十字交叉域去噪技术在西部地区地热勘探中的应用

Application of Cross Array Denoising Technology on Geothermal Exploration in Western China

在西部复杂地区开展干热岩地热勘探,因特殊地表和地下地震地质条件,采集的原始三维地震资料中面波广泛发育,干扰严重,常规二维速度滤波难以达到预期效果,甚至损伤低频有效信号。结合小面积三维地震资料特点,充分利用三维数据空间分布特征,在十字交叉域利用锥形滤波去除面波干扰,从单炮记录、叠加剖面及信噪比分布等方面对比分析了其应用效果,压制了面波干扰,保留了有效信号,刻画了丰富的波组信息,提高了信噪比,为后续资料解释工作提供了坚实的数据基础,也为西部复杂地区地热勘探工作提供了技术支撑,具有良好的应用效果和潜力。

Geothermal exploration of hot dry rock resources is carried out in the complex areas in western China.Due to the special surface and underground seismic-geologic conditions,surface waves are widely developed in the original collected 3D seismic data,and the interference is serious.Conventional 2D velocity filtering is usually difficult to achieve the expected effect,and would even damage the low-frequency effective signals.Combined with the characteristics of 3D seismic data acquired in small areas,considering the spatial distribution characteristics of the 3D data,we use conical filtering to remove surface wave interference in the cross array domain,compare and analyze its application effects from the aspects of the shot gather recordings,stacked profiles and the signal-to-noise ratio distribution.We find that the surface wave interference is suppressed,the effective signals are retained,the rich wave group information is vivid,and the signal-to-noise ratio is improved.It provides a solid data base for the following data interpretation,and also provides a technical support for the geothermal exploration in the complex areas in western China.This technology shows good application effect and promising potential.