The Key Technology Of Seismic Imaging In The Tugulu-Manas Area In The Southern Part Of Junggar

The southern margin of Junggar basin is characterized with numerous traps,favorable hydrocarbon accumulation conditions,and substantial exploration potential,but the seismic imaging effect of seismic data main body structure is poor and,the interpretation project is of multiplicity,so it is difficult to identify shape of traps and distribution of fracture systems of each strata.For land seismic data,whether or not the imaging results agree with geological interpretation and research demand will be determined by seismic data preprocessing and velocity model.The final image effect depends to the quality of seismic data preprocessing and the accuracy and rationality of prestack migration imaging velocity estimating.By studying on prestack imaging technology of Tugulu-Manasi area of the southern margin,Junggar Basin,using the statics correction technology of first breaks fitting,the near surface structure model is exactly built,the puzzle of statics correction is effectively solved in this area,the quality of imaging is apparently improved,and structure can be well interpreted;by studying on prestack noise suppression technology,the middle-low frequency information of gathers is retained,combined with the technology of improving signal-to-noise ratio of multi-domain space,the quality of imaging is significantly improved in Tugulu-Manasi area;by studying on the method of structure model-restricted well control modeling,the technique sequence of velocity modeling has been generated under the condition of low signal-to-noise ratio:firstly,establishing interval velocity template with regional drilling data,and eliminating the influence of near-surface western regions conglomerate on underlying strata velocity;secondly,after correcting seismic velocity constrained by logging velocity data,using the method of interval velocity inversion,such as horizon coherent inversion,etc.to improve the precision of velocity model;finally,building velocity model similar to 3D based on 2D grid to ensure the closed of space and time in two-dimensional grid velocity field,so a good imaging results have been achieved during prestack depth migration.Through research and application of these technology,the quality of seismic reflection imaging has been improved in the area of TuGuLu-Manasi of the southern margin,Junggar basin,and basic data assistance has been offered for exact identification trap and its height and petroleum exploration research.