Macro- and Microanalysis on Noncondensable Gas Antiwater Invasion in a Bottom Water Reservoir with a Rupturable...

Developing a bottom-water reservoir with rupturable interlayers is a significant challenge. This paper used a 2D visualization model to study the seepage characteristics of gas-water in two phases during noncondensable gas antiwater invasion. On this basis, the mechanisms of antiwater invasion and enhanced oil recovery (EOR) were summarized. The results show that bottom water advances from the crack of the interlayer to the oil layer, leading to a profile of radial flow. The major swept area occupies the scope near the horizontal well and the oil layer's middle part. Therefore, a lot of remaining oil distributes beside the crack of the interlayer. Noncondensable gas preferentially flows into the water-swept area due to a lower seepage resistance. Under gravity differentiation, the dispersed gas displaces the invaded bottom water downward, inhibiting water from invading and increasing the oil production rate. These studies provide practical guidance for analyzing bottom-water invading processes and designing suitable measures to develop such reservoirs.