【摘要】 吉林探区是一个勘探程度很高的地区,但在一些城区还存在许多地震空白区,采用三维线束状特殊观测系统可以较好地解决复杂地表条件下的地震采集工作。本文阐述了过乾安城区的特殊观测系统设计及其效果。由于城区内炮点缺失,必然造成小炮检距缺失,浅层资料不完整,采用正常观测系统难以达到采集目标。通过在城区加密接收线,可以有效弥补由于城区炮点缺失造成的小炮检距缺失,保证浅层资料的完整,同时可以有效增加覆盖次数,压制城区内的环境噪声;由于城区内小药量激发造成的深层反射能量较弱,因此采用在城外加密炮点,可以有效增加深层反射能量。该方法有利于城内、城外地震资料的衔接,有利于资料处理,便于野外施工,采用这种特殊观测系统可以取得较好的地震采集效果。更多还原

【Abstract】 Jilin surveying area is mature prospecting area, but there exist many urban areas where the seismic exploration has not been carried out. Using 3-D swath special geometry can better conduct the seismic acquisition in complex surface conditions. The paper expounded the design of special geometry in Qian’an urban area and its applied effects. The missing of the shot-points in urban area resulted in missing of short offsets that made the shallow data incomplete, which is difficult to acquire the acquisition targets by using normal geometry. Infilling receiver lines in urban area can effectively compensate the missing short offsets because of shortage of shot points in urban area, which guaranteed the completeness of shallow data and also can effectively increase folds and suppress environmental noises in urban area at the same time; the deep weak reflected energy caused by small charge size in urban area can be complemented by infilling shot points outside urban area that can effectively increase the deep reflected energy. The method is of benefit to link up the seismic data inside and outside the urban area,which is of benefit to data processing and convenient to field construction. The practice showed that using this special geometry could obtain good acquisition effects.更多还原