北堡陆地二维地震的进展

PROGRESS OF 2-D SEISMIC EXPLORATION IN ON SHORE,BEIPU REGION

北堡陆地部分位于南堡凹陷西部 ,二维地震资料品质较差 ,除与复杂的地表条件有关外 ,主要受该区独特的地下地质条件影响 :(1)强反射界面多 ,第三系产生的多次波是导致地震资料品质差的主要原因 ;(2 )上、下第三系火山岩发育 ,屏蔽作用强 ;(3)主要目的层东营组岩性组合差、反射界面少。因此 ,须改进传统的地震方法 ,降低随机噪音 ,提高信噪比。实践表明 :在北堡的陆地部分 ,将最大纵向偏移距调整为 45 0 0m ,覆盖次数增加到90次 ,在井深 9m处激发 ,以

The land 2 D seismic data of Beipu region in west Nanpu Sag is poor in quality.This is related to complicated surface condition and unique subsurface geological condition:1.multi-intensive reflecting boundaries and multiple Tertiary waves are the main causes of the poor qaulity;2.volcanic rocks of Tertiary System developed well and their shield action is intensive;3.the major target horizon—the Dongying Formation is of poor lithological combination with less reflecting boundaries.So it is necessary to improve tranditional seismic method,decrease randon noise and increase the ratio of signal to noise.It has been proved by practice that better results could be obtained when the maximum longitudinal shift distance on Beipu land was regulated to 4 500 m,the shield times increased to 90,exiting depth set at 9 m and detected with 5 linear multiple geophone grouping.