山区三维地震探采对比分析——以阳泉五矿中央采区三维地震勘探工程为例
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摘要
阳泉煤业集团各矿区浅表层地震地质条件均十分复杂,多数勘探区表层都存在激发效果很差的黄土层和卵石层,地形高差也多在160～400m之间,共中心点道集反射点离散严重。该区小型挠曲和陷落柱十分发育,有的区域陷落柱甚至达到40余个/km2。恶劣的地震地质条件,严重影响三维地震勘探效果,增加资料处理成像的难度及降低解释的准确性。阳泉五矿中央采区地震勘探共圈定陷落柱27个,断层12条,其中验证区内陷落柱11个,断层4条。而验证范围内采掘实际揭露陷落柱21个,断层11条。例举实例,分析误差存在的因素除了部分陷落柱与断层规模较小出现漏报外,受分辨能力的影响,地震勘探圈定的构造往往是距离很近的2个异常体的共同响应;再有在勘探边缘,地震信息较小也会导致漏报;另外山区反射点离散难以做到共反射点叠加,进而造成成像品质不高和分辨率降低,也是漏报的原因之一。针对目前地震成果验证没有统一的标准,以陷落柱为例,提出探采对比评价可从三个方面开展,并详细说明其评价方法。通过对阳泉五矿中央采区三维地震探采对比,指出目前煤田山区三维地震勘探还存在五个方面的技术问题。
Coalmines of the Yangquan Coal Group have very complex near-surface seismic-geologic conditions,poor shot effective loess and pebble beds are existed on surface of many exploration areas,relief height differences between 160～400m,serious variances are existed in common-midpoint gather reflection points.The area has well developed small flexures and subsided columns(some places 40 more per square kilometer).Poor seismic-geologic condition seriously impacts 3D seismic prospecting effects,increases data processing and imaging difficulties,lowers down interpretation accuracy.The central winning district of Yangquan No.5 coalmine has circled out 27 subsided columns and 12 faults through seismic prospecting,in which,11 subsided columns and 4 faults validated.While in the validating area,21 subsided columns and 11 faults have revealed through winning and opening.Analyzed examples of error factors except fail to report small scale subsided columns and faults,there still have: because of low resolution,sometimes the circled structures are common-response of two near anomalous bodies;again,in the prospecting margin area,because of poor seismic signals;in addition,reflection point variances in mountainous areas are difficult to carry out common-reflection point stacking caused poor imaging and low resolution also the reason of fail to report.In allusion to no unified standard for seismic result verification,to take subsided column as example,suggested that the correlation of exploration and mining information can be carried out from 3 aspects and explained assessment method in detail.Through the correlation in central winning district of Yangquan No.5 coalmine,pointed out present coalfield 3D seismic prospecting still has problems in 5 aspects.
Coalmines of the Yangquan Coal Group have very complex near-surface seismic-geologic conditions,poor shot effective loess and pebble beds are existed on surface of many exploration areas,relief height differences between 160～400m,serious variances are existed in common-midpoint gather reflection points.The area has well developed small flexures and subsided columns(some places 40 more per square kilometer).Poor seismic-geologic condition seriously impacts 3D seismic prospecting effects,increases data processing and imaging difficulties,lowers down interpretation accuracy.The central winning district of Yangquan No.5 coalmine has circled out 27 subsided columns and 12 faults through seismic prospecting,in which,11 subsided columns and 4 faults validated.While in the validating area,21 subsided columns and 11 faults have revealed through winning and opening.Analyzed examples of error factors except fail to report small scale subsided columns and faults,there still have: because of low resolution,sometimes the circled structures are common-response of two near anomalous bodies;again,in the prospecting margin area,because of poor seismic signals;in addition,reflection point variances in mountainous areas are difficult to carry out common-reflection point stacking caused poor imaging and low resolution also the reason of fail to report.In allusion to no unified standard for seismic result verification,to take subsided column as example,suggested that the correlation of exploration and mining information can be carried out from 3 aspects and explained assessment method in detail.Through the correlation in central winning district of Yangquan No.5 coalmine,pointed out present coalfield 3D seismic prospecting still has problems in 5 aspects.
引文
[1]江苏煤炭物探测量队.阳煤五矿中央采区三维地震勘探报告[R].南京:江苏煤炭物探测量队,1997.
[2]中国煤田地质总局物测队.阳煤五矿西北采区三维地震勘探报告[R].河北邢台:中国煤炭地质总局物测队,2000.
[3]中国煤田地质总局物测队.阳煤五矿四采区三维地震勘探报告[R].河北邢台:中国煤炭地质总局物测队,2002.
[2]中国煤田地质总局物测队.阳煤五矿西北采区三维地震勘探报告[R].河北邢台:中国煤炭地质总局物测队,2000.
[3]中国煤田地质总局物测队.阳煤五矿四采区三维地震勘探报告[R].河北邢台:中国煤炭地质总局物测队,2002.
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