富县黄土塬区二维地震直测线施工方法及效果

富县探区位于鄂尔多斯盆地陕北斜坡东南部,断裂不发育,属于山区地形,表层存在着较厚的低速黄土,同时具黄土塬的特点.对二维直测线采集应用以下技术:①多种方法相结合的高精度表层调查获得准确的表层结构以指导设计井深;②"四避四就"的原则和变面元观测系统灵活布设炮点;③折射波静校正解决中、长波长静校正问题,地表一致性剩余静校正解决高频短波长静校正问题.取得了与弯线地震勘探同样的效果.

Special technologies used in the arrangemnt and acquisition of the 3D direct seismic lines in the loess tableland area of Fu County, Shaanxi Province and their application result

The exploration area in Fu County is located in the southeast of the North Shaanxi slope in Ordos Basin,and fault is not developed there.The ground feature of the area belongs to mountainous landform,and there is thicker low-speed loess in the surface layer of the area.The studied area presents the characteristics of loess tableland.Three technologies as follows are applied in the arrangement and acquisition of the 2D direct seismic lines in the area:(1)acquitting accurate surface structure by combining several high-precision surface survey methods to guide the design of well depth;(2)flexibly arranging shot-points by using the principle of "avoiding high and selecting low,avoiding steep and selecting gentle,avoiding thick and selecting thin,avoiding yellow and selecting red" and variable flexi-bin geometry;(3)using refraction static correction for the correction of medium--long wave and surface-consistent residual static correction for the correction of high-frequency short wave.By using the technologies,the same result as slalom seismic prospecting is obtained.