Experimental on Enhanced Oil Recovery by Hydrocarbon Gas Miscible Flooding after Volume Fracturing in Mahu Conglomerate Reservoir
In Mahu tight conglomerate reservoir in Xinjiang,the technology of hydrocarbon gas flooding was adopted to greatly en-hance oil recovery.Faced with the large-scale development of horizontal well volume fracturing,hydraulic pressure fracture NetEase formed gas channelling channel under small well spacing,which affected the sweep volume of gas flooding.In order to study the impact of horizontal well patterns after fracturing on the development effect of hydrocarbon gas drive,a model of artificial fracture +matrix in-jection hydrocarbon gas drive in Mahu tight conglomerate oil reservoir was proposed for the first time.Based on this model,an experi-mental model was designed,and gas drive experiments were conducted using full diameter core models with different splicing ratios for fracturing and non fracturing,clarifying the relationship between fracturing and matrix.The results show that the core recovery by hydro-carbon gas flooding can reach 38.26%.The higher the fracture ratio of full-diameter core is,the lower the recovery rate is.Small-scale fracturing allows for smoother oil recovery and higher recovery.After hydrocarbon gas flooding,the recovery degree can be further in-creased by 7.1%through huff and puff.This experiment can provide a practical guiding basis for field test of fracturing scale,reasona-ble well spacing and gas injection rate of horizontal Wells in hydrocarbon gas flooding.