3-D Model Studies of Alkaline Flooding Using Horizontal Wells

摘要

In this study, the effect of sodium hydroxide (NaOH) solution for the improved oil recovery of Garzan (26°API) crude oil was investigated using two different laboratory models. The effect of injection rate on oil recovery was investigated using a one-dimensional unconsolidated limestone reservoir model. The effect of horizontal and vertical well configurations on oil recovery was also studied using a 3-D physical model and various well configurations. As previously studied, the interfacial tension measurement of Garzan crude oil and NaOH solution interface was measured to find the optimum concentration of the alkaline solution that gave the minimum interfacial tension at the crude oil/alkaline solution interface at different salinity of the alkaline solutions. The results of the 1-D model tests showed that the NaOH solutions with increasing salinity has given the most significant incremental oil recovery, about 3 to 9% for Garzan crude oil. The results of the displacement tests showed that the injection flow rate of alkaline solution has an important effect on Garzan crude oil in spite of oil recovery achieved. The optimum injection flow rate for Garzan crude oil has been found as 183 cc/hr. A total of 6 runs were conducted to investigate the effect of horizontal-vertical well configuration on oil recovery by alkaline flooding. Alkaline flooding experiments were performed in three different well configurations: (1) a vertical injector and horizontal producer, (2) horizontal injector and horizontal producer, and (3) a vertical injector and vertical producer. The highest oil recovery was obtained through vertical injector-horizontal producer configuration.