火山岩覆盖区三维地震勘探方法探究

宣化——下花园煤田位于燕山山脉的西段,区内地形复杂,成孔形式不一,采集难度大;火山岩覆盖范围广,浅层地震地质条件较差,地震记录信噪比低,静校正问题突出。为了查清宣东矿井深部煤炭资源状况,除了克服地表影响因素外,还需攻克该区火山岩对地震信号的屏蔽难题。通过对岩石出露区及黄土覆盖区进行试验分析,采取了高叠加次数等措施,有效地压制了干扰,提高了信噪比,在此基础上对地震记录进行一些有针对性资料处理技术,如绿山静较正技术等,使目的层有效波反应明显。本次勘探圈定了上覆火成岩范围及火成岩破坏区,控制了区内主要可采煤层Ⅲ3、Ⅴ2煤层的埋藏深度及构造形态,解释断层20条及Ⅲ3煤层火成岩破坏区3处,勘探成果表明,本次勘探所采用的野外采集措施和资料处理方法是行之有效的。

Probe into 3D-Seismic Prospecting in Igneous Rock Covered Regions

The Xuanhua-Xiahuayuan coalfield is situated in the western sector of the Yanshan Mountains. Since the relief in the area is complex, drilling methods of boreholes are different, wide igneous rock covering, poor shallow seismic geological conditions, low seismic record S/N ratio, thus caused conspicuous problems in statics. To identify coal resources in deep part of the Xuandong minefield, except have to overcome surface impacting factors, but also the hard nut of seismic signals guarded by igneous rocks. Through testing and analyses in rock outcropped area and loess covered area, measures including high stacking folds have adopted, thus suppressed interferences and improved S/N ratio effectively. On this basis, target-oriented seismic record data processing technologies carried out, such as the Green Mountain statics etc. to make reaction of etfective wave from target layers much better. This prospecting has cycled out overlying igneous rock covered range and destructed area; controlled main mineable III3 and V2 coal seams buried depths and structural configurations; interpreted 20 faults and 3 igneous rock destructed zones of III3 coal seam. The prospecting result has demonstrated that the field data acquisition measures and processing methods adopted are tried and true.