Co₂-eor And Geological Storage Study Of Jiangsu Caoshe Oil-field

With global warming, people are increasingly interested in reducing CO₂ emission. Geology sequestration is a promising storage method, and CO₂ storage during CO₂-EOR process is the most attractive method. Based on Caoshe oil field, this thesis analyzes the mechanism of CO₂-EOR and storage, evaluates CO₂ storage capacity, designes the process flow of the CO₂-EOR and storage demonstration project and assesses the feasibility of the demonstration project.This thesis investigates the physical and chemical properties of CO₂ in order to understand the mechanism of CO₂-EOR and storage, CO₂ can change the properties of oil by means of dissolving in it to enhance oil recovery, and CO₂ storage is achieved by means of occupying the pore volume of produced oil, dissolving in formation water and oil, and reacting with rock. On the basis of detailed geological investigation, numerical simulation method is used to predict the effect of development and CO₂ storage capacity, and it also provides available parameters for economic evaluation. Besides, Ecofys & TNO model, dissolving and volume model are used to evaluate the CO₂ storage capacity; through the analysis, dissolving and volume model and its evaluation results are recommended, oil recovery ratio can increase 18.9%, oil production can increase 26.84×104t, and CO₂ storage capacity is 69.01×104t. Based on the study of CO₂ capture technology, transportation technology and storage technology, this thesis finds the available CO₂ source for the demonstration project, design three transportation methods: low temperature liquid state transportation, high pressure dense phase state transportation and high pressure supercritical state transportation. Through the analysis, the process flow of high pressure supercritical state transportation is most simple and is cost-optimal. Furthermore, according to the component of produced gas, this thesis designs three processing schemes: gas turbine plant, purification of CO₂ and CO₂ cycling. Finally, a economic evaluation model is established to evaluate the economical efficiency of the demonstration project, the CO₂ storage cost is 25.78＄/tCO₂. Therefore, it is feasible to carry out the CO₂-EOR and storage demonstration project in Caoshe oil field.