Research On Fidelity Processing Method Of Three-dimensional Seismic Data

Chunguang Oilfield is the main block for high-efficiency exploration in Henan Oilfield.By the end of 2014,a total of more than 30 million tons of reserves have been submitted.The research work of the Shawan Formation is based on the pre-stack time migration of the frequency-raised seismic data.With the deepening of the research work,some wells fail under the data of the poststacking frequency-corrected data,indicating the existence of the existing frequency-raised data.The multi-solution is not able to meet the fine characterization of the thin interbedded layers of the Shawan Formation.In 2014,through fine comparison,the sub-series system subdivided the I sand group and the II sand group of the main target layer Shawan Formation into seven by the original two pinch-out zones,and the existing seismic data with a frequency of 60 Hz.The data does not meet the needs of identifying subdivided sand bodies.Through forward modeling and frequency analysis analysis,to identify the subdivided single sand body,the main frequency of the seismic data should be above 75 Hz.At the same time,through the comparison of old and new seismic data and the interpretation analysis,it is considered that the latest data has better signal-to-noise ratio and resolution than the old one,but the fidelity is relatively poor.For example,the spring 45 well area is predicted to be unconformed by using the sidelobe effect.In the process of accumulation mode,it is affected by the fidelity.In order to improve the recognition accuracy of lithologic traps,it is necessary to improve the resolution and signal-to-noise ratio of the data under the premise of fidelity,so it is necessary to deal with the "three highs" in the process.Qualitative and quantitative constraints are made,so that the data can be relied upon for the control of “three highs”.Through the research on the fidelity processing method of three-dimensional seismic data in the southwest of Chunguang exploration area,the processing work of three-dimensional seismic data covering 350 km 2 in the Southwest has been completed,the high fidelity processing flow of three-dimensional data in Chunguang exploration area has been improved,and a series of prestack relative amplitude preservation and denoising techniques,high precision amplitude preservation techniques,well constraint resolution enhancement techniques and corresponding relative fidelity evaluation techniques have been formed.Through the application of these techniques and methods,the signal-to-noise ratio of the main target layer of Shawan Formation is more than 6 and the main frequency is more than 80 Hz,which meets the resolution requirement of seismic data of subdivision layers on the premise of fidelity.The implementation of this paper improves the signal-to-noise ratio,resolution and fidelity of three-dimensional seismic data of Shawan Formation,and is more conducive to the search for lithologic traps.Combining with seismic and geological data,a number of traps were finally found and implemented,and a number of wells were suggested,which showed that the fidelity of the data was good and could meet the needs of interpretation and comprehensive research.