Study Of Reservoir Seismic Prediction In Production Area With Dense Wells Of Daqing Changyuan Oilfield

In this paper, focusing on geological requirements of dense wells of Daqing Changyuan Oilfield development area, on the bases of different log information correction, curve reconfiguration and seismic petrophysical analysis, research seismic attribute analysis technique to predict characteristics of thick bed sand body of crosswells, research the horizontal change of cross-well thin sands with dense wells broadband constrained seismic inversion. This technique improve reservoir forecast accuracy, and provide new thinking for maturing field in fine description of reservoir. The research effort has been applied to the optimization of La5-Ping221 horizontal well design in Lamadian Oilfield, in the case of wells drilled sandbody 94.6%.1 Studied by log correction give priority to double standard trend surface layer, removed the logging environment and logging device caused by random errors and system errors. It provided safegrard for petrophysical analysis seismic and make well match seismic.2 S-wave prediction means of continental facies mid-porosity sand/mudstone has been established by the application of petrophysical analysis of Greenberg-Castagna S-wave prediction model, achieving a S-wave prediction of Lamadian Oilfield. By the two wells to verify the measured S-wave and predicted S-wave correlation coefficient was more than 0.95, which laid the foundation for the pre-stack seismic attribute analysis and elastic inversion work.3 Seismic rock elastic parameters functional relationship which are in different lithology, porosity and oil saturation condition of oil layer, oil layer group and member, has established , respectively. And analysed the change between acoustic impedance and oil saturation.The results show that acoustic impedance, Poisson’s ratio and the rate of P-wave increased significantly, based on crossplot of the acoustic impedance vs Poisson’s ratio, crossplot of P-wave vs S-wave, when oil saturation increased from 0% to 50%, and when oil saturation between 50%~80%, acoustic impedance, Poisson’s ratio, and the rate of P-wave are in smooth.4 The study area in different oil saturation conditions, the synthetic seismogram of the oil layer group took place obvious changes. To SaⅡand the lower reservoir, the energy of amplitude gradually increased with the oil saturation increases, and phase slightly to the downward, above the oil layer group SaⅡ, with the increasing oil saturation, the energy of amplitude of did not change obviously.5 Owing to Fuzzy Neural Network technology of seismic attribute analysis, forecasted the horizontal change of thick bed sands, consummated deposition microfacies belt figure, having improved recognition of types of the channel sand body.6 Based on accoustic travel time curve reconstruction, infill resampling and the space variant wavelet, with sequence Gauss allocation common simulation and simulated annealing broadband constrained inversion means and so on, achieved a dense wells under the conditions of high resolution seismic inversion and layer sand body forecast among wells, verified coincidence rate sand layer of 20 posterior-wells had been reached 90%.7 Results of research in the field to optimize Lamadian Oilfield La 5-Ping 221 horizontal track arrangement, and Reservoir Geophysics becomes an important technique in the design of horizontal wells of Changyuan Oilfield.