Optimization Method Study Of Enhanced Oil Recovery For Conventional Heavy Oil Reservoir

Heavy oil reserves were abundant in china and the effective and economicaldevelopment of heavy oil reserves could relieve the energy resource stress. Tertiary oilrecovery techniques were one of the chief technologies of heavy oil development. Potentialanalysis of tertiary oil recovery techniques was essentially important because of thecomplicated mechanism, large investment, high cost and risk of the methodsThe mechanism and application of present tertiary oil recovery techniques werecomprehensively investigated and studied with the combination of the tendency of tertiary oilrecovery techniques. Taken conventional heavy oil reservoir of Nanpu block in Jidong oilfieldas example, initial screening of tertiary oil production methods was conducted with thecombination of geological and development conditions on the basis of investigation of staticand dynamic data of 364 tertiary production blocks at home and abroad. It was indicated thatchemical flooding, compound foam flooding and microbial flooding were suitable for shallowhigh permeability heavy oil reservoirs.Tertiary oil recovery technique selection was performed in conventional heavy oilreservoir of Nanpu block in Jidong oilfield with the combination of reservoir simulation andeconomic evaluation. The results showed that crosslinked polymer flooding was suitable forshallow conventional heavy oil reservoirs and laboratory experiment also verified the validityof the technology. The influential factors analytical results of technological development andeconomic effect in crosslinked polymer flooding indicated that the chief reservoir influentialfactors included variation coefficient of permeability, formation water salinity andtemperature, oil viscosity and permeability and economic benefit was mainly influenced byoil price and incremental investment.On the basis of reservoir simulation technique and economic evaluation method with thecombination of Monte Carlo principle, adaptability analysis and potential evaluation methodwas developed with the risk evaluation indexes of enhancing oil recovery and internal returnof rate. Then risk analysis and potential evaluation were performed in shallow conventionalheavy oil reservoir of Nanpu block in Jidong oilfield. After crosslinked polymer flooding, this type of reservoir could enhance oil recovery by3.47～3.87%, increase recoverable reserves by35.22～39.28×104t, the internal return of rate after tax was 23.66～64.71% and risk indexwas 4.17%, which indicated large technological and economic potential and low risk.The adaptability and potential evaluation method of various tertiary oil recoverytechniques could comprehensively consider the technology, economic adaptability and risk oftertiary oil recovery techniques and provide guideline for field development.