Due to the characteristics of reservoir formation,the producing level of low permeability reservoir is relatively very low.It is hard to obtain high recovery through conventional development schemes.Considering the ti...Due to the characteristics of reservoir formation,the producing level of low permeability reservoir is relatively very low.It is hard to obtain high recovery through conventional development schemes.Considering the tight matrix,complex fracture system,low production level of producers,and low recovery factor ofMblock in Xinjiang oilfield,it is selected for on-site pilot test of nitrogen foam flooding.Detailed flooding scheme is made and the test results are evaluated respectively both for producers and injectors.The pressure index,filling degree,and fluid injection profile are found to be all improved in injectors after injection of nitrogen foam.The oil production,water cut and liquid production file are also improved in most of the producers,with the natural decline rate in the test area become slow.Results show that nitrogen foam flooding technology can be good technical storage for enhanced oil recovery in low permeability reservoir.展开更多
CO_(2) is the main source of greenhouse emission,and the environment problem caused by greenhouse effect has drawn worldwide attention.In most oilfields in China,a method of waterflooding is usually used to enhance oi...CO_(2) is the main source of greenhouse emission,and the environment problem caused by greenhouse effect has drawn worldwide attention.In most oilfields in China,a method of waterflooding is usually used to enhance oil recovery,which is favorable to carry out CO_(2) injection study.The CO_(2) injection in the water-flooded oilfields can not only store CO_(2),but also enhance the oil recovery.In this article,the coreflooding tests with refined oil were conducted to investigate CO_(2) displacement characteristic in watersaturated formation under different injection rate and water-flooded oil reservoir under different formation pressure and oil saturation,then the CO_(2) storage capacity was calculated.The testing result shows that the displacement efficiency increases with the rise of the CO_(2) injection rate,and the CO_(2) injection can enhance the oil recovery about 15%OOIP under the experimental condition.When injecting CO_(2) after the waterflooding,the CO_(2) storage capacity increases as the rise of the formation pressure.The core-flooding tests also indicate that when the initial oil saturation of reservoir prior CO_(2) injection is higher,the oil recovery will be higher when injecting the same pore volume(PV)of CO_(2),and the CO_(2) storage capacity will be larger.展开更多
基金supported by the Prospective and Fundamental Project of CNPC“Study on the EOR Technology by Foam Flooding(2021DJ1603)”by Open Fund of State Key Laboratory of Enhanced Oil Recovery,CNPC(2022-KFKT-29).
文摘Due to the characteristics of reservoir formation,the producing level of low permeability reservoir is relatively very low.It is hard to obtain high recovery through conventional development schemes.Considering the tight matrix,complex fracture system,low production level of producers,and low recovery factor ofMblock in Xinjiang oilfield,it is selected for on-site pilot test of nitrogen foam flooding.Detailed flooding scheme is made and the test results are evaluated respectively both for producers and injectors.The pressure index,filling degree,and fluid injection profile are found to be all improved in injectors after injection of nitrogen foam.The oil production,water cut and liquid production file are also improved in most of the producers,with the natural decline rate in the test area become slow.Results show that nitrogen foam flooding technology can be good technical storage for enhanced oil recovery in low permeability reservoir.
基金supported by the National Basic Research Pro-gramof China(973 Program)(2011CB707300)National Science and Technology Major Project of China(2017ZX05070002).
文摘CO_(2) is the main source of greenhouse emission,and the environment problem caused by greenhouse effect has drawn worldwide attention.In most oilfields in China,a method of waterflooding is usually used to enhance oil recovery,which is favorable to carry out CO_(2) injection study.The CO_(2) injection in the water-flooded oilfields can not only store CO_(2),but also enhance the oil recovery.In this article,the coreflooding tests with refined oil were conducted to investigate CO_(2) displacement characteristic in watersaturated formation under different injection rate and water-flooded oil reservoir under different formation pressure and oil saturation,then the CO_(2) storage capacity was calculated.The testing result shows that the displacement efficiency increases with the rise of the CO_(2) injection rate,and the CO_(2) injection can enhance the oil recovery about 15%OOIP under the experimental condition.When injecting CO_(2) after the waterflooding,the CO_(2) storage capacity increases as the rise of the formation pressure.The core-flooding tests also indicate that when the initial oil saturation of reservoir prior CO_(2) injection is higher,the oil recovery will be higher when injecting the same pore volume(PV)of CO_(2),and the CO_(2) storage capacity will be larger.
