用分时的频率域成像算法,大幅提升了偏移计算效率.多个三维地震工区实际资料的应用效果表明该方法具有展宽频带、压制高频噪声、计算效率和成像精度高的优势.与常规处理成果相比,能够在保持低频成分的同时展宽频带15 Hz以上.

关键词: 黏弹性介质, 吸收, 频散, 叠前稳相偏移, 等效Q值, 分辨率

Abstract:

Seismic resolution is a bottleneck technology that restricts oil and gas exploration and development at reservoir description. The seismic wave energy attenuation and the wavelet dispersion caused by the absorption effect of the seismic wave in the viscoelastic medium are serious, which greatly reduces the resolution of the seismic data. Viscous elastic stationary-phase pre-stack time migration can compensate absorption and dispersion via an actual wave propagation path using effective Q parameter. We can obtain a much higher resolution imaging accuracy. In this paper, the viscous elastic pre-stack time migration method is introduced, and the aperture based on the stationary-phase principle is introduced to consider the high-frequency noise problem. Then we modified the travel calculation method, it can improve the ability to image steep dip structure and fault. Because the viscous elastic pre-stack time migration is implemented in frequency domain, the computation amount is much higher than the conventional PSTM, we improved the efficiency by splitting one seismic trace into several segments in time domain which can greatly improves computation efficiency. We applied the method in the actual 3D seismic data processing, it showed the method has the advantages of broadening the band, suppressing high frequency noise, calculation efficiency and imaging precision. Comparing with regular result, it can wide the frequency band by 15 Hz or more while maintaining the low frequency component.

Key words: viscous elastic media, absorption, dispersion, stationary-phase migration, effective Q, resolution

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