巨厚黄土地区煤田地震资料采集关键技术

巨厚黄土覆盖地区土层结构疏松，地震波速度低、吸收衰减严重、次生干扰发育，资料信噪比与分辨率极低，煤田地震勘探面临诸多难题，其核心是数据采集问题。提出了利用微测井约束的瑞雷波反演技术精细刻画浅表层黄土速度结构，合理选取激发层位；利用震/检联合大基距组合技术提高单炮信噪比、压制低速强规则干扰；采取低频检波器接收以适应厚黄土层中地震波传播的衰减特征；利用多线/长排列观测技术提高目的层段的有效覆盖等技术方案。实际应用表明，通过上述4项技术的集成应用，取得了良好的效果。 

Research on key techniques for coalfield seismic data acquisition in thick loess area

Complicated conditions in thick loess-covered area cause many serious problems to the coal field seismic prospecting, which is characterized with loose soil structure, lower wave velocity, severe absorption and attenuation, serious secondary disturbances, extremely poor S/N ratio and resolution.Among these problems, field acquisition techniques are the key problems.So, some solutions are proposed, including:(1) fine portraying the loess velocity structure using Rayleigh-Wave inversion method restrained by micro-logging data, to reasonably select the excitation location; (2) applying long excite/geophone array to enhance S/N ratio of raw data and suppress the strong low speed regular interfaces; (3) adopting the low frequency geophones in order to adapt the propagation attenuation characteristics of thick loess; (4) using the multi-lines and long layout observation to improve the effective folds for targeted coal seam.The full-scale test in the thick loess area of Wanrong and Hongdong county in Shanxi indicated that through the system and comprehensive application of the above 4 key techniques, the reflection wave can be clearly recognized from raw records, and the seismic stack-profiles with events of high S/N ratio, good continuity can be obtained.The geological results have been proved perfect by 3 wells data.The application of these key techniques will basically solve the technical problems which coal field seismic acquisition work has faced in the similar areas with thick loess.