Polymer Flooding Reservoir Fine Description And Comprehensive Adjustment In Offshore Unconsolidated Sandstone Oilfield

SZ36-1 oilfield is a typical unconsolidated sandstone oilfield,after more than 10 years polymer industrial production,development technology is increasingly mature and matching,the polymer injection is started in the research area in 2010.However,after the polymer injection,the problems of the liquid volume decreasing and the injection-production well network changing occurred,the effect was not expected,and the polymer inefficient circulation was serious.At the same time,the index of oil production and increase per ton polymer declines year by year,it cannot meet the mining demand of low cost and high benefit,therefore,a new round of loose sandstone fine reservoir description and quantitative-qualitative remaining oil analysis is necessary to be carried out,comprehensive adjustment measures are given,providing research basis for oilfield continuous production.Through the theoretical analysis,indoor experiment and well seismic fine reservoir description,the paper summarizes and analyzes the development effect of the polymer flooding at the present stage,finds out the focus of the development and governance of the polymer flooding,carries out the fine geological research,combines the reservoir numerical simulation,and uses the method of dynamic and static combination to describe the residual oil from the macroscopic to the micro scale,provides the most timely and effective personalized adjustment and tapping potential guidance for oilfield polymer flooding.Through stratigraphic division and contrast,fine interpretation,seismic inversion and deposition,the paper subdivides the layers into small layers,redescription the characteristics of micro structure and fault development,and further summarizes the reservoir spatial distribution pattern.In view of the distribution characteristics of the polymer flooding reservoir dominant percolation channel,this paper uses laboratory analysis and the method of theoretical research combining dynamic production data statistics,reveals the reservoir physical change characteristics under the influence of polymer flooding,and gives a quantitative evaluation method,and summarizes the distribution characteristics of the dominant percolation channel.In this paper,a double controlled three-dimensional geological modeling method based on inversion control and phase control is proposed.Using acoustic curve as a bridge,the "soft constraint" of wave impedance inversion and the "hard constraint" of microphase data are used to complete the establishment of the joint property model of the well earthquake in the study area.The study shows that the geological model not only realizes the interwell prediction,but also has high precision.On this basis,the reservoir numerical model is established by combining the dynamic data of the oilfield.In the field of residual oil distribution,this paper describes the distribution characteristics of residual oil from macro to micro scale according to the laboratory experiment and reservoir numerical simulation results and using the method of dynamic and static combination.The remaining oil is mainly composed of cluster,oil film,blind ends and columnar remaining oil,and macro remaining oil mainly develops in 8 types.Considering that the remaining oil is affected by geological factors and development factors,a method of remaining oil evaluation based on grey relational fuzzy mathematics is established in this paper.Based on grey relational theory,the quantitative evaluation of remaining oil is completed.Furthermore,fuzzy mathematics analysis method is applied to evaluate the main controlling factors of remaining oil in oil group.Based on the different types of remaining oil distribution pattern,this paper carries out the study of comprehensive adjustment methods and measures,and analyzes the remaining oil digging measures,such as stratified water injection,profile control,water plugging,hole filling,injection production strength and well network encryption,comprehensive evaluation of the potential effect of different types of remaining oil,and summers up the countermeasures of remaining oil potential digging and compiles a comprehensive adjustment scheme.