Effect Analysis And Process Parameter Optimization Of Compound Stimulation In Thin Heavy Oil Reservoir

The effect of steam stimulation is poor for Chen373in Shengli oilfield. In order toimprove production efficiency, development approach is changed. The feasibility of Thechemical soaking, CO2soaking and compound soaking is studied. Laboratory test wasconducted to analyze the effects of chemicals, carbon dioxide and nitrogen on the heavy oil ofChen373. The experiment results show that the chemical can reduce the viscosity of heavyoil significantly and the interfacial tension of oil-water. CO2and N2can dissolve in the heavyoil under certain pressure and certain temperature conditions, which can reduce the viscosityof heavy oil. The viscosity reduction of heavy oil increase and the oil volume factor increaseslinearly as the solution gas-oil ratio increasing. When chemical and gas are combined, theviscosity is reduced even larger than only using chemical and gas. production effect of threewell groups, chen371-6, chen311and chen36-X76, were analyzed by numerical reservoirsimulation. It indicted that the production of compound stimulation was good. The productioneffect of the three wells became bad and the output-input ratio was lower than1after seven oreight steam stimulation cycles. If compound stimulation is done in right time, the decline rateof cycle oil production is decreased and the production cycle increase. The right time forchen371-6, chen311and chen36-X76respectively is fifth cycle, forth cycle and seventh cycle.Periodic oil production of CO2-chemical compound stimulation is more than that ofN2-chemical compound stimulation. Above all, chemical-CO2compound and chemical-N2compound is adapted to the thin heavy oil reservoir in chen373block.