石油学报 ›› 2016, Vol. 37 ›› Issue (9): 1152-1158,1178.DOI: 10.7623/syxb201609009

• 地质勘探 • 上一篇    下一篇

随钻偶极横波远探测优势频带及反射声场

谭宝海, 唐晓明, 魏周拓, 曹景记, 苏远大   

  1. 中国石油大学地球科学与技术学院COSL-UPC声学测井联合实验室 山东青岛 266580
  • 收稿日期:2015-07-26 修回日期:2016-06-28 出版日期:2016-09-25 发布日期:2016-09-30
  • 通讯作者: 唐晓明,男,1955年11月生,1982年获北京大学学士学位,1990年获麻省理工学院地球物理专业博士学位,现为中国石油大学(华东)教授,主要从事声波测井理论方法与应用研究工作。Email:tangxiam@aliyun.com
  • 作者简介:谭宝海,男,1978年4月生,2001年获石油大学(华东)学士学位,2004年获中国石油大学(华东)地球探测与信息技术专业硕士学位,现为中国石油大学(华东)讲师,主要从事随钻声波测井理论及仪器方面的研究工作。Email:tanbaohai@upc.edu.cn
  • 基金资助:

    国家重点基础研究发展计划(973)项目(2014CB239006)、国家自然科学基金项目(No.41404091)、山东省自然科学基金项目(ZR2014DQ004)和青岛 市应用基础研究计划项目(15-9-1-63-jch)资助。

Dominant frequency band and reflected wave field of LWD dipole shear wave remote detection

Tan Baohai, Tang Xiaoming, Wei Zhoutuo, Cao Jingji, Su Yuanda   

  1. School of Geosciences, China University of Petroleum, COSL-UPC Allied Borehole Acoustic Laboratory, Shandong Qingdao 266580, China
  • Received:2015-07-26 Revised:2016-06-28 Online:2016-09-25 Published:2016-09-30

摘要:

电缆声波远探测测井已取得了长足进展,将这种技术应用于随钻声波测井,特别是随钻地质导向方面,具有潜在的应用价值。针对偶极声源随钻反射声波成像测井,基于偶极声源在井外无限大地层中产生的SH横波和SV横波的位移远场渐近解,对比分析了有无钻铤时井外地层辐射声场及井内声场,以及相应的偶极声场激发频带;结合三维有限差分数值模拟方法,讨论了井旁存在声阻抗不连续面时,井内接收的随钻偶极全波波形的SH反射横波变化特征。分析表明:与裸眼情况下相比,随钻条件下的SH和SV横波辐射指向性除受钻井井孔的调制外,同时还受到钻铤的强烈调制。尽管如此,随钻偶极横波同样适用于远探测成像测井,其中偶极声源存在一个优势激发频带,在仪器设计上应考虑和利用。

关键词: 随钻偶极, 声波远探测, 辐射声场, 反射声场, 优势频带

Abstract:

Great progresses have been made in cable acoustic remote detection logging. This technology has a potential application value for acoustic logging-while-drilling (LWD), especially for LWD geo-steering. Aiming at the dipole-acoustic-source reflection acoustic imaging logging while drilling, based on the asymptotic far-field solution for displacement of SH and SV shear waves generated by dipole acoustic source in outside-borehole infinite formation, a comparative analysis was performed on the radiated acoustic field in outside-borehole formation and borehole acoustic field with or without drill collar as well as the corresponding dipole-acoustic-field excitation frequency band. In combination with 3D finite difference numerical simulation method, the variation characteristics of the reflected SH shear waves with LWD dipole full waveforms received in the borehole were discussed in case of acoustic impedance discontinuity on borehole side. The analysis results show that compared with open hole, the SH and SV shear wave radiation directivity is not only modulated by drill borehole, but also strongly modulated by drill collar under LWD conditions. Nevertheless, LWD dipole shear wave can be also used in remote detection imaging logging, and a dominant excitation frequency band exists in dipole acoustic source, which should be considered and applied in apparatus design.

Key words: LWD dipole, acoustic remote detection, radiation wave field, reflected wave field, dominant frequency band

中图分类号: