Study of the Effect of Clay Particles on Low Salinity Water Injection in Sandstone Reservoirs

Abstract

Abstract:The need for optimal recovery of crude oil from sandstone and carbonate reservoirs around the world has never been greater for the petroleum industry. Water-flooding has been applied to the supplement primary depletion process or as a separate secondary recovery method. Low salinity water injection is a relatively new method that involves injecting low salinity brines at high pressure similar to conventional water-flooding techniques, in order to recover crude oil. The effectiveness of low salinity water injection in sandstone reservoirs depends on a number of parameters such as reservoir temperature, pressure, type of clay particle and salinity of injected brine. Clay particles present on reservoir rock surfaces adsorb polar components of oil and modify wettability of sandstone rocks to the oil-wet state, which is accountable for the reduced recovery rates by conventional water-flooding. The extent of wettability alteration caused by three low salinity brines on oil-wet sandstone samples containing varying clay content (15% or 30%) and type of clay (kaolinite/montmorillonite) were analyzed in the laboratory experiment. Contact angles of mica powder and clay mixture (kaolinite/montmorillonite) modified with crude oil were measured before and after injection with three low salinity sodium chloride brines. The effect of temperature was also analyzed for each sample. The results of the experiment indicate that samples with kaolinite clay tend to produce higher contact angles than samples with montmorillonite clay when modified with crude oil. The highest degree or extent of wettability alteration from oil-wet to intermediate-wet

Low-Salinity-Assisted Cationic Polyacrylamide Water Shutoff in Low-Permeability Sandstone Gas Reservoirs

“…Furthermore, we note that the low-salinity water-flooding technique has generated significant interest in improving hydrocarbon recovery. − Several mechanisms are responsible for enhanced oil recovery (EOR), because of low-salinity brine, which include, but are not limited to, double layer effect, wettability alteration toward more water-wet, and increased pH and reduced IFT. , Note that while this work focuses on polymer-augmented low-salinity EOR, it may be considered as an extension to the applications of low-salinity EOR.…”

Effect of Silica Nanoparticles on Fluid/Rock Interactions during Low Salinity Water Flooding of Chalk Reservoirs

“…Low salinity water flooding has emerged as an effective technique for improving oil recovery from some reservoirs [35][36][37][38][39][40][41][42]. However, increased calcite dissolution induced by low salinity interaction with chalk during flooding may lead to loss of rock integrity [43].…”

Geochemical Modeling and Microfluidic Experiments To Analyze Impact of Clay Type and Cations on Low-Salinity Water Flooding

“…The impact of clay type on wettability alteration and the resulting oil recovery under LSW injection has been previously reported, and it has been mostly a reflection of the reduction in the contact angle. − Collins et al suggest that LSW works best at high temperatures (∼100 °C), near pH 5, and when the clays are kaolinite (9–30% by volume). Clay minerals especially but not exclusively kaolinite were identified as a necessary component by a number of researchers. − Sina and Andrés Delgado investigated the individual performances of illite and kaolinite (type and content of clay) on the alteration of carbonate rock surface-wettability.…”