电火花震源在四川盆地VSP勘探中的应用  

Application of spark source to VSP survey in Sichuan Basin

作　　者：刘飞 秦俐 李敬益 马路 谭兴 Liu Fei;Qin Li;Li Jingyi;Ma Lu;Tan Xing(New Resources Geophysical Exploration Division,CNPC BGP Inc.,Chengdu,Sichuan 610213,China)

机构地区：[1]中国石油集团东方地球物理勘探有限责任公司新兴物探开发处西南经理部

出　　处：《天然气勘探与开发》2022年第1期40-46,共7页Natural Gas Exploration and Development

摘　　要：电火花是一种低能叠加激发震源,相对炸药震源,具有环境危害小、能量可扩充、操作安全等优势,此前在四川盆地VSP作业中还未开展应用。为了试验电火花震源在VSP资料采集中的适应性,在四川盆地泸州区块北部开展了电火花震源与炸药震源的对比性现场试验。从资料采集及其处理分析结果可以看出:①电火花震源的总能量较弱,其分辨率和信噪比都略低于炸药震源;②电火花震源子波的稳定性容易受到现场激发条件的影响而变差;③电火花震源激发获得的VSP数据的Z分量初至波起跳干脆、清晰,上行波和下行波关系清楚;④处理后获得的走廊叠加剖面与合成地震记录和地震剖面上主要地质层位波组特征一致性较好。通过现场试验,结论认为:相比炸药震源,电火花震源在四川盆地中浅层VSP勘探中可以起到很好的补充作用,当储层分布深度大于3500 m时,建议采用炸药震源或更高功率的电火花震源。As low-energy stacked seismic source featured by a little environmental harm,expansible energy,and operational safety compared with dynamite source,spark source has not yet been utilized in VSP prospecting in Sichuan Basin.To check its feasibility in VSP acquisition,a comparative test on both spark and dynamite source was carried out in northern Luzhou area,Sichuan Basin.Results show that(1)spark source is inferior to dynamite source in total energy,resolution,and signal to noise ratio;(2)a spark wavelet may become unstable in the case of poor excitation condition;(3)spark excitation yields well-marked first break of Z-component and upgoing and downgoing wave in VSP data;and(4)the corridor stacked section agrees with synthetic seismogram and surface seismic section in the reflection of major geologic horizons.In conclusion,spark source is a supplement to dynamite source in some shallow and middle VSP survey in Sichuan Basin.For those zones of interest below 3500 m,it is recommended to use dynamite source or high-power spark source.

关 键 词：四川盆地 VSP 电火花震源 炸药震源 勘探 现场试验 

分 类 号：P631.4[天文地球—地质矿产勘探]