Physical Simulation Experimental Study On Three-dimensional Cores Of Huff-puff Energy Increasing Technology Of Fracture Network Wells

The Fuyu oil layer in the South Putaohua Oilfield has the characteristics of low porosity and permeability,in the early process of development,the fracture network fracturing technology was carried out.With the extension of production time,the formation energy consumption became larger,which cannot be effectively supplemented,what's more,the production decline is faster,and the recovery degree is low,which restricts and affects the development effect and economic benefit seriously.Therefore,it is necessary to find out the technical measures for further tapping the potential of the reservoir and improving the oil recovery.Considering that the porosity of Fuyu reservoir is small,the permeability is low and there is a strong capillary force,which cannot supplement the formation energy effectively,therefore,it has the potential of improving the oil recovery by imbibition.The results show that with the increase of reservoir pressure,the oil recovery of CY surfactant increases.With the increase of injection velocity,the imbibition recovery rate showed a trend of "increasing first and then decreasing".With the increase of injection slug size,the imbibition recovery rate increases,but the amplification decreases.With the pressure holding time increasing,the imbibition recovery rate increases,but the amplification decreases gradually.With the number of alternating injection increasing the imbibition recovery rate increases,but the amplification decreases gradually.With the increase of the length of main seam and the number of branch joints,the imbibition recovery rate increases,but the amplification decreases gradually.With the increase of "potentiator + infiltration fluid" carried out,the water content increases,and oil recovery amplification decreases gradually.With the increase of the amount of energy and the imbibition time,the oil recovery amplification increases gradually,but extent decreases gradually.With the increase of injection velocity and slug size,the oil recovery amplification increased first and then decreased.According to the actual demand of the oilfield,aiming at improving the imbibition recovery by the authigenic CO2 huff-puff energy increasing technology and the optimization of liquid permeability performance,theoretically guided by oilfield chemistry,reservoir physics and colloid surface chemistry,taking chemical analysis,instrument testing and physical simulation as the technical means,taking Fuyu oil layer in South Putaohua Oilfield as the research platform,From the study of the properities of reservoir rocks and fluid,performance evaluation of energy increasing technology system,selection and performance evaluation of liquid permeability system,making process of artificial cores,the study of imbibition effects and influence factors of fractured rock,the imbibition effects and influence factors of fracture parameters of network fracturing simulation model.This paper carried out physical simulation experiments of three-dimensional cores huff-puff energy increasing technology of fracture network wells.