Method for recovering carbon dioxide

Abstract

The invention relates to a petroleum extraction technology, in particular to a method for recovering carbon dioxide in produced gas by driving in a petroleum extraction process. The method comprises the following steps of: (1) compressing, cooling and separating: cooling and separating a part of moisture and heavy hydrocarbons out through gas compression; (2) distilling de-oiled water to obtain CO2 gas of which the water content is less than or equal to 200ppm; (3) liquefying and stripping to obtain a finished CO2 liquid which meets an oil driving requirement; (4) and stripping at a low temperature for further recovering CO2 and concentrating methane, ethane and other organic matters. In the method, oilfield CO2 produced gas by driving is recovered by adopting rectifying and low-temperature stripping coupling methods, the flow is simple, and convenience is brought to operation; and as proved by practice, the CO2 yield is over 98 percent, the energy consumption is low, light oil and oilfield fuel gas are by-produced, byproducts have high economic values, and the method has a good application effect.

Description

technical field [0001] The invention relates to oil extraction technology, in particular to a method for recovering carbon dioxide in the flooding gas produced in the oil extraction process. Background technique [0002] With the continuous deepening of the development degree, my country's oil fields have entered the middle and late stages of development. At this stage, in order to further enhance the recovery rate, major oil fields are studying the use of carbon dioxide flooding technology. At present, carbon dioxide flooding technology has been applied in Daqing Oilfield, Jiangsu Oilfield, East China Petroleum Bureau, Northeast Petroleum Bureau, Xinjiang Oilfield and other petroleum units. However, when the amount of carbon dioxide gas injected reaches a certain level, the oil well will produce carbon dioxide through gas. At present, there is a lack of corresponding recovery technology in China, resulting in waste of gas sources. At present, the recovery methods of carbo...

AI Technical Summary

Problems solved by technology

The amine absorption method needs to be connected with a dehydration device in series, the operation is relatively complicated, the solvent is corroded, degraded, easily polluted, the circulation volume is large, and the energy consumption is relatively high, so it is not suitable for oil field recovery; the low-temperature separation method has high investment costs, careless operation, and CO 2 Easy to cure, high energy consumption