The Application Study Of Prestack Seismic Attribution Analysis In One Well Field

The Tarim Basin is one of the largest petroliferous basins in China, which has great potential of oil and gas resources. In the Tarim basin has been discovered several sets of oil reservoirs and a number of oil-gas fields,so it is regarded as an important replace base of the energy strategy of China.But in the Bamai area of Tarim basin,the Ordovician fractured-vuggy reservoir buried depth and with complex types,which at the same time developed small-scaled fractured-vuggy space, so it has the characteristics of low porosity and low permeability.The application of conventional poststack seismic technology will not satisfy the reservoir prediction in details,so this thesis will describe the application study of prestack seismic attribution in YB1well field.Prestack seismic technology based on AVO method as same as poststack seismic technology,but the former takes use of more information of seismic gathers,so wins high favour because of higher accuracy.But the prestack seismic technology requires high quality of prestack seismic data volume,and the processing procedure not only complex,but also very difficult.The thesis processes on the real data at first in oder to make the result of integrated reservior prediction reliable.The procedure includes log correction after the standardization and consistency Analysis,and then calculate shear wave velocity based on Xu-White model which is suitable for carbonate rock area.We use super gather, random noise and multiple wave suppression technology to improve the signa-to-noise ratio.Then analysis the AVO response characteristics of the real well logs,fine out the sensitive parameters of the reservoir.For the prestack seismic technology,this thesis goes on with prestack elastic impedance inversion which separatly for near,middle and far angle gather,prestack AVO simultaneous inversion and LMR inversion to predict reservoir.With the fine processing of prestack seismic data,the thesis gets the goal of reservior prediction in details,summarized as follows:(1) The analysis of prestack seismic attribution shows that the negative gradient and the positive intercept is consistent with the class one reservoirs which explain as the well logs. The scaled poisson change shows the fluid development interval Yingshan formation.(2) The result of El inversion with different angle gathers shows the near angle gather is the most optimum for reservior prediction.lt displays the fluid developing at the base of YBl,the upper of YBl-2x and Penglai Ba formation.(3) The result of prestack AVO simultaneous inversion and LMR inversion shows the same reservior character with El inversion,but it also shows more details,specially the LMR inversion result and some elastic parameters ensure the fluid developing between the YB1and YB1-2x at the upper location of Yingshan formation.(4) With the application study of prestack seismic attribution to predict reservior,the thesis selects out scaled poisson change, El of near angle gather, λp, μp,bulk modulus and Young’s modulus as the optimum sensitive parameters for reservoir prediction.