井外爆炸点源激发井孔声波场
|
摘要
利用井外爆炸点源激发的声波场与井孔的相互作用模拟井间地震的物理过程,推导了全频域井孔内外声波场的理论计算公式,并针对不同震源主频、不同源距(震源到井轴的径向距离)和软硬地层进行了井内声场的全波模拟与频率-相速度分析。结果表明:井外爆炸点源激发井孔内外的声场等效于无穷多级声场迭加的结果;震源靠近井壁时的频率-相速度图与震源在井内时相似;震源的主频越高、源距和接收器离井轴的径向距离越大、地层越硬,则顾及的多级声场的项数就要越多;震源主频越低、源距越小,井中激发的斯通利波则越强。
A physics model for cross well seismic based on interaction between acoustic field excited by an external explosive source and a borehole has studied.The theoretical expressions of acoustics for all frequency in and out a borehole are obtained.Full waveform simulation and frequency-phase velocity analysis for different center frequency of seismic source,different offset and different formation were studied.The results show that the acoustic fields inside the borehole are composed of infinitude of multiple fields with different orders.It shows the frequency-velocity figures for source nearby borehole wall are similar to those of acoustic logs.The higher center frequency,more formation hardy and more different offset,the more orders should be calculated.The amplitude of Stoneley waves will increase as center frequency and offset are becoming smaller.It is of help us to further understand cross well seismic prospecting by theoretical and numerical simulation.
A physics model for cross well seismic based on interaction between acoustic field excited by an external explosive source and a borehole has studied.The theoretical expressions of acoustics for all frequency in and out a borehole are obtained.Full waveform simulation and frequency-phase velocity analysis for different center frequency of seismic source,different offset and different formation were studied.The results show that the acoustic fields inside the borehole are composed of infinitude of multiple fields with different orders.It shows the frequency-velocity figures for source nearby borehole wall are similar to those of acoustic logs.The higher center frequency,more formation hardy and more different offset,the more orders should be calculated.The amplitude of Stoneley waves will increase as center frequency and offset are becoming smaller.It is of help us to further understand cross well seismic prospecting by theoretical and numerical simulation.
引文
[1]Lee M W.Partical displacements on the wall of aborehole from incident plane wave[J].Geophysics,1987,52(9):1290-1296.
[2]王克协,White J E,伍先运.Biot介质中P波与井孔的耦合[J].地球物理学报,1996,36(1):103-112.WANG Ke-xie,White J E,WU Xian-yun.P-wavecouple to hole in Biot solid[J].Chinese Journal ofGeophysics,1996,36(1):103-112.
[3]Qiu C C,Zhang B X,Zhang Y J,et al.Coupling ofacoustical plane P-wave to a cased borehole[J].Chinese Physics Letter,2009,26(11):4301-4304.
[4]Ionov A M,Maximov G A.Excitation of a tube wavein a borehole by an external seismic source[J].Acoustical Physics,1999,45(3):311-316.
[5]Bokov P M,Ionov A M.Excitation of a tube wave in aborehole by an external isotropic point source[J].Acoustical Physics,2001,47(6):654-658.
[6]Kurkjian A L,Cheng S K.Acoustic multipole sourcesin fluid-filled borehole[J].Geophysics,1986,51(1):148-163.
[7]Abramowitz M,Stegun I A.Handbook of mathema-tical functions with formulas,graphs,andmathematical tables[M].New York:DoverPublications Inc,1972.
[8]周来江.井外声源激发井孔声场及井间地震的理论研究与数值模拟[D].长春:吉林大学,2006.ZHOU Lai-jiang.Theoretical and numerical study ofborehole acoustic field excited by external acousticsources and cross well seismic[D].Changchun:JilinUniversity,2006.
[9]Schmitt D P,Bouchon M.Full-wave acoustic logging:synthetic microseismograms and frequency-wavenumber analysis[J].Geophysics,1985,50(11):1756-1778.
[10]岳崇旺,王祝文,陈博涛,等.井孔声场二维谱的数值计算与理论分析[J].吉林大学学报:地球科学版,2009,39(3):535-540.YUE Chong-wang,WANG Zhu-wen,CHEN Bo-tao,et al.Numerical calculation and analysis on two-dimensional spectrum for acoustic wave propagationin a borehole[J].Journal of Jilin Unviersity:EarthScience Edition,2009,39(3):535-540.
[2]王克协,White J E,伍先运.Biot介质中P波与井孔的耦合[J].地球物理学报,1996,36(1):103-112.WANG Ke-xie,White J E,WU Xian-yun.P-wavecouple to hole in Biot solid[J].Chinese Journal ofGeophysics,1996,36(1):103-112.
[3]Qiu C C,Zhang B X,Zhang Y J,et al.Coupling ofacoustical plane P-wave to a cased borehole[J].Chinese Physics Letter,2009,26(11):4301-4304.
[4]Ionov A M,Maximov G A.Excitation of a tube wavein a borehole by an external seismic source[J].Acoustical Physics,1999,45(3):311-316.
[5]Bokov P M,Ionov A M.Excitation of a tube wave in aborehole by an external isotropic point source[J].Acoustical Physics,2001,47(6):654-658.
[6]Kurkjian A L,Cheng S K.Acoustic multipole sourcesin fluid-filled borehole[J].Geophysics,1986,51(1):148-163.
[7]Abramowitz M,Stegun I A.Handbook of mathema-tical functions with formulas,graphs,andmathematical tables[M].New York:DoverPublications Inc,1972.
[8]周来江.井外声源激发井孔声场及井间地震的理论研究与数值模拟[D].长春:吉林大学,2006.ZHOU Lai-jiang.Theoretical and numerical study ofborehole acoustic field excited by external acousticsources and cross well seismic[D].Changchun:JilinUniversity,2006.
[9]Schmitt D P,Bouchon M.Full-wave acoustic logging:synthetic microseismograms and frequency-wavenumber analysis[J].Geophysics,1985,50(11):1756-1778.
[10]岳崇旺,王祝文,陈博涛,等.井孔声场二维谱的数值计算与理论分析[J].吉林大学学报:地球科学版,2009,39(3):535-540.YUE Chong-wang,WANG Zhu-wen,CHEN Bo-tao,et al.Numerical calculation and analysis on two-dimensional spectrum for acoustic wave propagationin a borehole[J].Journal of Jilin Unviersity:EarthScience Edition,2009,39(3):535-540.
版权所有：© 2023 中国地质图书馆 中国地质调查局地学文献中心