基于实际数据驱动的非纵波场模拟分析

发布时间：2018-04-23 23:07

本文选题：非纵观测系统 + 非纵距　；参考：《地球物理学进展》2017年06期

【摘要】：在黄土塬、山地等低信噪比地区,单炮近道受面波、激发噪声等影响,地震资料品质极差.为此提出了非纵观测,使目的层反射波避开近道干扰,来提高地震资料的信噪比.如何选择合适的非纵距进行观测系统设计?常规方法是采用建立三维地质模型,利用射线追踪或波动方程正演模拟地震记录选择观测系统的非纵距,但由于地质现象的复杂性、建模软件的应用性、建模方法适用条件的局限性等等,使得在实际生产应用中,模拟出的地震记录还存在一些不足之处.为此融合探区以往的地震资料,建立了如下流程确定合理的非纵距:首先搜集探区以往的炮集数据,在炮集数据上拾取地震波(初至波、反射波和面波)和目的层倾角,获取地震波的走时、均方根振幅、主频、相位等信息,建立炮检距与分析地震波属性值(走时、均方根振幅、主频、相位等)的关系曲线;然后根据地质任务设计单炮点的非纵观测系统,根据炮检距选择对应地震波的关系曲线相应的属性值,模拟地震记录;最后根据目的层反射波能否有效避开面波、初至波、近道干扰,确定观测系统非纵离.通过实例验证,对于地质构造复杂、资料信噪比低的地区,模拟的地震记录更符合探区地质构造特点,能有效地指导观测系统非纵距的设计,达到合理压制噪声和提高地震资料信噪比的目的,克服了传统宽线压噪能力低和三维采集投资过大的矛盾.
[Abstract]:In low signal-to-noise ratio (SNR) areas such as Loess Plateau and mountainous region, the quality of seismic data is very poor due to the influence of surface wave and excitation noise. In order to improve the signal-to-noise ratio (SNR) of seismic data, it is proposed that the reflection wave of target layer avoid near-channel interference. How to select the appropriate non-longitudinal distance for the design of the observation system? The conventional method is to establish a three-dimensional geological model and use ray tracing or wave equation forward modeling to simulate seismic records to select the non-longitudinal distance of the observation system. However, due to the complexity of geological phenomena, the application of the modeling software is obvious. Because of the limitation of the applicable conditions of the modeling method, there are still some shortcomings in the simulated seismic records. For this reason, the following flow chart is established to determine the reasonable non-longitudinal distance by combining the seismic data of the exploration area: firstly, the seismic wave (first arrival wave, reflection wave and surface wave) and the inclination angle of the target layer are collected from the seismic data collected from the exploration area, and the seismic waves (first arrival wave, reflected wave and surface wave) are picked up on the data of the exploration area. The travel time, root mean square amplitude, main frequency, phase and other information of seismic wave are obtained, and the relation curves between the offset and the characteristic value of seismic wave (travel time, root mean square amplitude, main frequency, phase, etc.) are established. Then, according to the geological task, we design a non-general survey system of single shot point, select the corresponding attribute value of the corresponding seismic wave curve according to the offset, and simulate the seismic record. Finally, according to whether the reflection wave of the target layer can effectively avoid the surface wave, the first arrival wave, The short track interference is used to determine the non-longitudinal separation of the observation system. It is verified by practical examples that for areas with complex geological structure and low signal-to-noise ratio of data, the simulated seismic records are more in line with the characteristics of geological structure in the exploration area, and can effectively guide the design of the non-longitudinal distance of the observation system. The aim of reasonably suppressing noise and improving signal-to-noise ratio of seismic data is achieved, and the contradiction of traditional wide line noise reduction ability and excessive investment in 3D acquisition is overcome.
【作者单位】：东方地球物理公司采集技术中心;东方地球物理公司辽河物探处;
【基金】：国家重点研发计划深地专项项目(2016YFC0601100)赞助
【分类号】：P631.4

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