摘要
采用缩小尺寸的模型井和自制的声波测井模拟试验系统模拟研究正交偶极子声源在井轴与TI介质的对称轴呈不同夹角的模型井中声传播的特征,采用慢度时间相关法、频散分析方法及各向异性分析方法对测量得到的四分量偶极子波形进行分析,并与数值模拟结果进行对比。结果表明:正交偶极子声源在TI介质井孔中激发的弯曲波的速度随井轴与介质对称轴夹角的变化趋势与对应的横波体波速度的变化趋势相一致,且略小于对应的横波体波速度;从试验数据中提取的快、慢弯曲波的频散曲线互相平行,与固有各向异性地层井孔中的快、慢弯曲波频散曲线互相平行的理论相一致;通过HTI井孔中的正交偶极子模拟测量试验验证了地层横波各向异性测量及快横波面测量的可靠性。
By using small-scaled model wells and homemade acoustic logging simulation system, the acoustic field excited by cross-dipole sources was simulated in model wells for different angles between formation symmetry axis and borehole axis. The measured four-component dipole waveforms were analyzed by slowness time coherence method （STC） , slowness disper- sion analysis method and anisotropic analysis method, and were also compared with numerical simulation results. The results show that the variation of the velocity of the flexural wave excited by cross-dipole sources in the borehole surrounded by TI formation is consistent with that of the velocity of corresponding shear body waves, with the changes of the angle between the borehole axis and formation symmetry axis, and is slightly less than that of the corresponding shear body waves. The slowness dispersion curves of the fast and slow flexural waves extracted from experimental data are parallel to each other, which agrees well with the theory that the dispersion curves of flexural waves are parallel to each other in the borehole surrounded by inher-ent anisotropic formation. The reliability of the shear wave anisotropy measurement and the azimuth measurement of the fast shear wave was verified by the cross-dipole acoustic logging simulation experiments in the borehole surrounded by horizontal transverse isotropy （HTI） formation.
出处
《中国石油大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2012年第6期62-69,共8页
Journal of China University of Petroleum(Edition of Natural Science)
基金
国家自然科学基金项目(11204380,11134011,61102102)
国家油气重大科技专项(2011ZX05020-009)
中国石油天然气集团公司项目(2008A-2702、2011A-3903)
关键词
声波测井
正交偶极子声源
TI地层
物理模拟
acoustic well logging
cross-dipole sources
transverse isotropy formation
physical simulation
