A Comprehensive EOR Study Using Low Salinity Water in Sandstone Reservoirs

Alotaibi, Mohammed B.; Azmy, Ramez; Nasr‐El‐Din, Hisham A.

doi:10.2118/129976-ms

Cited by 51 publications

(15 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Therefore, chemical reactions with carbonate particles are also expected to be dramatically different. In sandstone reservoirs, clays control the interaction, especially with the low salinity level of water (Zhang and Morrow 2006;Alotaibi et al 2010). But, in carbonate reservoirs, the effect of salinity is more pronounced.…”

Section: Resultsmentioning

confidence: 99%

Electrokinetics of Limestone and Dolomite Rock Particles

Alotaibi

Nasr‐El‐Din

Fletcher

2011

SPE Reservoir Evaluation &Amp; Engineering

123

View full text Add to dashboard Cite

High-salinity water such as seawater, or formation brines, is frequently injected in carbonate reservoirs. Ion interactions between injection water, reservoir fluids, and rock surface are quite complex. It has recently come to be believed that the chemistry of injection water can significantly enhance oil recovery. Several reaction mechanisms were suggested, including rock dissolution, change of surface charge, and/or sulfate precipitation.This study attempts to characterize the electrokinetics of limestone and dolomite suspensions at 25 and 50°C. In addition, reaction mechanisms at the water/rock interface were established. Synthetic formation brine, seawater, and aquifer water were chosen from Middle East reservoirs. Carbonate particles were soaked in high-and low-salinity water. A phase-analysis-light-scattering (PALS) technique was used to determine the zeta potential (surface charge) of carbonate particles over a wide range of pH, ionic strength, and temperature.Zeta potential of limestone particles was significantly affected by calcium ion. Low-salinity water created more negative charges on limestone and dolomite particles by expanding the thickness of the diffuse double layer. Individual divalent cations decreased the zeta potential of limestone particles in sodium chloride solutions, while sulfate ions showed a negligible effect. Limestone particles in high-salinity water had decreased zeta potential. The solubility of calcium ions increased as temperature was increased and thus created additional negative charges. The absence of sulfate in aquifer water strongly influenced the dolomite surface charge. In summary, surface-charge adjustment from positive to negative can alter the wettability of carbonate rock from preferentially oil-wet to waterwet. As a result, residual-oil saturation should be decreased. IntroductionInterfacial phenomena at carbonate/water interfaces are controlled by the electrical-double-layer 1 (EDL) forces. Therefore, it is necessary to understand the behavior of the ions' interactions with the rock surface. Charged species 2 are transferred across any solid/liquid interface only until reaching equilibrium. The interface can be visualized as a semimembrane 3 that allows the common charged species between solid and solution to pass through. These species are called potential-determining ions. As a result of the relative motion between the charged dispersed phase and the bulk liquid, the EDL is sheared. The potential, at this shear plane, is commonly called electrokinetic or zeta potential (). Various methods are applied to measure the potential at the shear plane. However, the most commonly used technique is the electrophoresis method (Pierre et al. 1990).

show abstract

Section: Resultsmentioning

confidence: 99%

Electrokinetics of Limestone and Dolomite Rock Particles

Alotaibi

Nasr‐El‐Din

Fletcher

2011

SPE Reservoir Evaluation &Amp; Engineering

123

View full text Add to dashboard Cite

show abstract

“…These have demonstrated its successful application in other laboratory experiments and field trials (e.g. Loaharjo et al, 2007;Lager et al, 2008a;2008b;Patil et al, 2008;Alotaibi et al, 2010;Cissokho et al, 2010; see, for example, Figure 1a Seccombe et al, 2010). Moreover, there has been increasing focus on the collection of laboratory data to explain the LSE, including contact angles (e.g.…”

Section: Introductionmentioning

confidence: 86%

Evidence, mechanisms and improved understanding of controlled salinity waterflooding part 1: Sandstones

Jackson

Vinogradov

Hamon

et al. 2016

Fuel

167

View full text Add to dashboard Cite

It is widely accepted that oil recovery during waterflooding can be improved by modifying the composition of the injected brine, typically by lowering the total salinity to less than 5,000ppm. Numerous laboratory experiments and field tests, in both clastic and carbonate rock samples and reservoirs, have demonstrated this 'low salinity effect' (LSE). However, despite a plethora of studies and data, the LSE remains poorly understood. Evidence to support the widely held view that improved recovery is conditional on the presence of clay minerals in sandstones, multivalent ions in the formation brine, and significant dilution of the injection brine, is surprisingly scarce. Moreover, there is no method to determine the optimum injection brine composition for a given crude-oil-brine-rock (COBR) system. Many studies have reported the successful application of controlled salinity water injection. However, many others (and more unpublished) observed no benefit, and the available data are often inconsistent and contradictory. This review collects and summarizes the available data for the first time and discusses the poreto mineral-surface-scale mechanisms that have been proposed to explain the LSE. Based on this, it outlines an integrated experimental programme that could be used to identify the optimal injection brine composition for a given COBR system. The available evidence suggests that the LSE is real, and is caused by one or more pore-to mineral-surface-scale mechanism(s) which facilitate improved oil recovery at the core-to reservoir-scale. These mechanisms occur at COBR interfaces, and are multi-ion exchange (MIE), local increase in pH (∆pH) and double layer expansion (DLE). However, the available evidence is not sufficient to unambiguously identify which, if any, of these mechanisms are essential. Other proposed mechanisms, such as clay swelling and fines migration, formation of natural surfactants at elevated pH, reduction in oil/brine interfacial tension, and increased solubility of polar oil compounds in brine, may occur in some cases but do not appear to be necessary to observe improved oil recovery. Understanding is hampered by a lack of common experimental conditions across length-scales. Core-scale measurements are often obtained at reservoir conditions of pressure, temperature, brine salinity and crude oil composition. In contrast, pore-and mineral-surface-scale measurements such as atomic force or scanning electron microscopy, contact angle and wetting surface, adsorption and adhesion, are often obtained at laboratory temperature and pressure, lower brine salinity and simplified crude composition. These contrasting experimental conditions may explain the contradictory data obtained to date. A common feature of all three proposed mechanisms for the LSE is that they lead to changes in zeta potential at mineral surfaces, either through changes in mineral surface charge (MIE, ∆pH) or changes in the thickness of the double layer (DLE). Thus they change the magnitude of the electrostatic forces acting between ...

show abstract

“…Thermal energy in combination with LSW water flooding, in the form of hot LSW water flooding, can be applied to simultaneously decrease the viscosity of the heavy oil and alter the wettability of the porous media to attain higher oil recovery. Alotaibi et al and Tang et al reported lower contact angle and higher oil recovery, respectively, after increasing the displacement temperature in LSW injection [62,63]. Contrary to this observation, Soraya et al [64] found lower oil recovery at higher temperatures by tertiary LSW.…”

Section: Lsw/hot Water Hybrid Eor Techniquementioning

confidence: 94%

Hybrid EOR Methods Utilizing Low-Salinity Water

Pourafshary¹,

Moradpour²

2019

Enhanced Oil Recovery Processes - New Technologies

View full text Add to dashboard Cite

Low-salinity water (LSW) flooding has been applied in sandstone and carbonate formations to improve oil recovery. Wettability alteration by LSW has been identified as the dominant driving mechanism for the incremental oil recoveries. LSW flooding has been combined with other EOR methods to develop new hybrid approaches to improve crude/brine/rock (CBR) interactions with the objective of overcoming some of the LSW flooding downsides, which include oil trapping and fine migration. Hybrid methods can provide higher oil recovery than each stand-alone technique. For instance, changes in gas solubility during LSW injection positively affect the performance of LSW/gas hybrid injection. LSW/surfactant flooding can contribute to incremental recovery by simultaneously lowering interfacial tension (IFT) and wettability alteration. The synergistic effect of fluid redistribution by LSW and enhanced water mobility by polymer flooding improves oil detachment and displacement in porous media through the application of the hybrid approach LSW/polymer flooding. Nanoparticles (NPs), mainly SiO 2 , can alter wettability toward more water wetness in combination with LSW, and hot LSW can improve heavy oil production by reducing viscosity. Hence, the synergistic effect of hybrid EOR methods based on LSW flooding is considered a novel EOR approach to improve oil recovery.

show abstract

A Comprehensive EOR Study Using Low Salinity Water in Sandstone Reservoirs

Cited by 51 publications

References 33 publications

Electrokinetics of Limestone and Dolomite Rock Particles

Electrokinetics of Limestone and Dolomite Rock Particles

Evidence, mechanisms and improved understanding of controlled salinity waterflooding part 1: Sandstones

Hybrid EOR Methods Utilizing Low-Salinity Water

Contact Info

Product

Resources

About