Study On Experiment And Simulation Of CO₂ Injection In Palogue Oilfield Of Republic Of The Sudan

Palogue Oilfield, Block 3/7 of Republic of the Sudan is the biggest oilfield found beyond the sea in this thirty years with the totle reserves of twenty nine billion barrels. Aim at the reserves of CO₂, the authors research on the method of CO₂ drive and CO₂ huff-n-puff, using laboratory test and simulation. The main research results we get are as following:First, In the CO₂ drive and microscopic model experiment, it is clear that the driving procedure is immiscible drive.Second, In the CO₂ drive experiment, we studied the method of CO₂ continuous drive, CO₂ slug and WAG on the slim tube model. We found that the method of CO₂ continuous drive can get a considerable effect, the method of CO₂ slug and WAG is better than CO₂ continuous drive, WAG is the best method of all considering all.Third, In the microscopic model test, the driving procedure and the distribution of residual oil are observed. It is concluded that the driving procedure is immiscible drive on the pressure of the formation; with the increase of pressure, the effect of dissolving, reduction in viscosity and the fluid of oil become strong, so we can got more oil.Fourth, Though the CO₂ huff -puff experiment indoor, we researched on the effect of CO₂ huff and puff. The experiment aimed at the injection volume of CO₂, soaked period,bottom hole pressure and so on. The experimental results show that the soaked period has restricted effect while bottom hole pressure has important effect, optimal injection volume exist, putting down the pressure once and anterior three cycle get good effect.Fifth, we studied mechanism and feasibility of using CO₂ as a displacement medium, the influence factors in the method of CO₂ huff and puff by simulation. And we got some parameter as a good reference to the oilfield.The above studies show that CO₂ is a displacement medium for improving oil recovery with great potentialities. It is valuable for further research and oil field test.