CAJ | 학술논문

在浅水环境中,利用频率域海洋可控源电磁法探测油气藏薄层面临着挑战,这是因为空气波支配着电磁响应而它只含有少量海底电阻率结构的信息.本文研究了空气波对时间域可控源电磁(CSEM)响应的影响. 空气波到达时间取决于海水深度.在浅水区空气波到达早,而在深海水区空气波到达晚,空气波与来自深部电阻体的电磁波出现在不同时间段.虽然在中等深度的海水区空气波和来自深部电阻体的电磁信号几乎同时到达,但与不含有油气藏的背景模型相比,仍可以看到明显的异常.浅水区勘探的好处在于可以使用表面拖曳系统.
재천수배경중,이용빈솔역해양가공원전자법탐측유기장박층면림착도전,저시인위공기파지배착전자향응이타지함유소량해저전조솔결구적신식.본문연구료공기파대시간역가공원전자(CSEM)향응적영향. 공기파도체시간취결우해수심도.재천수구공기파도체조,이재심해수구공기파도체만,공기파여래자심부전조체적전자파출현재불동시간단.수연재중등심도적해수구공기파화래자심부전조체적전자신호궤호동시도체,단여불함유유기장적배경모형상비,잉가이간도명현적이상.천수구감탐적호처재우가이사용표면타예계통.
In shallow water environments, the frequency domain, marine controlled source electromagnetic (CSEM) method faces a challenge for detecting thin hydrocarbon reservoirs because the airwave dominates electromagnetic responses and contains little information about resistivity structure of the seabed. In this paper, airwave effects on time domain (or transient) CSEM responses are investigated. The arrival time of the airwave depends on the water depth. The airwave arrives earlier in shallow water and later in deep water environments and it occurs at different time than the signals traveling through the deep resistor. Although in an intermediate water depth the airwave and the signal from the deep resistivity arrive at about the same time, one can still see a clear anomaly compared to the background model without hydrocarbon reservoirs. For shallow water surveys, one has the added advantage that a surface towed system can be used.