Analysis and suggestion of seismic data acquisition parameters in gas cloud area based on geometry degradation
Shallow gas clouds are widely developed in Bohai Bay.The seismic profiles of areas affected by gas cloud are mostly shown as fuzzy zones,so it is difficult to describe the characteristics of the structure and reser-voir accurately.However,there is less academic research on the seismic acquisition of gas cloud area.There-fore,based on the three sets of seismic data with big differences in key acquisition parameters successively ac-quired in X oilfield of Bohai Bay,this paper performed degradation treatment on the actual geometry and studied the influence of a single acquisition parameter on the seismic imaging of gas cloud area,including acqui-sition direction,bin size,and fold,on the premise that other acquisition parameters are consistent.Finally,the paper obtained three conclusions that could guide seismic acquisition designs of offshore gas cloud areas.① The imaging of banded gas clouds is greatly affected by acquisition direction,and the imaging quality inside gas cloud is relatively better when the acquisition is performed along the short axis of gas clouds.The plane influence range of gas cloud is relatively smaller when the acquisition is performed along the long axis of gas cloud.It is suggested that the shape of gas clouds should be fully considered in seismic acquisition.In addi-tion,bidirectional acquisition and fusion processing should be used to improve the imaging of gas cloud areas for banded gas clouds with obvious directional characteristics.② The differences in imaging quality of gas cloud areas and plane influence range of gas cloud under different bin sizes are small,and the reduction of bin size contributes little to the imaging of gas cloud areas.It is suggested that conventional bin size should be adopted in seismic acquisition of gas cloud areas,instead of emphasizing small bin size.③ After reaching a cer-tain number of folds,the increase of fold contributes little to the imaging of area not affected by gas cloud,while it is still significant to the imaging of gas cloud areas.It is suggested to increase the effective fold in seis-mic acquisition of gas cloud area.
gas cloud areageometry degradationacquisition directionbin sizefold
万方数据
维普
