黄土塬区二维地震施工技术初步研究

A Pilot Study on 2D Seismic Prospecting Operation Techniques in Loess Tableland

某勘探区位于宁夏回族自治区南部固原市,具黄土高原地貌特征:黄土冲沟发育,地形切割剧烈,部分沟壁近乎直立,地形总体北低南高,最大高差大568m。该区基岩少有裸露,大多数被第四系所覆盖,盖层厚度一般大于100m,地震激发条件属Ⅲ类区,原始资料存在严重的静校正问题。该区目的层主频率为30Hz,通过试验,采用井深20m、药量3kg及多井组合激发,同时增加排列长度,提高覆盖次数等野外技术措施,改善资料品质。

An exploration area in Guyuan City, southern Hui Autonomous Region of Ningxia is provided with loess plateau relief features, has developed gullies, strongly dissected terrain, part of gully walls approximately vertical, generally low in north and high in south, maximum height difference 568m. Bedrocks in the area are rarely outcropped, mostly covered by Quaternary System, overburden thickness commonly 〉100m. Seismic shot condition belongs to III category, source data need to be static corrected. Target stratum predominant frequency is 30Hz, through testing we use 20m borehole depth, 3kg charge and multiple shot arrays, field technical measures to increase array length and fold improve data quality.