| With the further development of Bohai oilfield,geological interpretation needs higher and higher requirement on the precision of offshore seismic data.Jinzhou 20-2 condensate gas field has been put into production for many years,the three-dimensional seismic data of this area were collected in 1985,when it was generally affected by the acquisititon and processing conditions and technologies,as well as the quality was poor,which was far from meeting the needs of current production,especially it even lead to the serious contradiction between the calculation of natural gas reserves by volume method and dynamic production,which could not accurately reflect the real situation of the gas field.Therefore,for jinzhou 20-2,secondary threedimensional collection is urgently needed,and the application technology of three-dimensional seismic collection has become mature in the bohai sea.Three-dimensional seismic exploration is gaining popularity.The huge increase in exploration costs has become a problem that various oil fields have to face.Therefore,it is very important to the design of seismic data collection.In this paper,the design flow of the three-dimensional seismic data acquisition and observation system and the ocean bottom cable acquisition technology are discussed,and the basic design flow and principle of the three-dimensional seismic data acquisition and observation system are summarized comprehensively.Based on the comparative analysis of existing seismic data,the design of the observation system is carried out according to the geological requirements.The parameters of the observation system,such as resolution,bin size,offset,migration aperture,non-longitudinal distance and coverage times,are optimized.Based on the analysis of the test data in the work area to meet the geological needs of the work area,the influence of the design parameters of three-dimensional seismic observation system on the quality of acquisition data and the quality of subsequent processing and interpretation data is studied,and the formal production acquisition parameters in the work area are finally determined.Through the research of lighting analysis technology,the lighting process suitable for the evaluation of observation system is given.Finally,the lighting analysis and trial calculation of the theoretical model are carried out.A three-dimensional seismic-geological model for the target area of the sea is established.Different observation systems are designed for the target area of the model.The illumination of different observation systems is analyzed and compared,and the optimal parameters of the observation system are determined.Through the design of observation system,the quality of data is improved and the design of ocean bottom cable observation system in Bohai tectonic belt is guided. |
