Modeling the influence of body forces on cyclic flooding of an oil reservoir

Abstract

Over the past decade, oil production in Western Siberia has declined by 10%, while the water cut–the proportion of water in the total fluid produced – has increased.

At the same time, the average oil recovery factor remains relatively low at 38%. This situation emphasises the urgency of finding and studying cheap and effective methods to enhance oil recovery. This study analyses a two-dimensional filtration, two-phase flow model of a dual-layer reservoir, considering two scenarios: (A) the low-permeability layer located above the high-permeability layer, and (B) the low-permeability layer situated below the high-permeability layer. The main aim of this paper is study how body forces influence the oil saturation structure in a dual-layer reservoir during cyclic waterflooding. A second aim is to determine how the gain in oil production depends on the phase density difference (Δρ) using cyclic waterflooding method. Using numerical simulation, the authors performed a series of calculations by varying the density difference between oil and water for both reservoir configurations. The results show that Δρ has a significant impact on structure of oil saturation and on the duration of deposit development. As Δρ increases, the effectiveness of cyclic waterflooding decreases.