Smart waterflooding (SWF), an emerging EOR technique, was first investigated in sandstone reservoirs. However in recent years, the effect of smart water on carbonate reservoirs has gained wide interest. Despite the increasing number of research and publications in this area, the mechanism enhancing the recovery is still not fully understood. Wettability alteration and reduction in interfacial tension (IFT) have been identified as the two most dominant mechanisms. Divalent ions such as sulfate (SO42-) are found by many investigators to show promising results during SWF. However, limited research has been carried out to investigate the effect of trivalent ions. The objective of this study was to investigate the potential of phosphate (PO43-) spiked brines as a viable EOR technique in tight carbonate reservoirs. Seawater with different dilution factors and varying concentration of phosphate ions were investigated against non-phosphate brines. Impact of these brines on wettability alteration was qualitatively monitored by tracking the rate of contact angle change on several aged-carbonate core samples subjected to varying aging periods. Various designed phosphate brines were tested at elevated temperature of 90 °C, and IFT was also measured at both ambient and elevated temperature (90 °C) to complement our findings. To identify the impact of phosphate ions on wettability alteration due to brine/crude oil/rock interactions, carbonate core samples were prepared having initial contact angle ranging from 130° to 160°. The rate of contact angle change observed ranged from 9° to 36° as a function of varying composition of smart brines. A slight decrease in IFT was observed when lower salinity brines were used without phosphate. Phosphate spiked brines show a near surfactant reduction in IFT, compared to the low salinity brines. Smart brines with higher concentration of phosphate achieved better results than those with lower concentration.

With the imminent global water crisis, it is imperative to revolutionize how water as a commodity is managed. Currently, there is a disconnect between how various sectors of the society withdraw and consume water especially in hydrocarbon‐rich, water scarce regions such as the Middle East. This study proposes a multi‐criteria, multidisciplinary decision analysis model for integrated technology development across private and public sectors in such regions. The increasing water stress provides the oil and gas industry an opportunity to play a pivotal role in harnessing its technologies to sustainably support the water demand. The proposed concept is supported with case studies highlighting challenges and innovative solutions applied across the globe. This study builds a case for a framework on the basis of a step‐change opportunity to manage water needs and effectively plan technology, investment, and regulatory requirements for sustainable access to future sustainable freshwater management.

Use of nanoparticles as a method for enhancing oil recoveries has become an attractive prospect. Experimental evidence has shown that this technique possesses the ability to improve recoveries via wettability alteration and interfacial tension reduction amongst other strategies. In this study, we analyze the potential of nanoparticles employed in coreflood experiments. Low concentration acid was added to aid in the dispersion of the nanoparticles in the brine by protecting them from being aggregated, while enhancing the stimulation of the tight porous media. Electrokinetics was also implemented following a sequential as well as a simultaneous approach to further stimulate the fluids injected, controlling their mobility, and therefore, increasing the depth of penetration within the porous media. Several coreflood experiments were carried out on highly heterogeneous carbonate samples of Middle Eastern origin with permeabilities of around 0.1 mD. Zeta potential measurements were conducted on the inlet side of the preserved core-plugs after the conclusion of each coreflood. The findings indicated a close connection between the rate of wettability alteration observed over the duration of nano-acid fluid injection and mode of electrokinetic application. The best performing nano-acid fluids correlated with the highest shift in the magnitude of the zeta potential across all tested strategies. Results show that oil recovered via this hybrid technique was mostly 10–15% higher than that derived when only smart brine was employed.

Over the past few years, there has been significant interest in the potential of hybrid nanoparticle–acid fluid (HNAFs) for improved oil recovery. This comprehensive study investigates the effects of nanoparticles and acid on interfacial tension (IFT) to establish a relationship between brine properties and the oil/brine IFT. This investigation is one of the first regional studies conducted utilizing candidate field data from the Middle East. Based on the literature review and screening studies conducted, a seawater (SW)-based HNAF was formulated with nanoparticles (SiO2, Al2O3, and ZnO) and HCl to measure their effect on IFT. A total of 48 formulations of HNAFs, nanofluids with and without acid, were analyzed with crude oil from a candidate field. IFT measurements were subsequently conducted using the pendant drop method under ambient conditions and in a high-pressure, high-temperature reservoir environment. Results showcased that IFT reduction was observed by increasing the acid concentration with SiO2 and Al2O3, although a reverse trend was observed with ZnO. Moreover, it was observed that IFT varied with increasing concentrations of nanoparticles, and at certain acid concentrations, IFT reduced significantly with higher nanoparticle concentrations. From the Amott studies, a clear signature was achieved, with ZnO exhibiting a total of 31.4% oil recovery, followed by SiO2 (27.3%) and Al2O3 (23.7%). The results of this study may assist in defining a screening criterion for future displacement (oil recovery) studies involving the presented nanoparticles. The results also reveal further the mechanisms involved in IFT reduction by hybrid nano–acid fluids and their potential for significant applications in the Middle East.

Surfactant Foam assisted CO2 EOR, though getting traction for its environomic mobility control potential, faces numerous challenges for deployment in HPHTHS heterogeneous carbonate reservoirs. Amongst the major challenges, the first is the lack of a surfactant formulation compatible with our carbonate reservoirs and the second is the absence of a foam and CO2 front monitoring tool either at laboratory or field scale. In this study, a novel monitoring technique has been developed to track quality of the foam while core-flooding. This is essential to capture the onset formation, development rate and break-through of the said foam across varying length of core-plugs. This has been previously conducted in lab-scale by virtue of pressure response with or without expensive imaging methods. This tool complements the conventional method of studying pressure response with resistance measurements across the core allowing tracking of the foam generation and propagation. Various preconditioning smart brines (SB) were alternatively injected with the non-ionic surfactant APG, co-injected with gas, to generate foam in-situ in carbonate reservoir samples. In addition, we briefly discuss a new idea involving resistivity and pressure measurements for the optimization of foam (and CO2 foam) injection into porous media The foam generation, stability and breakthrough were studied as a function of salinity, ion composition and injected pore volumes of the various brines and surfactant. Core-plugs of 2 different rock types were flooded with 4 variations of smart brines at a constant flow rate. The tested formulations were ramped up from 2 to 8 pore volumes. The response of the ΔP/PV integrated with the Δρ/PV curves were analysed to detect foam generation and breakthrough. This allowed an immediate characterization of the foam performance providing capability of tracking the foam formation/dissipation across the length of the core-plugs, essential for compatible successful foam formulation. This novel method allowed for instantaneous resistance observations in lab-scale along with the pressure response. The performance of the monitoring technique provided a new dimension in understanding foam flooding. This was integrated to provide comprehensive analysis of the formulated foam. Our innovative method provides the capability of quicker screening to successfully generate foam in-situ in high salinity, hardness and heterogenic environment.