中国物理B ›› 2016, Vol. 25 ›› Issue (12): 124316-124316.doi: 10.1088/1674-1056/25/12/124316

• SPECIAL TOPIC—Acoustics • 上一篇    下一篇

Generalized collar waves in acoustic logging while drilling

Xiu-Ming Wang(王秀明), Xiao He(何晓), Xiu-Mei Zhang(张秀梅)   

  1. State Key Laboratory of Acoustics, Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190, China
  • 收稿日期:2016-08-16 修回日期:2016-10-20 出版日期:2016-12-05 发布日期:2016-12-05
  • 通讯作者: Xiao He E-mail:hex@mail.ioa.ac.cn
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant Nos. 11134011 and 11374322) and the Foresight Research Project, Institute of Acoustics, Chinese Academy of Sciences.

Generalized collar waves in acoustic logging while drilling

Xiu-Ming Wang(王秀明), Xiao He(何晓), Xiu-Mei Zhang(张秀梅)   

  1. State Key Laboratory of Acoustics, Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190, China
  • Received:2016-08-16 Revised:2016-10-20 Online:2016-12-05 Published:2016-12-05
  • Contact: Xiao He E-mail:hex@mail.ioa.ac.cn
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant Nos. 11134011 and 11374322) and the Foresight Research Project, Institute of Acoustics, Chinese Academy of Sciences.

摘要:

Tool waves, also named collar waves, propagating along the drill collars in acoustic logging while drilling (ALWD), strongly interfere with the needed P- and S-waves of a penetrated formation, which is a key issue in picking up formation P- and S-wave velocities. Previous studies on physical insulation for the collar waves designed on the collar between the source and the receiver sections did not bring to a satisfactory solution. In this paper, we investigate the propagation features of collar waves in different models. It is confirmed that there exists an indirect collar wave in the synthetic full waves due to the coupling between the drill collar and the borehole, even there is a perfect isolator between the source and the receiver. The direct collar waves propagating all along the tool and the indirect ones produced by echoes from the borehole wall are summarized as the generalized collar waves. Further analyses show that the indirect collar waves could be relatively strong in the full wave data. This is why the collar waves cannot be eliminated with satisfactory effect in many cases by designing the physical isolators carved on the tool.

关键词: acoustic logging while drilling, borehole wave propagation, generalized collar waves, indirect collar waves

Abstract:

Tool waves, also named collar waves, propagating along the drill collars in acoustic logging while drilling (ALWD), strongly interfere with the needed P- and S-waves of a penetrated formation, which is a key issue in picking up formation P- and S-wave velocities. Previous studies on physical insulation for the collar waves designed on the collar between the source and the receiver sections did not bring to a satisfactory solution. In this paper, we investigate the propagation features of collar waves in different models. It is confirmed that there exists an indirect collar wave in the synthetic full waves due to the coupling between the drill collar and the borehole, even there is a perfect isolator between the source and the receiver. The direct collar waves propagating all along the tool and the indirect ones produced by echoes from the borehole wall are summarized as the generalized collar waves. Further analyses show that the indirect collar waves could be relatively strong in the full wave data. This is why the collar waves cannot be eliminated with satisfactory effect in many cases by designing the physical isolators carved on the tool.

Key words: acoustic logging while drilling, borehole wave propagation, generalized collar waves, indirect collar waves

中图分类号:  (General linear acoustics)

  • 43.20.+g
43.35.+d (Ultrasonics, quantum acoustics, and physical effects of sound) 43.58.+z (Acoustical measurements and instrumentation) 43.60.+d (Acoustic signal processing)