Hydrate Inhibitors and Their Interferences in Corrosion Inhibition

Seo, Yutaek

doi:10.1002/9783527822140.ch17

Cited by 5 publications

(9 citation statements)

References 35 publications

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“…The simultaneous injection of various oilfield reagents into a multiphase flow of formation fluids often leads to a decrease in their target properties or the occurrence of side effects. One of the reasons for such behavior is the interaction of these reagents with each other and/or with other flow components [6][7][8][9][10][11]. The injection of large quantities of oilfield reagents requires a more powerful infrastructure (additional storage tanks, injection pumps, and distribution pipelines) and a complex process of the additives regeneration [12].…”

Section: Introductionmentioning

confidence: 99%

Performance of Waterborne Polyurethanes in Inhibition of Gas Hydrate Formation and Corrosion: Influence of Hydrophobic Fragments

et al. 2020

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The design of new dual-function inhibitors simultaneously preventing hydrate formation and corrosion is a relevant issue for the oil and gas industry. The structure-property relationship for a promising class of hybrid inhibitors based on waterborne polyurethanes (WPU) was studied in this work. Variation of diethanolamines differing in the size and branching of N-substituents (methyl, n-butyl, and tert-butyl), as well as the amount of these groups, allowed the structure of polymer molecules to be preset during their synthesis. To assess the hydrate and corrosion inhibition efficiency of developed reagents pressurized rocking cells, electrochemistry and weight-loss techniques were used. A distinct effect of these variables altering the hydrophobicity of obtained compounds on their target properties was revealed. Polymers with increased content of diethanolamine fragments with n- or tert-butyl as N-substituent (WPU-6 and WPU-7, respectively) worked as dual-function inhibitors, showing nearly the same efficiency as commercial ones at low concentration (0.25 wt%), with the branched one (tert-butyl; WPU-7) turning out to be more effective as a corrosion inhibitor. Commercial kinetic hydrate inhibitor Luvicap 55 W and corrosion inhibitor Armohib CI-28 were taken as reference samples. Preliminary study reveals that WPU-6 and WPU-7 polyurethanes as well as Luvicap 55 W are all poorly biodegradable compounds; BODt/CODcr (ratio of Biochemical oxygen demand and Chemical oxygen demand) value is 0.234 and 0.294 for WPU-6 and WPU-7, respectively, compared to 0.251 for commercial kinetic hydrate inhibitor Luvicap 55 W. Since the obtained polyurethanes have a bifunctional effect and operate at low enough concentrations, their employment is expected to reduce both operating costs and environmental impact.

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Section: Introductionmentioning

confidence: 99%

Performance of Waterborne Polyurethanes in Inhibition of Gas Hydrate Formation and Corrosion: Influence of Hydrophobic Fragments

et al. 2020

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“…These include corrosion, scale, and gas hydrates. − For most flow lines, operators choose to combat these issues with one or more chemical inhibitors. Co-injection of these inhibitors can present its own set of compatibility problems, including formulating several inhibitors to be stable and pumpable as a single fluid and the possibility of one inhibitor lowering the performance of another. − Some compatible blends have been found, but there is scope for improvement …”

Section: Introductionmentioning

confidence: 99%

Multi-functional Flow Assurance Chemicals: Corrosion and Kinetic Hydrate Inhibition from Maleic Anhydride:N-Vinyl Caprolactam Copolymers and Synergists

et al. 2023

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Water-based flow assurance issues include corrosion, scale, and gas hydrate formation. Chemical solutions to mitigate these issues usually require separate inhibitors, which sometimes can lead to compatibility difficulties. Herein, we report studies on maleic-based copolymers to combat hydrate and corrosion with a view to optimizing for scale inhibition also. The product of maleic anhydride:N-vinyl caprolactam copolymer reacted with 3-dibutylaminopropylamine (MA:VCap-DBAPA) and its amine oxide derivative (MA:VCap-DBAPA-AO) were the kinetic hydrate inhibitor (KHI) polymers investigated. Due to limited CO2 corrosion inhibition (CI) by the polymers alone, various oxygen-, sulfur-, and nitrogen-based additives were screened for improved CO2 CI and possible KHI synergy. KHI performance screening tests were conducted under high pressure with a structure II-forming natural gas mixture in steel rocking cells using the slow (1 °C/h) constant cooling method. CO2 corrosion inhibition was measured by linear polarization resistance in a stirred 1 L CO2 bubble test apparatus using C1018 steel coupons and 3.6 wt % brine at 20.5 °C. Several sulfur-based additives improved the CI efficiency of the maleic polymers, especially butyl thioglycolate and 2-aminoethanethiol, without a negative effect on the KHI performance. For example, 2500 ppm MA:VCap-DBAPA plus 1000 ppm butyl thioglycolate gave an average hydrate onset temperature (T o) of 4.4 °C (12.7 °C below the T o for no additive) and 99.7% CI efficiency. In contrast to a classic fatty acid imidazoline surfactant corrosion inhibitor, butyl thioglycolate was also found to greatly enhance the CI efficiency of industrial KHIs, poly(N-vinyl caprolactam) (PVCap) and N-vinyl pyrrolidone:N-vinyl caprolactam copolymer, with no antagonism to the KHI performance of the polymer. In addition, butyl thioglycolate boosted the KHI performance of PVCap. The use of small synergists such as butyl thioglycolate avoids the use of classical surfactant corrosion inhibitors which can lead to tighter emulsions and poor overboard oil-in-water quality.

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“…29,30 CIs have the ability to create a protective film on metal surfaces by adsorption and then retard the corrosion rate of the metal. 31 For instance, the film-forming CIs usually used to reduce CO 2 corrosion in pipelines are organic compounds that usually contain nitrogen and a long hydrocarbon tail. 32,33 Therefore, the CIs and KHIs probably coexist in the oil and gas transportation pipelines, where compatibility problems could occur when different types of inhibitors are applied together.…”

Section: Introductionmentioning

confidence: 99%

“…Corrosion and/or hydrate formation tend to cause submerged gas pipelines to fail through leakage or full bore rupture. , During the process of hydrate formation, hydrate composition will interact with the inner surface of the pipeline and finally generate a reaction that initiates internal corrosion . To prevent corrosion damage, many ways have been proposed, such as blending of production fluids, upgrading materials, chemical inhibition, and process control, among which corrosion inhibitors (CIs) are extensively used as one of the best-known methods for corrosion protection in industry. , CIs have the ability to create a protective film on metal surfaces by adsorption and then retard the corrosion rate of the metal . For instance, the film-forming CIs usually used to reduce CO 2 corrosion in pipelines are organic compounds that usually contain nitrogen and a long hydrocarbon tail. , Therefore, the CIs and KHIs probably coexist in the oil and gas transportation pipelines, where compatibility problems could occur when different types of inhibitors are applied together. , Thus, it is of great significance to consider the influence of CIs on hydrate formation and the inhibition capacity of KHIs.…”

Section: Introductionmentioning

confidence: 99%

Experimental Investigation of the Weakening Effect of Corrosion Inhibitors on the Performance of Kinetic Hydrate Inhibitors

Yang,

Chen,

Zou

et al. 2023

Energy Fuels

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Gas hydrate blockage and metal corrosion are both crucial flow assurance issues in the oil and gas transportation pipelines, and kinetic hydrate inhibitors (KHIs) and corrosion inhibitors (CIs) are commonly used to deal with the challenges. In this study, the effect of four CIs and the mixed inhibitor formulation of CIs and KHIs were both studied on the kinetics of methane−propane hydrate formation, while interfacial tension and zeta potential characterization were conducted to deeply investigate the interactions between CI and KHI fractions. Results demonstrated that the CI applied in experiments all had a limited impact on hydrate growth at low concentrations but possessed various effects at higher concentrations, which were closely related to the type of CI. When mixed with KHI, CI with a high concentration can effectively weaken the inhibition performance of KHI, while the overall inhibition capacity of the mixed inhibitor formulation on hydrate formation was not the simple sum of the single CI and single KHI. The weakening effect of the selected CI on KHI was attributed to two mechanism hypotheses. On the one hand, CI might compete with KHI in the areas where KHI mainly acts to inhibit hydrate formation, such as the gas−liquid interface and the adsorption sites near the hydrate surface. On the other hand, KHI molecules can combine with CI molecules through electrostatic attraction when the electronegativity of a mixed inhibitor formulation is opposite that of a single KHI, which probably results in the loss of inhibition function of these KHI molecules on hydrate formation. The overall results also indicated that water-soluble imidazolinamide was a potentially applicable CI that can be used together with KHIs because of their good compatibility in inhibiting hydrate formation.

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Hydrate Inhibitors and Their Interferences in Corrosion Inhibition

Cited by 5 publications

References 35 publications

Performance of Waterborne Polyurethanes in Inhibition of Gas Hydrate Formation and Corrosion: Influence of Hydrophobic Fragments

Performance of Waterborne Polyurethanes in Inhibition of Gas Hydrate Formation and Corrosion: Influence of Hydrophobic Fragments

Multi-functional Flow Assurance Chemicals: Corrosion and Kinetic Hydrate Inhibition from Maleic Anhydride:N-Vinyl Caprolactam Copolymers and Synergists

Experimental Investigation of the Weakening Effect of Corrosion Inhibitors on the Performance of Kinetic Hydrate Inhibitors

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