Dynamic Monitoring Method Research Of Interwell Multi-stage Chemical Tracer Between Oil And Water Wells

As an important object to replace C hina’s oil-gas,the most important development of the fractured low permeability reservoir is water-flooding.However,due to the tight matrix and complex fracture network,the heterogeneity of reservoir and water channeling of wells are very serious.In order to plug the high permeability zone and improve the sweep efficiency and comprehensive utilization of injected water,various regulations emerge in endlessly.Because that seepage characteristics after water flooding are not understood in the fractured low permeability reservoir,the effect of regulation is often less than satisfactory.Therefore,based on strong quantification,good accuracy,high maturity,wide applicability of interwell tracer,interwell multistep tracer monitoring technology is put forward to realize the real-time monitoring and adjustment and improve the effect of regulation.Taking SH oilfield for example,according to characteristics of sedimentation,reservoir,fracture and water-flooding development,the reason of water channeling in the fractured low permeability reservoir is analyzed.Meanwhile,the adaptive analysis of step-by-step regulation and interwell multistep tracer supporting system are in progress.Based on interwe ll chemical tracer,filtered principles of interwell chemical tracer material in the step-by-step regulation are improved.Design methods of steps and computational formula of tracer dosage in every steps are raised.The next peak time can be predicted to design and adjust the sampling period of tracer monitoring via result of tracer material explanation from the former step.At the same time,interpretative principles of interwell multistep chemical tracer are discussed.Calculation methods of injected water distribution coefficient,fractured swept volume and simulation parameters in tracer model are introduced.The method to evaluate heterogeneity of main interpretative parameters and the optimization and prediction of parameters in the step-by-step regulation are researched and proposed.Finally,the system of interwell multistep chemical tracer technology is formed.Field tests show that the interwell multistep chemical tracer technology has good adaptability.There are good maneuverability and high accuracy in the process of tracer filtration,step design,dosage calculation and prediction of parameters optimization in the step-by-step regulation.The dynamic variation rule of main reservoir parameters show that it has good effect under regulation in the study well group,and heterogeneity of reservoir is improved obviously.Research shows that the interwell multistep chemical tracer technology can provide important basis for real-time optimization of parameters and prediction of result in the step-by-step regulation in fractured low permeability reservoir.