潮间带地震资料采集放线模式探讨

Study on the mode of laying cable for seismic data collection in shoals

潮间带地震资料采集施工中的放线精度问题影响地震资料的品质。以SK工区为例,分析了潮汐的变化情况,选取在低潮期进行放线。为了保证放线质量,根据水深及实际施工情况,将放线模式分为两种,水深0 m^1.5 m以及水深1.5 m以上。这两种分类主要基于放线人员的安全,水深小于1.5 m放线人员可以在水中直接放线,而水深大于1.5 m需借助于船只放线。在水深0 m^1.5 m范围内为了保证检波器的耦合性,选用带尾椎的陆用压电检波器,借助于新研制的检波器下置杆将检波器放置于淤泥层下;而水深大于1.5 m,选用没有尾椎的水域压电检波器,借助于船只进行实时定点放线。

During the process of seismic exploration data acquisition,accuracy of laying cable for seismic data collection in shoals affects the accuracy of seismic acquisition.Taking the SK area as an example,the changing of tide is analyzed,and the period for laying cable is selected at low tide.In order to ensure the quality of laying cable,according to the water depth and the actual construction situation,the laying mode is divided into two groups.The water depth is 0-1.5m and the water depth is more than 1.5m.These two classifications are mainly based on the safety of the operator.With a water depth less than 1.5 m the operator can lay cable directly in the water,while with water depth greater than 1.5 m the operator needs to use the boat to lay cable.In order to ensure the coupling of the geophone in the depth range of 0-1.5m,a terrestrial piezoelectric geophone with tail vertebra is selected,and the geophone is placed under the silt layer with the help of the newly developed tools for embedding geophone;and when the water depth is deeper than 1.5m,the hydro-geophone without tail vertebra is selected to make real-time location and lay-out with the aid of ships.