城区三维地震观测系统设计及应用效果

城镇大型障碍区布设观测系统面临的主要困难有:如何避开障碍物,选择什么参数确保面元属性均匀、最佳压制噪声,以得到好的反射资料。鉴于现有的勘探装备和技术潜力,本文提出一套从物理点优化调整到辅助检测的方法。其基本思路是:利用高精度数字卫星照片和地震测量成果,对设计的规则观测系统进行反复调整,尽量避开障碍物,计算出调整后的覆盖次数、炮检距及方位角分布情况,设计出适用于障碍区的不规则观测系统。文中总结了几条设计原则,并给出相应的调整方法和辅助检测手段。通过合理调整炮点和检波点的位置,成功地解决了穿越大型障碍区时有效接收和安全激发的问题,确保了面元内覆盖次数、炮检距、方位角等属性均匀,在多块三维资料采集应用中取得了理想效果。

Design of 3-D seismic geometry in urban area and applied effects.

The main difficulties in configuration of geometry in larger obstacles of cities and towns are as follows: how to avoid obstacles, which parameters should be selected in order to ensure the bins to have uniform attributes and optimally depress the noises and gain good data. Based on existing prospecting equipment and technical potential, the paper presented a set of methods from optimal ad- justment of physical points to auxiliary check. The basic ideas as follows: using high-precision digital satellite photos and seismic surveying results to do repeated adjustment of designed regular geometry to avoid the obstacles as far as possible, to compute distributed situation of folds, offsets and azimuths and design irregular geometry suitable for obstacle areas. Some designing principles were summarized and associated adjusted methods and auxiliary tools were given in the paper. The issues of effective receiving and shooting in safety way going through larger obstacles were successfully solved by reasonable configuration and adjustment of shot-points and receiver-points, ensuring uniform attributes such as folds, offsets and azimuths within bins and achieving ideal results in many blocks of 3-D seismic data acquisition.