Experimental and material balance equations analyses of cyclic solvent injection based on a large 3D physical model

Comparison between two tests indicates that the gravity force still dominates the recovery factor rather than the model size. The model shape significantly affects the change of production rate, but not the average production which is mainly determined by the original oil in place (OOIP). The same behavior of minimum production pressure occurred in two tests with the same pressure decline rate. Ndi of each cycle in the large 3D test is successfully obtained through the established MBE. Then Ndi are used to obtain Esd and Rd. The results show that Esd first increases from 4.75% to 10.70% with the growth of solvent chamber. Then it keeps around 13.78% for main stage. During the very late stage, Esd decreases to 10.11%. Not as Esd dramatically varies, Rd in each cycle is in the range of 28%-34%, which indicates that recovery of CSI has much more potential. A higher recover factor could be expected if Esd and Rd would be both improved. By the tuned Rs and Bo in the large 3D case, Ndi of each cycle in the cylindrical model CSI test is matched with very good agreement (average R2 = 0.9899), which suggests that the established MBE is reliable to evaluate production performance of CSI.