Enhanced Polyacrylamide Polymer Gels Using Zirconium Hydroxide Nanoparticles for Water Shutoff at High Temperatures: Thermal and Rheological Investigations

A Review of Recent Developments in Nanomaterial Agents for Water Shutoff in Hydrocarbon Wells

Reducing water production from hydrocarbon wells is one of the major requirements to prolong the life span of production wells. Gel treatment is commonly regarded as one of the traditional cost-effective methods for water shut-off applications. Different gel systems have been developed to overcome the challenges of performing a successful water shut-off treatment. Each gel system has its advantages and disadvantages. A new proposed technology is to enhance the gel performance by utilizing nanomaterials in its composition. Nanomaterials such as nanosilica, nanoclay, and graphene can significantly modify gel properties to improve plugging efficiency. This paper provides a brief review of the added value of using nanomaterials in the structure of polymer in situ gel, preformed particle-gel, and nanosilica-based fluid. Nanomaterials such as nanoclay, nanosilica, and nanographene are capable of adjusting the properties of in situ gel, such as control of gelation time (9-10) hours and enhancing gel strength up to 4.5 times. Nanomaterials also improved the swelling ratio of the preformed particle-gel by up to 400%, accompanied by increased gel strength. Notably, nanosilica-based gels exhibit an exceptional plugging efficiency (100%). Additionally, the paper discusses how modeling can be used to overcome operational challenges in terms of placement and plugging performance.

Investigation of Polymer Gel Reinforced by Oxygen Scavengers and Nano-SiO2 for Flue Gas Flooding Reservoir

Polymer gel plugging is an effective technique for gas mobility control in flue gas flooding reservoirs. However, the performance of polymer gels is extremely susceptible to the injected flue gas. A reinforced chromium acetate/partially hydrolyzed polyacrylamide (HPAM) gel, using thiourea as the oxygen scavenger and nano-SiO₂ as the stabilizer, was formulated. The related properties were evaluated systematically, including gelation time, gel strength, and long-term stability. The results indicated that the degradation of polymers was effectively suppressed by oxygen scavengers and nano-SiO₂. The gel strength would be increased by 40% and the gel kept desirable stability after aging for 180 days at elevated flue gas pressures. Dynamic light scattering (DLS) analysis and Cryo-scanning electron microscopy (Cryo-SEM) revealed that nano-SiO₂ was adsorbed on polymer chains by hydrogen bonding, which improved the homogeneity of gel structure and thus enhanced the gel strength. Besides, the compression resistance of gels was studied by creep and creep recovery tests. The failure stress of gel with the addition of thiourea and nanoparticles could reach up to 35 Pa. The gel retained a robust structure despite extensive deformation. Moreover, the flow experiment indicated that the plugging rate of reinforced gel still maintained up to 93% after flue gas flooding. It is concluded that the reinforced gel is applicable for flue gas flooding reservoirs.

Reactive Additive Capillary Stamping with Double Network Hydrogel-Derived Aerogel Stamps under Solvothermal Conditions

Integration of solvothermal reaction products into complex thin-layer architectures is frequently achieved by combinations of layer transfer and subtractive lithography, whereas direct additive substrate patterning with solvothermal reaction products has remained challenging. We report reactive additive capillary stamping under solvothermal conditions as a parallel contact-lithographic access to patterns of solvothermal reaction products in thin-layer configurations. To this end, corresponding precursor inks are infiltrated into mechanically robust mesoporous aerogel stamps derived from double-network hydrogels. The stamp is then brought into contact with a substrate to be patterned under solvothermal reaction conditions inside an autoclave. The precursor ink forms liquid bridges between the topographic surface pattern of the stamp and the substrate. Evaporation-driven enrichment of the precursors in these liquid bridges, along with their liquid-bridge-guided conversion into the solvothermal reaction products, yields large-area submicron patterns of the solvothermal reaction products replicating the stamp topography. For example, we prepared thin hybrid films, which contained ordered monolayers of superparamagnetic submicron nickel ferrite dots prepared by solvothermal capillary stamping surrounded by nickel electrodeposited in a second orthogonal substrate functionalization step. The submicron nickel ferrite dots acted as a magnetic hardener, halving the remanence of the ferromagnetic nickel layer. In this way, thin-layer electromechanical systems, transformers, and positioning systems may be customized.

Nanotechnology Applied to Thermal Enhanced Oil Recovery Processes: A Review

The increasing demand for fossil fuels and the depleting of light crude oil in the next years generates the need to exploit heavy and unconventional crude oils. To face this challenge, the oil and gas industry has chosen the implementation of new technologies capable of improving the efficiency in the enhanced recovery oil (EOR) processes. In this context, the incorporation of nanotechnology through the development of nanoparticles and nanofluids to increase the productivity of heavy and extra-heavy crude oils has taken significant importance, mainly through thermal enhanced oil recovery (TEOR) processes. The main objective of this paper is to provide an overview of nanotechnology applied to oil recovery technologies with a focus on thermal methods, elaborating on the upgrading of the heavy and extra-heavy crude oils using nanomaterials from laboratory studies to field trial proposals. In detail, the introduction section contains general information about EOR processes, their weaknesses, and strengths, as well as an overview that promotes the application of nanotechnology. Besides, this review addresses the physicochemical properties of heavy and extra-heavy crude oils in Section 2. The interaction of nanoparticles with heavy fractions such as asphaltenes and resins, as well as the variables that can influence the adsorptive phenomenon are presented in detail in Section 3. This section also includes the effects of nanoparticles on the other relevant mechanisms in TEOR methods, such as viscosity changes, wettability alteration, and interfacial tension reduction. The catalytic effect influenced by the nanoparticles in the different thermal recovery processes is described in Sections 4, 5, 6, and 7. Finally, Sections 8 and 9 involve the description of an implementation plan of nanotechnology for the steam injection process, environmental impacts, and recent trends. Additionally, the review proposes critical stages in order to obtain a successful application of nanoparticles in thermal oil recovery processes.