Crosswell Seismic P Wave Extracting And Reflect Wave Imaging

Nowdays seismic exploration technique enters the development stage of oilfiled fromoilfield prospecting stage, this gives rise to quick development of crosswell seismic tehcnique.How to get effective reflect wave from complex crosswell seismic record and crosswellseismic imaging are hot research point of crosswell seismic data processing. The acquisitionof 3C crosswell seismic, the separation of P and S waves, P waves component extracting, andwave equation imaging methods are all very important for crosswell seismic data processing.Based on principle of high resolution frequency domain radon transform, forward andinverse transform of high resolution Radon transform are studied and designed according tothe characters of crosswell data such as: high sample rate, wide spectrum, high mainfrequency and large single shot data quantity. Corresponding processing program aredeveloped and various parameters are tested and adjusted. Considering the specific feature ofcrosswell seismic acquisition system and the difference of P and S wave in polar nature, weutilize high resolution forward/inverse radon transform to develop the P/S wavefieldseparation method in? ? p domain, and design corresponding program. Processing ofsimulated data of theoretical model and practical crosswell model separates P/S wavefieldsuccessfully.In the basis of extracting P wavefield, depending on data structure of existing crosswellseismic processing system, we transplant wave equation finite-difference migration methodinto crosswell seismic data processing. Considering the character of crosswell seismic, wegrid the crosswell section, calculate imaging time by ray-tracing, use finite-difference methodto achieve crosswell wavefield reverse time continuation, and finally apply imaging conditionto get finite-difference reverse-time migration profile.Processing results implies that: imaging from extracted P wavefiled can reflect actualattitude of strata more clearly than image from full P/S wavefield, the imaging results havehigh resolution and high S/N.