A Laboratory Evaluation Of CO₂Injection For Zhuzhuang Oil Field

CO2flooding is a good enhance oil recovery (EOR) method to solve the problem that itis very difficult to enhance the recovery of low permeability reservoir even with the methodof water flooding. CO2flooding can not only effectively enhance the recovery of the laterstage of oil-field development but also can economically solve the problems like unbalance ofinjection and production appeared in the process of low permeability reservoir development.What’s more, CO2flooding makes a good use of carbon dioxide gas which is significant forreducing the greenhouse effect and environment protection.The mechanisms of CO2flooding are investigated in this paper. And based on thesemechanisms a serious lab experiments including PVT test, CO2huff-puff experiment, CO2flooding experiments and slim tube experiment were carried out.Some basic PVT parameters such as bubble point pressure, viscosity, density and so onof the crude oil from ZhuZhuang oil field were determined in PVT test experiments, and alsothe properties of crude oil with different CO2solubility were obtained from the test. The slimtube test is the most common way to determine the minimum miscibility pressure (MMP).And the slim tube experiment conducted in this paper shows that the MMP between CO2andthe crude oil from ZhuZhaung oil field is about22MPa. The results of CO2huff-puffexperiments reveal that parameters like soak time, choke pressure, injection volume andnumber of cycles can affect the oil recovery greatly. There different methods were selected inthe CO2displacement experiment. Experiment data indicate that the most efficient way ofCO2flooding is completely gas flooding followed by water alternate gas flooding and gasflooding after water flooding. And water flooding can not achieve a quite good recovery rateA conclusion can be drawn from all of the experiments that CO2flooding can enhance therecovery effectively and it is suitable for the target reservoir.