The Study Of High Resolution Seismic Acquisition Method In Block Baiqiu Of Nanyang Depression

Nanyang depression is a secondary depression of Nanxiang Basin,which closely neighbours the west of Biyang depression.It is one of the key areas of Henan oilfield to increase petroleum reserve volume.Baiqiu block is located in the north part of Nanyang depression,which is a directive area of hydrocarbon migration.In this paper,a research aiming at increasing seismic data resolution of Baiqiu block was carried out.According to demand of geologic task,studying on geological model demonstration,recording geometry optimization,shooting and receiving technique, a set of acquisition methods suit for this area were gained.In performing acquisition method demonstration,firstly geologic research was closely contacted with acquisition method,through intensive cooperation with geologists,valid geological model was built,which provide favourable foundation for further acquisition method demonstration;secondly advanced softwares(Green Mountain,Klesis)were used in demonstrating geological model,also static correction coupling and velocity analysis were fully considered in designing recording geometry,which made acquisition data adaptable for sequent processing.Combining these with the development of recording geometry design method at home and abroad,recording geometry in this block was optimized from aspects of acquisition binning,characteristics of main target layers'depth changing, folds in vertical and horizontal direction,noise suppression,etc..Theoretical research was done in effect of shooting depth and charge size on resolution.Through analysis of ghosting interface,seismic wavelets and burst radius, combination of field shooting elements and surface layer investigation,optimum shooting depth was determined.Through combination of theoretical research on charge size with comparision results of different charge size in field tests,optimum charge size was determined.In addition, selection of dynamite type should satisfy impedance matching principle.Different type of dynamite was analyzed and one suit for this block was choosed.In receiving aspect,through theoretical research on geophone array, receiving response of different geophones,analyzing effects of different array length, geophone spacing and different geophone type on resolution in field tests,the geophone array mode and geophone type suit for this block were determined.The quality of seismic section in the area is improved greatly, and the anticipated geological tasks are accomplished with the seismic parameters.