提高黄土塬地区地震波激发质量的几点认识

黄土塬地区表层黄土厚度达0～400m,土质疏松,纵横向变化剧烈,地震波的吸收和衰减严重,干扰波发育,记录信噪比极低,给地震数据采集尤其是地震波激发环节造成了巨大的困难,被认为是世界级难题。通过在长武黄土塬区进行地震波激发技术攻关,取得了一些新的认识:巨厚黄土塬地区在含水黄土层中或在速度1500～1800m/s层中采取单深井激发,能够有效保证地震资料的信噪比,为黄土塬地区的激发开辟了新的研究方向,使用的60m"超深单井"在黄土塬地区开了个先河;"超大基距"组合井打破了"标准"爆炸半径理论的限制,丰富和发展了黄土塬地区勘探理论认识;黄土结核的突破使激发效果得到了明显的提升。

On Improving Seismic Wave Explosion in Loess Yuan Area

The surface thickness in Loess Yuan area ranges from 0 to 400 meters, the soil is loose, both the vertical and horizontal directions are changeable dramatically, the absorption and attenuation of seismic waves are serious and the development of interference wave and the SNR records are quite low, which caused a great difficulty in seismic acquisition, especially in the process of seismic wave explosion. Through working on the seismic wave explosion technology in in Loess Yuan area of Chang Wu region, we gained some new understandings： Adopting deep single hole for huge thick Loess Yuan area in aqueous loess layer or loess layer in which the speed is the between 1500 and 1800m/s , which could effectively guarantee SNR of seismic data, and it opened a new research direction for seismic wave explosion in Loess Yuan area. It was the first time to adopt 60m single ultra--deep well in this area. Ultra--large grouping length of multi--well array breaks the limit of ‘standard＇ blast radius theory, which enriched and developed the exploration knowledge and theory for Loess Yuan area as well. Loess concretion made distinguished improvement in seismic wave explosion.