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公开(公告)号:EP0381367A3
公开(公告)日:1991-09-18
申请号:EP90300755.7
申请日:1990-01-24
发明人: Sallas, John J.
IPC分类号: G01V1/02
CPC分类号: G01V1/006 , Y10S367/905
摘要: A method of reducing horizontally propagating pressure waves in marine seismic exploration to improve the signal-to-noise ratio at associated receivers and reduce interference at unassociated receivers, comprises providing marine vibrators (12,14,16,18) in an array with a given separation between each vibrator, so that horizontally propagating pressure waves from the vibrators which generally traverse the array are out-of-phase at most frequencies of vibration. The amplitude output from each vibrator varies with the output frequency of each vibrator to maximise the cancellation of out-of-phase pressure waves along the array. A receiver, which usually includes a plurality of hydrophones (34,36,38) disposed in a streamer (20), is spaced from the marine vibrators at a distance sufficient to establish the receiver as being in the far-field. The output of each of the marine vibrators is locked in phase and frequency with a known pilot signal so that downwardly propagating pressure waves are substantially unaffected. The overall effect is a narrowing of the radiation pattern of the pressure waves. The resulting radiation pattern effectively directs pressure waves downwardly toward an underwater land formation; and reduces horizontally propagating pressure waves which normally result in interference with marine seismic receivers.
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公开(公告)号:EP0390560A3
公开(公告)日:1992-04-08
申请号:EP90303365.2
申请日:1990-03-29
发明人: Sallas, John J.
CPC分类号: G01V1/04 , G10K11/178 , G10K2210/10 , G10K2210/3037 , G10K2210/501
摘要: Air wave noise caused by vibrating baseplate (10) on a seismic vibrator is reduced or eliminated by detecting the acceleration of the baseplate using transducers (12), and therefrom forming a counterpart wave which is equal in amplitude but opposite in phase, transmitted through a speaker (24) to produce an opposite air wave to cancel the baseplate air wave.
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公开(公告)号:EP0390560A2
公开(公告)日:1990-10-03
申请号:EP90303365.2
申请日:1990-03-29
发明人: Sallas, John J.
CPC分类号: G01V1/04 , G10K11/178 , G10K2210/10 , G10K2210/3037 , G10K2210/501
摘要: Air wave noise caused by vibrating baseplate (10) on a seismic vibrator is reduced or eliminated by detecting the acceleration of the baseplate using transducers (12), and therefrom forming a counterpart wave which is equal in amplitude but opposite in phase, transmitted through a speaker (24) to produce an opposite air wave to cancel the baseplate air wave.
摘要翻译: 通过使用换能器(12)检测基板的加速度来减少或消除由振动基板(10)在地震振动器上引起的空气波浪噪声,并且由此形成相反的幅度相反的相对波, 扬声器(24)产生相反的空气波以抵消基板空气波。
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公开(公告)号:EP0381367A2
公开(公告)日:1990-08-08
申请号:EP90300755.7
申请日:1990-01-24
发明人: Sallas, John J.
IPC分类号: G01V1/02
CPC分类号: G01V1/006 , Y10S367/905
摘要: A method of reducing horizontally propagating pressure waves in marine seismic exploration to improve the signal-to-noise ratio at associated receivers and reduce interference at unassociated receivers, comprises providing marine vibrators (12,14,16,18) in an array with a given separation between each vibrator, so that horizontally propagating pressure waves from the vibrators which generally traverse the array are out-of-phase at most frequencies of vibration. The amplitude output from each vibrator varies with the output frequency of each vibrator to maximise the cancellation of out-of-phase pressure waves along the array. A receiver, which usually includes a plurality of hydrophones (34,36,38) disposed in a streamer (20), is spaced from the marine vibrators at a distance sufficient to establish the receiver as being in the far-field. The output of each of the marine vibrators is locked in phase and frequency with a known pilot signal so that downwardly propagating pressure waves are substantially unaffected. The overall effect is a narrowing of the radiation pattern of the pressure waves. The resulting radiation pattern effectively directs pressure waves downwardly toward an underwater land formation; and reduces horizontally propagating pressure waves which normally result in interference with marine seismic receivers.
摘要翻译: 一种在海洋地震勘探中减少水平传播的压力波的方法,以提高相关联的接收机处的信噪比并减少在不相关的接收机处的干扰,包括提供具有给定的阵列的海洋振动器(12,14,16,18) 每个振动器之间的分离,使得来自振动器的水平传播的压力波通常穿过阵列在最多的振动频率处是不相位的。 来自每个振动器的振幅输出随着每个振动器的输出频率而变化,以最大程度地消除沿阵列的异相压力波的消除。 通常包括设置在拖缆(20)中的多个水听器(34,36,38)的接收器与海洋振动器间隔开足以使接收器处于远场的距离。 每个海洋振动器的输出以已知的导频信号锁相在相位和频率上,使得向下传播的压力波基本上不受影响。 整体效果是压力波辐射图的变窄。 所产生的辐射图有效地将压力波向下引向水下地面; 并减少水平传播的压力波,这通常会导致与海洋地震接收器的干扰。
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