Prediction of water breakthrough during waterflooding under unstable water displacement front conditions

Abstract

Unsteady modifications of waterflooding technologies are usually used as the main technique of reservoir pressure maintenance and enhanced oil recovery in the development of hydrocarbon fields. The disadvantages and imperfections of the conventional approach remain even after wide application of geological and hydrodynamic mathematical modeling and its truncated modifications, including proxy models, synthetic models and other simplified versions. At this stage it was not possible to achieve a fullfledged unification of waterflooding technology, because the theory of two-phase flow filtration created by Buckley-Leverett does not allow taking into account the influence of instability of the displacement front and its negative consequences, provoking a jump change and triple water saturation. This study attempts to return to the solution of this problem and proposes an alternative concept of monitoring and optimization of unsteady waterflooding of oil deposits, taking into account the consequences of instability of the front of oil displacement with water. Keywords: water flooding; water saturation; instability of the displacement front; optimization; catastrophe theory; phase plane.