3d RVSP Wave Field Analysis And Multiple Wave Suppression In Coal Field

VSP seismic exploration technology has been widely used in oil and gas exploration,which provides strong support for reservoir prediction and description(fine structure characteristics,lithology,porosity,anisotropy,formation elastic parameters,etc.).The popularization and application of VSP well are affected by the high cost of receiving equipment,less receiving channels,more ground firing points and high engineering cost.RVSP(reverse vertical seismic profile)adopts the observation system of borehole excitation and surface reception,and the number of acquisition channels can reach tens of thousands.It has the same exploration effect as VSP.For solid deposits,after sampling and testing,the exploration boreholes are sealed.Therefore,the exploration hole and RVSP technology can greatly reduce the construction cost and have broad application prospects.Aiming at the RVSP exploration method,this paper analyzes the wave field characteristics of multiple waves under the condition of multiple coal seams,and studies the method of suppressing multiple reflected waves.The imaging range of RVSP is extended by using virtual source imaging,wave field reconstruction and migration imaging processing.The main research is as follows:(1)The virtual source RVSP multiple wave imaging method is studied,which expands the imaging range of the original seismic wave field and avoids the influence of surface fluctuation and lateral velocity change.(2)The method of multiple recognition and suppression is studied by numerical simulation.According to the characteristics of RVSP itself,the characteristics of upper and lower wave fields are used to identify and suppress RVSP multiple.(3)RVSP deconvolution method is studied to further suppress multiple waves and improve imaging resolution;(4)The actual data are processed,multiple waves are suppressed,and the migration imaging results are analyzed.Through numerical simulation and actual data processing,the imaging range of multiple wave suppression and imaging technology for RVSP is enlarged,and the imaging accuracy of reflected wave in main target layer is improved.