辽西深反射地震勘探采集试验

Field Test on Deep Seismic Reflection Acquisition in the West of Liaoning Province

深反射地震勘探是目前研究和分析地下深部构造最有效的方法之一。为了查明辽西地区深部构造信息,在该地区布设一条16.9km的深反射地震剖面。由于该地区的地震地质资料有限,为了能够获取深部地层的地震反射信号,开展了辽西地区的深反射地震勘探采集参数试验。本次地震采集参数试验采用炸药震源、428XL地震仪和SG-10低频检波器,固定采集参数为:采样间隔1ms、道间距20m、记录长度15s。采集参数试验主要针对激发因素(激发深度、药量、组合井激发)和接收因素(组合低频检波器)进行了较为全面的试验工作。依据采集的地震记录确定所研究的主要目的层为6.5s反射信号,通过对不同激发因素和接受因素单炮记录中目的层信号能量及信噪比的比较,确定适合于该地区的最佳激发参数和接收参数为:井深15m、药量12kg;井组合采用单井和三井组合相结合;检波器组合采用点组合方式。研究结果表明,在辽西地区,通过增加激发深度、增加药量、采用组合井激发和组合低频检波器、延长记录时间等措施可以获得地下更深部的反射信息。

Seismic exploration is one of the most effective method on the research and analysis of underground structures.In order to find out the deep structural information of the west of Liaoning Provience,we emplaced a deep reflection seismic profile of 16.9 km in the region.As the region’s seismic and geological data is limited,we carried out a test on the parameters of deep reflection seismic＆amp;nbsp;acquisition for the obtaining of seismic reflection signals from the deep strata.This test uses dynamite source,428XL seismograph and SG 10 low-frequency detectors,fixing acquisition parameters as sampling interval 1 ms, channel spacing 20 m, and record length 15 s. A more comprehensive experimental work on the acquisition parameters of motivating factors （excitation depth,explosive dose, combination of well excitation）and receiving elements （combined low frequency geophone）is launched. Based on the seismic records,the authors treat 6.5 s reflected signal as the main reflection layers.By comparing and analyzing the signal energy and the SNR of the target layers,we obtain the optimal excitation and receive parameters as depth 15 m,dose 12 kg;combination of single well and Mitsui;geophone array using dot combinations.The results of the research show that we are able to obtain deeper reflect information by increasing the exciting depth,the charge,employing combination of well and low-frequency detector and extend recording time etc.