VSP数据的逆时偏移孔径预测方法及应用  

Method and Application of Reverse Time Migration Aperture Prediction for VSP Data

作　　者：姜珊 JIANG Shan(College of Earth Sciences,Northeast Petroleum University,Daqing 163318,China)

机构地区：[1]东北石油大学地球科学学院,大庆163000

出　　处：《当代化工》2021年第2期399-402,407,共5页Contemporary Chemical Industry

基　　金：国家自然科学基金-青年项目(项目编号:41804133)。

摘　　要：与常规地面观测数据相比,VSP(Vertical Seismic Profiling)地震数据通常具有更高的信噪比,可用于井周高精度成像。然而由于VSP观测系统的特殊性,导致VSP数据对地下构造横向覆盖不均匀,VSP数据逆时偏移(RTM,Reverse Time Migration)结果中存在明显的偏移画弧现象。分析了VSP数据偏移画弧的产生机制,采用水平地层假设方法模拟地下构造,提出了一种偏移孔径的选择方法并且仅在偏移孔径范围内进行成像计算,将应用本方法前后的成像结果进行对比。测试结果表明:偏移孔径的选择对提高VSP数据RTM结果信噪比至关重要,该方法能够有效压制VSP数据RTM成像结果中的偏移画弧现象,具有良好的应用前景,对实现井周深层构造高精度成像具有重要意义。Compared with conventional surface observation data, VSP(Vertical Seismic Profiling) seismic data usually has a higher signal-to-noise ratio and can be used for high-precision imaging around the well. However, due to the particularity of VSP observation system, the lateral coverage of VSP data on the underground structure is not uniform,and there is an obvious phenomenon of migration smile in the results of RTM(Reverse Time Migration) with VSP data. In this paper, the generation mechanism of VSP data migration smile was analyzed, and the horizontal layer assumption method was used to simulate the underground structure. A selection method of migration aperture was proposed, and imaging calculation was carried out only within the range of migration aperture range. The imaging results before and after using this method were compared. The test results showed that the selection of migration aperture was very important to improve the signal-to-noise ratio of the RTM results with VSP data. The method in this paper can effectively suppress the migration smile in the RTM results with VSP data, which has a good application prospect and is of great significance for the realization of high-precision imaging of deep structure around the well.

关 键 词：VSP 逆时偏移 偏移画弧 偏移孔径 

分 类 号：TE122[石油与天然气工程—油气勘探]