One dimensional slim tube displacement study of one the Iranian oil reservoirs during separator gas injection

Gas injection is one of the enhanced oil recovery methods that depends on the miscibility conditions. Based on minimum miscibility pressure (MMP), gas injection or gas flooding might be miscible or immiscible. For determining MMP, displacement tests are conduct at different operating pressures. By increasing displacement pressure, the oil recovery is increased to reach MMP and then remain constant. In this study, the MMP of separator gas and an Iranian oil reservoir is estimated using one dimensional slim tube test. One dimensional slim tube test is classified as multiple contact or dynamic miscibility test. Gas is injected in constant rate and the displacement pressure is recorded continuously. The produced oil is flashed to atmospheric condition and compositional analysis is done using gas chromatography. The volume of produced oil is measured and the amount of oil recovery is plotted versus the pore volume of injected gas. The test is done at 6 different pressures. The results show that the oil is recovered more than 09 for gas injection at miscible conditions. For determining miscibility condition, the oil recovery is plotted versus pressure. Miscibility condition is confirmed by visual observations of phase behavior and the effluent gas compositional analysis. Oil recovery at 1.1PV of injected gas was compared for 6 different pressures. As the pressure is increased, the higher amount of oil recovery is reached.

Keywords:

Enhance oil recovery , Gas injection , Minium mscibili ty , pressave (MMp) 1-Dslin Tube test