枪口节流作用和热传导作用对海上勘探气枪子波的影响
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摘要
海上地震勘探多使用气枪震源进行激发,气枪子波的研究对于海上地震采集和资料处理具有十分重要的意义。枪口的节流作用和热传导作用影响着气枪子波的特性。为此,基于自由气泡理论,考虑气枪机械因素以及气泡周围环境的影响,建立了气枪震源子波数值模型。利用该模型就枪口节流作用和气泡壁的热传导作用对气枪子波的影响进行了分析。结果表明:枪口节流作用与气枪枪口面积有关,影响气枪内高压气体的释放速度,进而削减气枪子波的主脉冲;气泡振动加快了气泡周围流体的运动速度,气泡壁的热传导作用随之加强,气泡损失更多的能量,气泡振动衰减速度加快。
Air guns are widely used as shooting source in offshore seismic exploration.The research on air gun signature is very important to offshore seismic data acquisition and processing.The effects of throttling and heat conduction at gun ports affect the characteristics of air gun signature.Based on bubble oscillation theory,a numerical model is established to simulate air gun signature with consideration of air gun mechanical factors and the environmental factors around the bubble.The influence on signature is analyzed in respects of gun ports throttling and heat conduction across bubble wall by using this model.The results indicate that gun ports throttling are related to air gun ports area which can affect the velocity of high pressure air released from air gun and reduce the peak of air gun pulse;bubble oscillation accelerates fluid movement around the bubble and enhances heat conduction across bubble wall,the bubble loses more energy,and bubble oscillation attenuates rapidly.
Air guns are widely used as shooting source in offshore seismic exploration.The research on air gun signature is very important to offshore seismic data acquisition and processing.The effects of throttling and heat conduction at gun ports affect the characteristics of air gun signature.Based on bubble oscillation theory,a numerical model is established to simulate air gun signature with consideration of air gun mechanical factors and the environmental factors around the bubble.The influence on signature is analyzed in respects of gun ports throttling and heat conduction across bubble wall by using this model.The results indicate that gun ports throttling are related to air gun ports area which can affect the velocity of high pressure air released from air gun and reduce the peak of air gun pulse;bubble oscillation accelerates fluid movement around the bubble and enhances heat conduction across bubble wall,the bubble loses more energy,and bubble oscillation attenuates rapidly.
引文
[1]Keller J B,Kolodber I I.Damping of Underwater Explo-sion Bubble Oscillation[J].Applied Physics,1956,27(10):1152-1161.
[2]陈浩林,全海燕,等.气枪震源理论与技术综述[J].物探装备,2008,18(4):211-217.
[3]陈浩林,倪成洲.气枪阵列远程子波模拟与应用[J].石油地球物理勘探,2008,43(6):623-625.
[4]Ziolkowski A.A method for calculating the output pres-sure waveform from an air-gun[J].Geophys.J.R.Astr,Soc,1970,21(2):137-161.
[5]Schulze G.Physical aspects of the“air-pulse”as aseismic source[J].Geophysical Prospecting,1972,20(1):155-192.
[6]Safar M H.Efficient design of air-gun arrays[J].Geo-physical Prospecting,1976,24(4):756-772.
[7]Alexander O M G.An acoustic modeling study of seismicair gun noise in Queen Charlotte Basin[D].Canada:U-niversity of Victoria,2000:70-92.
[8]Laws R M,Hatton L,Haartsen M.Computer modeling ofclustered air gun[J].First Break,1990,8(9):331-338.
[2]陈浩林,全海燕,等.气枪震源理论与技术综述[J].物探装备,2008,18(4):211-217.
[3]陈浩林,倪成洲.气枪阵列远程子波模拟与应用[J].石油地球物理勘探,2008,43(6):623-625.
[4]Ziolkowski A.A method for calculating the output pres-sure waveform from an air-gun[J].Geophys.J.R.Astr,Soc,1970,21(2):137-161.
[5]Schulze G.Physical aspects of the“air-pulse”as aseismic source[J].Geophysical Prospecting,1972,20(1):155-192.
[6]Safar M H.Efficient design of air-gun arrays[J].Geo-physical Prospecting,1976,24(4):756-772.
[7]Alexander O M G.An acoustic modeling study of seismicair gun noise in Queen Charlotte Basin[D].Canada:U-niversity of Victoria,2000:70-92.
[8]Laws R M,Hatton L,Haartsen M.Computer modeling ofclustered air gun[J].First Break,1990,8(9):331-338.
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