Seismic Data Acquisition Technology Application And Research On The South Oman Salt Basin

Oman is one of the major oil producing countries in the Middle East.The surface condition is varied from three types in Oman,such as Gravel plain,desert area and mountain area.Oil and gas reservoirs in Salt Basin are the main reservoirs in Oman.The Salt Basins are Fahud Salt Basin in north area,Ghaba Salt Basin in middle area and South Oman Salt Basin.With the development of seismic acquisition techniques,2D seismic data acquisition developed from low full fold and long receiver interval distance to short receiver/source interval distance,and 3D seismic data acquisition is currently operated with wide band,wide azimuth,and high density is widely used in recently year.Vibrator source has the advantages of safety and environmental protection and widely used in in Oman.With the development of vibrator hardware and software of instrument,the new method of DSSS(Distance Separated Slip Sweep)is developed and applied in current high density 3D with high productivity which can reduce cost for oil company,also low frequency vibrators with related techniques can be used in seismic acquisition,which strengthen the energy and improve the efficiency of low frequency signal transmission.It is good for low quality complex inverse fault structure zone with extended the band width and improved data quality.The sweep band width with 1.5Hz to 86 Hz is typically used in this area.After expanding the traditional effective frequency band to the low frequency,the ratio for seismic data is better improved and the vertical resolution is increased,and finally the imaging quality of deep geological targets is also improved.This paper studies the geology structures,the acquired geometries in Oman and the vibrator technologies currently used during data acquisition.The factors of limiting the data quality on the complex salt basin is understood by analyzing the underground geology and surface condition.The method for designing low frequency sweep signal is presented by extending the sweep time on the low frequency part,and for minimizing the distortion of low frequency,measures of optimizing sweep signal design are proposed,the suitable geometry is proposed with enough spread length and fold for the deep target,and finally the data acquisition technology is recommended in this area with suitable source method.The following comparison tests including vibrator sweep parameters test,low frequency custom signal test,distortion test on saline land and multiple sweeps test for strong wind noise were conducted and measures for high frequency distortion suppression and wind noise were proposed in this paper as results.The optimal survey parameters are used in field operation based on tests to ensure the quality of seismic data acquisition and a series of technologies is proposed for seismic data acquisition on the salt basin in South Oman.