The Impact of Spatially Correlated Heterogeneity and Adsorption on Modified Salinity Water in Carbonates

Abstract

Modified salinity water (MSW) core flooding tests conducted in carbonates often exhibit a delay in the additional oil recovery. It has been suggested that the ionic adsorption process controls this delay. In this study, we examine the adverse effect of the adsorption process on the performance of MSW flooding in various models categorized as layered and heterogeneous reservoirs and a North Sea field sector model. To evaluate the impact of porous media's heterogeneity on the delay caused by the adsorption, we introduce the net present volumetric value based on which the cost of delay is calculated. This evaluation is achieved by comparing the calculated cost of delay for heterogeneous systems and that of their equivalent homogeneous porous media. It is found that, as the level of reservoir heterogeneity increases, the adverse effect of ionic adsorption on the improved oil production decreases. Further, computational results suggest that the connectivity index, which is defined as the effective permeability between injection and production wells divided by the average permeability, is a better alternative to the vorticity index to describe the impact of the delay of additional oil recovery in heterogeneous reservoirs subjected to MSW flooding.

Impact of Wettability Alteration on the Front Instability of Immiscible Displacement in Porous Media

“…The relative permeability curves history‐matched by Taheriotaghsara, Bonto, et al. (2020) and Taheriotaghsara, Hosseinzadehsadati, and Nick (2020) are used here. Various history matched core flooding observations (Ayirala et al., 2020; Dang et al., 2016; Nasralla et al., 2018; Sorop et al., 2015; Wang & Alvarado, 2016) obtain a similar behavior for relative permeability curves and conclude that changing the wettability from non‐water‐wet to water‐wet condition shifts relative permeability curves of MSW to the right.…”

“… (a) Relative permeability for formation water (FW), seawater (SW), and modified salinity water (MSW) obtained from experimental data for carbonate rocks (Taheriotaghsara, Bonto, et al., 2020 and Taheriotaghsara, Hosseinzadehsadati, & Nick, 2020). (b) Capillary pressure for FW or SW and MSW water (we assume that the FW and SW display the same capillary pressure).…”

“…Because the wettability alteration changes the shape of relative permeability curves (Mohammed & Babadagli, 2015), here, we select three sets of relative permeability curves to illustrate the impact of wettability alteration on shock front stability for both secondary and tertiary MSW flooding schemes. The relative permeability curves history-matched by Taheriotaghsara, Bonto, et al (2020) and Taheriotaghsara, Hosseinzadehsadati, and Nick (2020) are used here. Various history matched core flooding observations (Ayirala et al, 2020;Dang et al, 2016;Nasralla et al, 2018;Sorop et al, 2015;Wang & Alvarado, 2016) obtain a similar behavior for relative permeability curves and conclude that changing the wettability from non-water-wet to water-wet condition shifts relative permeability curves of MSW to the right.…”

Role of Relative Permeability Hysteresis in Modified Salinity Water Flooding

“…This procedure captures both the effect of wettability alteration and the hysteresis.The conceptual model used in this study (Fig. 7) bears a close resemblance to the one proposed by Taheriotaghsara [29]. For the sake of simplicity, the same relative permeability is assigned for formation water (FW) and seawater as high salinity water.…”

A review on low salinity waterflooding in carbonates: challenges and future perspective

“…Their study did not encompass the effect of fractures and diffusion rates on the final oil recovery. (Taheriotaghsara et al 2020) studied the delay in oil production due adsorptive ion transport and the diffusioncontrolled wettability alteration for heterogeneous carbonate reservoirs, when employing low salinity waterflooding in such reservoirs. They tested various types of heterogeneities such as homogeneous reservoirs, layered system, and sector scale model with contrasting physical properties.…”