The Evaluation And Research Of The Purification And Drive Technology Of The Produced Carbon Dioxide

This article described the characteristics of supercritical carbon dioxide,as well asits application in all respects,and focused on the application of flooding.Studied on the identification of the cause of formation of carbon dioxide from Songliao Basin,Combined with the temperament characteristics of this natural gasfield,ultimately determined the MDEA carbon removal process through analysis and comparison.At the same time,this paper also studied the nature of the carbon dioxide recovery,and analyzed the necessity of further purification.This article focused on the research and evaluation of carbon dioxide purification process,which included dewater.condensation and liquefaction process.Used the molecular sieve dehydration in the ehydration process,which used one tower to adsorb,and two towers to regenerate,through contrasting and tanalysising of the dewpoint and the water content,determined the optimal switching cycle of 8 hours.The article also did the material balance?analysised the operating parameters and accounted for the main equipment,which included the vaporliquid separator,purification,regeneration tower,and air compressors heaters,etc.The device of molecular sieve dehydration unit running smoothly,the operating parameters are within the scope of design,The volume fraction of carbon dioxide reached to 98.59%-98.89%and the dewpoint reached to-17.5?--3.4?,therefore the process needed to further purification,the condensation and liquefaction process used the cold of liquefied ammonia device to devolatilize the carbon dioxide after dehydrate with the refrigeration from vaporizable ammonia.The Liquefied carbon dioxide kept in reserve with a low-temperature and low-pressure storage tanks,the article also analysised the operating parameters and accounted for the main equipment,and the device of molecular sieve dehydration unit ran smoothly,the operating parameters were within the scope of design.The purified carbon dioxide content was 99.27%-99.82%,the dewpoint of the carbon dioxide after purification was-43.5?--14.1 ?,and the water content was 10.3 ppm-51.2 ppm,which all met the requirements of GB 17820-1999 and GB 50251-2003.Then brought the temperature of carbon dioxide to 31.06 ?,the pressure to 7.39MPa,it will reached thesupercritical state to be flooding.This article aslo focused on the different nature of the crude oil from produced fluid between carbon dioxide flooding and water flooding.We used the method of adsorption to analyze the content of resin and asphaltene,and we researched on the stability of emulsifiability which was effected by the resin and asphaltene with the method of watching the exhalation rate of the water.And then we had further description of the difference by the analytical data of the acid number,the viscosity and the interfacial tension.The results showed that the acid number and the content of resin and asphaltene of the crude oil from the carbon dioxide flooding produced fluid were all more than the water flooding one,and the viscosity and the interfacial tension of the crude oil from the c flooding produced fluid were the lower one.All the elements resulted in the emulsifiability of the crude oil from the carbon dioxide flooding produced fluid was more than the water flooding.