兴隆台城区三维炮点偏移校正技术

在城区进行三维地震勘探时，如果设计的激发点离建筑物较近，无论采用炸药震源还是可控震源，都会对建筑物构成不同程度的威胁。因此，观测系统中设计的部分激发点(炮点)位置和实际施工中采用的位置往往有偏差，从而给地震数据处理带来许多麻烦。为解决此问题，本文针对我国东部地区近地表速度相对较稳定的特点，提出了利用大炮初至时距曲线区域综合量板进行炮点偏移校正的方法，即把若干个正常炮检点(炮点和检波点坐标位置与施工作业班报记录相吻合)的初至波旅行时绘制成炮检距一初至波旅行时区域综合量板，利用量板中的初至波旅行时和炮检距之间的数量关系来寻找炮点偏移的真实位置，从而达到炮点偏移校正的目的。实际地震数据处理效果证明，该方法能一次性且较准确地完成所有炮点偏移校正，对我国东部地区陆上地震勘探炮点偏移校正具有普遍适用性。

Correction of 3D shot-points offsets in Xinglongtai urban district

When 3D seismic exploration is carried out in urban districts,if designed shot-points are near the buildings,the safety problem of buildings always exists in some degree whether using dynamite source or vibroseis.Therefore,there is often deviation of the positions of some designed shot-points in geometry from the practically used positions in field production,which brings a lot of troubles in seismic data processing.In order to solve this problem,the paper presented using synthetic regional first break time-distance template of shot records for correction of shot-points offset faced with the character of more stable near-surface velocity in the east of China.The method first draws first break travel-times of some normal shot and receiver points (coordinate positions of shot and receiver coincide with recorded positions in log book of field production) as synthetic regional offsets-first break travel-times template,then uses the numeric relationship between offsets and first break travel-times to look for real positions of shot-points offsets,which reaches the goal of correction of shot-points offsets.The results of practical seismic data processing showed that the method can accurately finish the correction of total shot-points offsets on its first operation and has popular adaptability for the correction of shot-points offsets in land seismic exploration of the east of China.