Project For Reclaim Of All Gaseous Substances From Boiler Flue Gas For Oil Recovery

When the reservoirs belong to continental sediments, the heterogeneity is quite serious,the viscosity of part of the crude oil is very high and the water-cut rising fast. Plus someoilfields have entered into the mid-to late development stage, although we take a series ofmeasures such as the water injection and steam injection, the oil recovery is still relatively low,the mining cost is higher and a lot of geological reserves is difficult to or even cannot beexploited economically. The oil recovery rate of low permeability, heavy oil and condensatereservoir is lower while the cost is higher. Among the technologies the gas used in gasflooding test include steam, CO2and N2.Among the technologies the natural gas injection is a commonly methods for oil recovery.Because the hydrocarbon gas such as natural gas has some characteristics of the crude oil, itwould not damage the reservoirs during injection and could be mixed in a relatively lowpressures. However with the natural gas prices rise the natural gas injection would berestricted by economical factors in some extent, so accelerate research on the injection ofother gases, especially carbon dioxide and nitrogen.On the basis of original steam injection, carbon dioxide and nitrogen injection flooding isan effective approach to improve the exploiting efficiency and oil recovery. Carbon dioxide isa kind of gas with high solubility in both water and oil. It can make the oil volume expansionand the viscosity depressed when it solved into crude oil. Meanwhile, carbon dioxide has theexcellent functions of improving mobility ratio, raising the permeability of oil reservoirs andso on.Making effectively use of carbon dioxide in flu-gas can protect economic gas sources.The burners used in the oilfield include collapsible boat, gas fired boiler and oil burning boiler,these flue-gas usually contain9%~15%carbon dioxide,0%~85%nitrogen and a light oxygen,sulfur dioxide and water.Reclaim of carbon dioxide from flue gas of coal, gas or oil boilers can protect theenvironment and realize environment-friendly production. Carbon dioxide is the maincomponent what trigger the greenhouse effect, so restrict the content of carbon dioxide in theatmosphere is the key to stop greenhouse effect as the negative effects of carbon dioxide cannot be neglected. Therefore, reclaim carbon dioxide has great meaning in the point of solvingthe greenhouse effect. It is of great significance to reclaim carbon dioxide from flue-gas ofcombustor so as to apply it in gas injection producing, which may not only increase the oiloutput but also reduce environmental pollution.As the compression coefficient and volume factor of Nitrogen are lower than other gases,low solubility in water, similar viscosity with methane and it always presents foam state whenmixed with most fluids. which may has lifting function on the fluids. So it can be used inmany oil flooding methods such as miscible phase flooding to improve the recovery efficiency.The main of some heavy oil blocks recovery is still thermal recovery, such as burningnatural gas, each boiler discharges approximately480million Nm3flue gas per year. Thusprovide closer air resources for oil recovery, which is able to reduce production cost andprovide good resources for flue gas recovery.Gas injection is an important technology to enhance oil recovery. With different gas andreservoir, the gas and oil can form a immiscible or miscible state, and enhance oil recovery byreduce the interfacial tension, viscosity of oil and so on.During thermal recovery, the main components of injected gas are carbon dioxide andnitrogen. The research shows: using steam boiler and related flue-gas recycling equipment canrealize the gas injection, such as steam, carbon dioxide, nitrogen and their mixture well, it isalso good for increasing production and protect the environment.