226 research outputs found

    Epoxy Phosphonate Ester as a Coupling Agent for Transition Metal and Metal Oxide Surfaces

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    A method for surface modification of a substrate comprising surface oxide and/or hydroxy groups, with a compound comprising an ester group and an epoxy ring, wherein the epoxy group remains intact after the reacting. A method for surface modification of a substrate comprising surface oxide and/or hydroxy groups, with a compound comprising an ester group and a functionalized epoxy ring, wherein the functionalized epoxy group remains intact after the reacting. A composite material comprising surface-modified metal oxide nanoparticles dispersed within a polymeric material, wherein the surface modification comprises a compound comprising an ester group and an epoxy ring is also described

    Re-Crosslinking Particle Gel for Coâ‚‚ Conformance Control and COâ‚‚ Leakage Blocking

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    The present invention generally relates to the composition of particle gels for CO2-EOR and CO2 storage. More particularly, CO2 resistant particle gels are provided that can re-crosslink at subterranean conditions. These particle gels can be deployed to improve the conformance of CO2 flooding, CO2 huff-puff, or Water-Alternative-Gas (WAG). The applications may also involve CO2 storage, such as the blocking of CO2 leakage and similar CO2 processing

    Comprehensive Review of Polymer and Polymer Gel Treatments for Natural Gas-Related Conformance Control

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    Conformance problems often exist in natural gas-related activities, resulting in excessive water production from natural gas production wells and/or excessive natural gas production from oil production wells. Several mechanical and chemical solutions were reported in the literature to mitigate the conformance problems. Among the chemical solutions, two classes of materials, namely polymer gels and water-soluble polymers, have been mostly reported. These systems have been mainly reviewed in several studies for their applications as water shutoff treatments for oil production wells. Natural gas production wells exhibit different characteristics and have different properties which could impact the performance of the chemical solutions. However, there has not been any work done on reviewing the applications of these systems for the challenging natural gas-related shutoff treatments. This study provides a comprehensive review of the laboratory evaluation and field applications of these systems used for water control in natural gas production wells and gas shutoff in oil production wells, respectively. The first part of the paper reviews the in-situ polymer gel systems, where both organically and inorganically crosslinked systems are discussed. The second part presents the water-soluble polymers with a focus on their disproportionate permeability reduction feature for controlling water in gas production wells. The review paper provides insights into the reservoir conditions, treatment design and intervention, and the success rate of the systems applied. Furthermore, the outcomes of the paper will provide knowledge regarding the limitations of the existing technologies, current challenges, and potential paths forwards

    Effect of Phosphoric Acid Anion Structure on the Corrosion Inhibition of Steel by Polyaniline

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    Conductive polymers such as polyaniline (PAni) have been examined as candidates for replacing the existing chromate systems. Protonation of emeraldine base creates polarons and bipolarons, single and paired radical cations, respectively, of higher bond energy levels within the molecular orbital band gap.\u27 For a conductive coating, considerable delocalization of corrosion charge and potential may be obtained along or between the polymer chains, because of high electron mobility. Current corrosion systems based on polyaniline typically rely on sulfuric or sulfonic acids as a dopant material, since synthetic techniques utilize persulfates as the oxidant of choice. In our experience, sulfonic/sulfuric acid systems do not produce adequate corrosion protection. However, few studies have been made of alternative dopant anions. Presumably additional studies are deemed of limited benefit because the persulfate synthesis is prevalent and time intensive purifications are required for replacing an existing sulfonic/sulfuric dopant anion. A. dopant study could yet be important to achieving a more effiCient inhibition system. Phosphonates are derivatives of phosphonic acids that contain direct phosphorous-to-carbon bonds (P-C). The P-C bonds are more resistant to hydrolysis than the P-O-C bonds of orgamc phosphates.3 Phosphonic acids are used as scale inhibitors in. Aqueous systems, the use of these acids as dopants in polyamhne could improve corrosion protection exhibited by polyaniline. Kinle.n el aL4 have reported that phosphonic acid doped polyamhne in polyvinylbutyrallatex coatings showed decreasing galvanic activity with time, providing pinhole passivation. We report testing of an Identical series of doped polyanilines as that of Kinlen, et aL applied in an epoxy polyamide coating system

    Transport And Plugging Performance Evaluation Of A Novel Re-Crosslinkable Microgel Used For Conformance Control In Mature Oilfields With Super-Permeable Channels

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    Preformed particle gels (PPG) have been widely applied in oilfields to control excessive water production. However, PPG has limited success in treating opening features because the particles can be flushed readily during post-water flooding. We have developed a novel micro-sized Re-crosslinkable PPG (micro-RPPG) to solve the problem. The microgel can re-crosslink to form a bulk gel, avoiding being washed out easily. This paper evaluates the novel microgels\u27 transport and plugging performance through super-permeable channels. Micro-RPPG was synthesized and evaluated for this study. Its storage moduli after fully swelling are approximately 82 Pa. The microgel characterization, self-healing process, transportation behavior, and plugging performance were investigated. A sandpack model with multi-pressure taps was utilized to assess the microgel dispersions\u27 transport behavior and plugging efficiency. In addition, micro-optical visualization of the gel particles was deployed to study the particle size changes before and after the swelling process. Tube tests showed that micro-RPPG could be dispersed and remain as separate particles in water with a concentration below 8,000 ppm, which is a favorable concentration for gel treatment. However, during the flooding test, the amount of microgel can be entrapped in the sandpack, resulting in a higher microgel concentration (higher than 8,000 ppm), endowing the gel particles with re-crosslinking ability even with excessive water. The microgel could propagate through the sandpack model, and the required pressure gradient mainly depends on the average particle/pore ratio and gel concentration. The gel dispersion significantly reduced channel permeability, providing sufficient resistance to post-water flooding (more than 99.97 % permeability reduction). In addition, the evaluation of micro-RPPG retention revealed that it is primarily affected by both gel concentration particle/pore ratios. We have demonstrated that the novel recrosslinkable microgel can transport through large channels, but it can provide effective plugging due to its unique re-crosslinking property. However, by this property, the new microgel exhibits enhanced stability and demonstrates resistance to being flushed out in such high-permeability environments. Furthermore, with the help of novel technology, it is possible to overcome the inherited problems commonly associated with in-situ gel treatments, including chromatographic issues, low-quality control, and shearing degradation

    Biomaterial Compositions

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    Biomaterial compositions comprising organosilicon monomers (such as silorane monomers) and chemical curing systems or dual chemical/light curing systems, in conjunction with optional tetraoxaspiro[5.5]undecanes (“TOSUs”) and/or fillers. The present invention is directed to biomaterial compositions, as well as methods for manufacturing the same, and methods of using the compositions. The biomaterial composition comprises one or more organosilicon monomers (such as a silorane) and a chemical curing system or dual chemicaVlight curing system for polymerizing the 10 monomer(s). The compositions may include one or more tetraoxaspiro[5.5]undecanes “TOSUs”) and/or fillers. Accelerators (such as photoacids), photosensitizers, and/or electron donors may also be included in the composition as appropriate

    Lysine Crosslinked Polyacrylamide─A Novel Green Polymer Gel for Preferential Flow Control

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    Acrylamide-based polymer gels have been applied to control the preferential flow in the subsurface for decades. However, some commonly used crosslinkers, such as Cr (III) and phenol-formaldehyde, are highly toxic and are being phased out because of stringent environmental regulations. This work uses l-lysine as the green crosslinker to produce acrylamide-based polymer gels. This article systematically studied the effect of lysine and polymer concentration, salinity, pH, and temperature on gelation behavior and thermal stability. Besides, the gelation mechanism and crosslinking density were elucidated in this work. A high-permeability sandstone core was used to test the plugging efficiency of this novel green gel system. This polyacrylamide/lysine system has a controllable gelation time. It can form gels at temperatures higher than 80 °C, with the gelation time from hours to days, and the elastic modulus of the gel can reach over 400 Pa. In addition, the crosslinked gels have been stable at 80 to 130 °C for over 200 days. This novel gel system could decrease rock permeability by over 1000 times. Besides, the Frrw is two times higher than the Frro, confirming that the current gel system can reduce the permeability to water more than that to oil. As a green gel system, this novel polymer gel system could replace the current toxic gel systems for the preferential fluid control for water management projects in oil and gas reservoirs, enhanced geothermal systems, and carbon capture and sequestration projects

    Comprehensive Evaluation of a High-Temperature Resistant Re-Crosslinkable Preformed Particle Gel for Water Management

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    Gel treatment has been widely applied to control conformance for improving oil recovery and control water production in mature oil fields. However, most of the hydrogel systems are limited when being applied in the harsh environments of high temperatures. A systematic evaluation was conducted in this study to evaluate a modified PPG product, the high temperature resistant re-crosslinkable preformed particle gel (HT-RPPG) which can re-crosslink to form a bulky material and keep thermostable in the large-opening features after placement. This material was developed to overcome the limitations of conventional PPGs in the reservoirs with large- opening features such as open fractures, void conduits, wormholes, and so on. The HT-RPPG can swell up to 18 times of its original size at room temperature (23˚C), and the swelling ratio is independent of brine concentration and types. We conducted a series of experiments to evaluate the effect of particle size, temperatures, swelling ratios, brine types on re-crosslinking time, as well as the gel strength, blocking performance and thermostability after re-crosslinking. Smaller particle sizes result in the HT-RPPGs swell and re-crosslink much faster. Higher temperatures increase the swelling and re-crosslinking rate, while the larger swelling ratios (more feeding brine) can slow down the re-crosslinking time. HT-RPPG re-crosslinking process can be delayed when the particles contact with Ca2+. Additionally, the re-crosslinking of HT-RPPG is a temperature-responsive reaction which can only start after reaching the target temperature of 100 °C or above. The HT-RPPG has kept its volume and strength stable at 100 to 130 °C for over 10 months so far. A blocking performance test was conducted by using the tubing model to simulate void-space conduit (VSC), and breakthrough pressure reached to 427 psi/ft

    A Novel Branched Polymer Gel System with Delayed Gelation Property for Conformance Control

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    Excessive water production from oil reservoirs not only affects the economical production of oil, but it also results in serious environmental concerns. Polymer gels have been widely applied to decrease water production and thus improve oil production. However, traditional polymer gels such as partially hydrolyzed polyacrylamide (HPAM)/chromium (III) gel systems usually have a short gelation time and cannot meet the requirement of some conformance control projects. This paper introduces a novel polymer gel system of which crosslinking time can be significantly delayed. A branched polymer grafted from arginine by the surface initiation method is synthesized as the backbone, chromium acetate is used as the crosslinker, and no additional additives are used for the gel system. The results show that the gelation time of this system can be delayed to 61 days at 45°C and 20 days at 65°C because of the rigid structure of the branched polymer and the excellent chromium (III) chelating ability of arginine. The polymer gels have been stable for more than 150 days at 45 and 65°C. Core flooding and rheology tests have demonstrated that this branched polymer has good injectivity and shear resistance in high-permeability rocks

    Dual Crosslinked Poly(acrylamide-co-N-vinylpyrrolidone) Microspheres With Re-crosslinking Ability For Fossil Energy Recovery

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    Microspheres have been proposed to be applied in controlling wastewater production for mature oilfields and migrating leakage for gas and nuclear waste storage. However, it remains challenging for stacked microspheres to maintain strong blocking ability in micron-sized small pores or fractures. In this study, a novel microsphere was developed with comprehensive properties including high deformability and long re-crosslinking time upon tunable swelling ratio for the applications. A dual covalent and physical crosslinking strategy was used to develop novel microspheres reinforced by a hydrogen bond (H-bond, between pyrrole ring and amide group) and coordination bond (between chromium acetate (CrAc) and carboxyl group via hydrolysis process). The microspheres were fabricated via radical suspension copolymerization of acrylamide (AM) and N-vinylpyrrolidone (NVP) in the presence of N, Nʹ-methylene-diacrylamide (MBA) with subsequent introduction of CrAc. MBA induced the strong crosslinking through a chemical covalent bond and H-bond triggered the weak crosslinking which was anticipated to prohibit the hydrolysis of the amide group. The H-bond delayed the formation of CrAc coordination bond by delaying the formation of carboxyl groups, resulting in achieving the re-crosslinking of the microspheres. As a result, the microspheres exhibit the tunable initial size (8–165 μm) and swelling ratio (30–630 μm), with controllable network parameters. The microspheres showed high migration ability (can transport through pores with 1/16 size of microsphere itself), and long re-crosslinking time (up to 16.5 days). The re-crosslinked gel demonstrated dual network structure with districted mesh size ζ distribution
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