Research On Pulse Neutron Spectroscopy Logging Interpretation Method

Due to the various reservoir lithology,complicated mineral components,strong heterogeneity and in the process of oil extraction process using water flooding technology led to water mineralization of the formation is difficult to determine in YX oilfield,the neutron lifetime logging is not suitable in the area.In order to effectively monitor the residual oil saturation of the formation,find the potential layer and improve the oil and gas recovery rate,YX oil field introduced the pulsed neutron energy spectrum saturation instrument(PSSL).The instrument integrates the carbon oxygen ratio spectrum logging and neutron lifetime logging,which is not limited by the mineralization and can measure the rich formation information.The establishment of a regional interpretation model is conducive to improving the residual oil saturation interpretation accuracy.In the second chapter,the principle of PSSL logging is analyzed,the inelastic scattering measurement mode and trapping measurement mode of PSSL are introduced.The effects of lithology,porosity,borehole environment and well logging on the logging response of the inelastic scattering measurement model are analyzed in detail.In the third chapter,the method of calculating and analyzing the logging data of PSSL inelastic scattering measurement is studied.The method of calculating the mud content,porosity and oil saturation by using PSSL logging data is put forward.Based on the physical volume model of rock,the carbon-oxygen ratio residual oil saturation interpretation model and the trapping measurement model residual oil saturation interpretation model are established,as well as a correction method is proposed for the influence of lithology and logging on logging data.In the fourth chapter,through the processing of two wells with PSSL data,the feasibility and correctness of the above method are verified,and the coincidence rate is higher.The results show that the PSSL logging instrument is rich in measuring mode and can be used in the calculation of shale content,porosity and oil saturation.The inelastic scattering measurement model of PSSL logging is affected by lithology,porosity,borehole environment and well logging.In the process of PSSL logging data,the effects of mud,calcareous,zero drift and so on can be improved to improve the interpretation accuracy.Based on the physical volume model of rock and combined with the undeveloped reservoir completion data and PSSL logging data in this area,the oil saturation interpretation model has overcome the problem of data without scale wells,the application effect is good,the regional applicability is strong.