Classification And Evaluation Of Typical Hard-to-recover Reserves In The Peripheral Oil Fields Of Daqing

Since the introduction of the unconventional oil and gas theory,the study of difficult reserves has entered an era of rapid development.How to maximize the economic benefits and achieve the optimization of sustainable development while maintaining low cost.Responding to the increasing world oil and gas demand and the gradual shortage of conventional oil and gas resources has become one of the important tasks of the current oil and gas exploration and development industry.This thesis is based on the research project of "Evaluation Parameters for the Benefits of Blocks with Difficult Recovery" undertaken by the Daqing Oilfield Co,Ltd.Based on 106 typical hard-to-recover blocks in 14 oilfields in Daqing,the study was conducted.After understanding the geological characteristics and development status of typical difficult-to-recover reserves in Daqing Oilfield,by analyzing the reservoir geological characteristics and development characteristics,firstly,the cumulative probability method is used to establish a single factor classification boundary for the sample points of the target block,and the cumulative probability map is drawn.To determine the single-factor classification results.In order to solve the cross problem of single factor classification.The cluster analysis method is selected,and the parameters that can represent the reservoir characteristics and development characteristics are selected according to the affinity relationship between the parameters,and then the gray correlation analysis and the cumulative probability method are adopted.At the same time,a multi-factor comprehensive classification,dynamic and static comprehensive classification evaluation system will be established,and the relationship between the dynamic and static evaluation results of the developed blocks will be used to predict the dynamic development benefits of the undeveloped blocks.Finally,combining the actual development characteristics of the Daqing hard-to-recover reserves block and the current domestic and international economic evaluation research progress,the economic limit method is used for the currently developed blocks,and the cash flow method is used to calculate the economic benefits of the hard-to-recover blocks.Then,the multiple regression method is used to establish a quantitative prediction model between the economic benefit evaluation parameters and static parameters of the difficult-to-recover reserves.Then,the multiple regression method is used to establish a quantitative prediction model between the economic benefit evaluation parameters and static parameters of the difficult-to-recover reserves.Through the above research work,the blocks of hard-to-recoverreserves around Daqing are finally divided into three categories.The results of static,dynamic,dynamic and static parameters combined with classification evaluation have good consistency.Through the above research work,it is determined that the results of static,dynamic,dynamic and static parameters combined with classification evaluation have good consistency,and Daqing difficult-to-recover reserves blocks are divided into three categories.Routine profitable reserves are Class I;de-allocation,extended evaluation period,and investment reduction are classified as Class II;conventional,de-allocated,extended evaluation period,and investment reduction are not classified as Class III.Combining the geological and development characteristics of the Daqing difficult-to-recover reserves block,the characteristics of sand bodies suitable for development in vertical wells,horizontal wells and vertical wells + horizontal wells were determined respectively.The purpose of applying the characteristic parameters of hard-to-recover reserves is to predict the economic and effective utilization status,guide the economic and effective development,and provide the geological basis for the development planning of hard-to-recover reserves.