The Experts below are selected from a list of 252 Experts worldwide ranked by ideXlab platform
Malcolm A Kelland - One of the best experts on this subject based on the ideXlab platform.
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additives for Kinetic Hydrate Inhibitor formulations to avoid polymer fouling at high injection temperatures part 2 experimental studies with denaturants osmolytes ionic liquids and surfactants
Energy & Fuels, 2020Co-Authors: Malcolm A Kelland, Johnsigvard NjauAbstract:Injection of Kinetic Hydrate Inhibitor (KHI) polymers can cause fouling problems if the polymer solution has a deposition temperature below the well head temperatures. In Part 1 of this 3-part seri...
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additives for Kinetic Hydrate Inhibitor formulations to avoid polymer fouling at high injection temperatures part 1 a review of possible methods
Energy & Fuels, 2020Co-Authors: Malcolm A KellandAbstract:The main ingredient in Kinetic Hydrate Inhibitor (KHI) formulations is a water-soluble polymer with both hydrophobic and hydrophilic moieties. Many of these KHI polymers have low cloud point (Tcl) and deposition point (Tdp) temperatures. Tdp is often not much higher than Tcl. The low Tdp value can cause unwanted polymer deposition when solutions of the polymers are injected into a hot aqueous well stream, especially high salinity produced fluids, which will impact the KHI performance. One way to overcome this problem is to copolymerise the active functional monomers with more hydrophilic monomers. However, this can often cause reduced KHI performance. Previous studies have shown that low Tcl for a polymer could be beneficial for the KHI performance if certain other criteria are met. In this Part I of our study we review possible methods to raise the Tdp (and maybe also the Tcl) of a KHI polymer with low Tcl by formulating it with a second additive. The methods include the use of solvents, hydrotropes, cla...
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Polyvinylsulfonamides as Kinetic Hydrate Inhibitors
Energy & Fuels, 2020Co-Authors: Qian Zhang, Malcolm A Kelland, Hiroharu AjiroAbstract:Kinetic Hydrate Inhibitor (KHI) polymers have been used for over 25 years to prevent gas Hydrate formation in oil and gas production flow lines. KHI polymers are water-soluble at Hydrate formation conditions and most of them contain amide (-NH-C(=O)-) functional groups. The water-solubility is due to their strong hydrophilicity and hydrogen-bonding ability. In this report we have investigated various classes of polyvinylsulfonamides as KHIs for the first time. The carbonyl moiety in the amide group can be replaced with the sulfonyl moiety to give the isosteric sulfonamide group (-NH-S(=O)2-) which has 2 oxygen atoms. Like amides, the hydrogen atoms in sulfonamides are relatively acidic because the charge formed in the conjugate base can be stabilized by resonance. In addition, sulfonamides are not easily hydrolyzed under hot acidic conditions, a problem that is known for some polyamide KHIs which can affect their performance in the field. Here we report the synthesis and KHI performance of a range of poly...
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solvent synergists for improved Kinetic Hydrate Inhibitor performance of poly n vinylcaprolactam
Energy & Fuels, 2020Co-Authors: Malcolm A Kelland, Erik Gisle DirdalAbstract:The synergetic effect of a range of different solvents on the Kinetic Hydrate Inhibitor (KHI) performance of poly(N-vinylcaprolactam) (PVCap) has been investigated. The equipment used was a high-pr...
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investigation of solvent synergists for improved Kinetic Hydrate Inhibitor performance of poly n isopropyl methacrylamide
Energy & Fuels, 2019Co-Authors: Malcolm A KellandAbstract:The synergistic effect of a range of solvents on the Kinetic Hydrate Inhibitor (KHI) performance of poly(N-isopropyl methacrylamide) (PNIPMAm) has been investigated in slow (ca. 1 °C/h) constant cooling high-pressure (76 bar) rocking cell experiments using a structure II forming synthetic natural gas mixture. We have tested the synergistic effects of several monoglycol ethers and compared them to those of corresponding diglycol ethers and alcohols. Compounds containing lactate, carboxylate, ammonium, and pyrrolidone headgroups have also been investigated as synergists. In general the monoglycol ethers were found to function best as synergists with PNIPMAm, and the performance improved going from n-butyl to isobutyl, cyclopentyl, and cyclohexyl alkyl substituents. The best performing synergist in this study was found to be 2-(cyclohexyloxy)ethanol (CHexGE). Addition of 5000 ppm CHexGE to 2500 ppm PNIPMAm-II (made in isopropyl alcohol and precipitated out, Mn = 8100 g/mol) dropped To from 6.8 °C for pure po...
Luca Del Villano - One of the best experts on this subject based on the ideXlab platform.
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an investigation into the Kinetic Hydrate Inhibitor properties of two imidazolium based ionic liquids on structure ii gas Hydrate
Chemical Engineering Science, 2010Co-Authors: Luca Del Villano, Malcolm A KellandAbstract:Abstract Kinetic Hydrate Inhibitors (KHIs) are used to prevent gas Hydrate formation in gas and oilfield operations. All KHIs discovered to date are water-soluble polymers. However, their performance can be enhanced by certain non-polymeric organic molecules. Recently, it was claimed that certain imidazolium-based ionic liquids could have a dual function, acting as both thermodynamic Inhibitors and KHIs (Xiao, C., Adidharma, H., 2009. Chem. Eng. Sci . 64, 1522). As the KHI experimental work was carried out at a temperature of –12 °C, giving a very high subcooling of about 25 °C, we reinvestigated two of these ionic liquids at more typical subsea temperatures and subcoolings. We find that these ionic liquids are very poor KHIs when used alone at 5000–10000 ppm, but they are fairly good synergists for commercial KHIs based on vinyl lactam polymers and hyperbranched poly(ester amide)s. Both ionic liquids showed only weak growth inhibition of tetrahydrofuran Hydrate crystals. Finally, both ionic liquids were poorly biodegraded in the OECD306 seawater 28 day biodegradation test.
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a study of the Kinetic Hydrate Inhibitor performance and seawater biodegradability of a series of poly 2 alkyl 2 oxazoline s
Energy & Fuels, 2009Co-Authors: Luca Del Villano, Roald Kommedal, Martin W.m. Fijten, Richard Hoogenboom, Ulrich S. Schubert, Malcolm A KellandAbstract:Kinetic Hydrate Inhibitors (KHIs) have been used successfully in the field for about the last 14 years to prevent gas Hydrate formation mostly in gas and oilfield production lines. They work by delaying the nucleation and often also the growth of gas Hydrate crystals for periods of time dependent on the subcooling in the system. Poly(2-alkyl-2-oxazoline)s [or poly(N-acylalkylene imine)s] are a known class of KHI, but no work has previously been published detailing a systematic study of structure versus performance. In this paper we report the KHI performance of poly(2-alkyl-2-oxazoline) homopolymers and statistical copolymers with alkyl side groups up to four carbon atoms. The study includes Hydrate crystal growth tests on structure II tetrahydrofuran Hydrate crystals as well as high pressure nucleation and crystal growth studies on a synthetic natural gas mixture giving structure II Hydrates. Seawater biodegradation studies on all the polymers according to the OECD306 procedure indicate that they are all...
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A study of the Kinetic Hydrate Inhibitor performance and seawater biodegradability of a series of poly(2-alkyl-2-oxazoline)s
Energy and Fuels, 2009Co-Authors: Luca Del Villano, Roald Kommedal, Martin W.m. Fijten, Richard Hoogenboom, Ulrich S. Schubert, Malcolm A KellandAbstract:Kinetic Hydrate Inhibitors (KHIs) have been used successfully in the field for about the last 14 years to prevent gas Hydrate formation mostly in gas and oilfield production lines. They work by delaying the nucleation and often also the growth of gas Hydrate crystals for periods of time dependent on the subcooling in the system. Poly(2-alkyl-2-oxazoline)s [or poly(N-acylalkylene imine)s] are a known class of KHI, but no work has previously been published detailing a systematic study of structure versus performance. In this paper we report the KHI performance of poly(2-alkyl-2-oxazoline) homopolymers and statistical copolymers with alkyl side groups up to four carbon atoms. The study includes Hydrate crystal growth tests on structure II tetrahydrofuran Hydrate crystals as well as high pressure nucleation and crystal growth studies on a synthetic natural gas mixture giving structure II Hydrates. Seawater biodegradation studies on all the polymers according to the OECD306 procedure indicate that they are all poorly biodegradable (
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Class of Kinetic Hydrate Inhibitors with Good Biodegradability
Energy & Fuels, 2008Co-Authors: Luca Del Villano, Roald Kommedal, Malcolm A KellandAbstract:Kinetic Hydrate Inhibitors have been used successfully in the field for about the last 13 years to prevent gas Hydrate formation mostly in gas- and oilfield production lines. They work by delaying the nucleation and often also the growth of gas Hydrate crystals for periods of time dependent upon the subcooling in the system. Current commercial Kinetic Hydrate Inhibitors are used for field applications where the subcooling is as high as about 10 °C. In the Norwegian sector of the North Sea, very few of the commercial Kinetic Hydrate Inhibitors are available for use offshore because of poor environmental properties usually related to biodegradability. We have designed and synthesized a class of Kinetic Hydrate Inhibitor, which appears to show good biodegradability (OECD306, >20% in 28 days). Inhibitor performance tests have been carried out in stirred autoclaves (titanium and sapphire) using a natural gas blend and saline water giving structure II Hydrates. In the presence of solvents, we have obtained a fa...
Xuemei Lang - One of the best experts on this subject based on the ideXlab platform.
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recovery of monoethylene glycol combined with Kinetic Hydrate Inhibitor
Chemical Engineering Science, 2017Co-Authors: Shurui Xu, Yanhong Wang, Xuemei LangAbstract:Abstract Kinetic Hydrate Inhibitors (KHIs) combined with thermodynamic Inhibitors (THIs) such as monoethylene glycol (MEG) have been good additives for the prevention of Hydrate blockages in oil and gas industry operations. The regeneration and recycling of MEG are conventional process steps used to reduce costs. However, the recovery of THIs in the presence of KHIs or the recovery of the KHIs alone has rarely been investigated. In this paper, a series of experiments was designed to study the recovery of both a KHI based poly (N-vinylcaprolactam) and MEG. The results showed that the MEG recovery rate was closely related to the recovery temperature, but was not influenced by the KHI. The MEG recovery rate from solutions consisting of MEG and the KHI was as high as 94.52%, and the KHI was recovered along with the MEG. The polymer structure of the KHI was rarely changed when the recovery temperature was close to its polymerization temperature. The presence of the KHI had a negative impact on the thermodynamic inhibition efficiency of the MEG. The KHI performance of the recovered solution obtained at the KHI polymerization temperature could reach the level of the fresh combination Inhibitor, but the recovered solutions obtained at temperatures far above the KHI polymerization temperature demonstrated worse Inhibitory performance. The Kinetic performance could be restored by adding 5.0 wt% fresh MEG. MEG enabled a subcooling temperature decrease into the range in which KHI which could play its role effectively, leading to the improved Kinetic performance of the recovered solution.
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pectin as an extraordinary natural Kinetic Hydrate Inhibitor
Scientific Reports, 2016Co-Authors: Shurui Xu, Yanhong Wang, Xuemei Lang, Songtian Fang, Jun ChenAbstract:Pectin as a novel natural Kinetic Hydrate Inhibitor, expected to be eco-friendly and sufficiently biodegradable, was studied in this paper. The novel crystal growth inhibition (CGI) and standard induction time methods were used to evaluate its effect as Hydrate Inhibitor. It could successfully inhibit methane Hydrate formation at subcooling temperature up to 12.5 °C and dramatically slowed the Hydrate crystal growth. The dosage of pectin decreased by 66% and effective time extended 10 times than typical Kinetic Inhibitor. Besides, its maximum growth rate was no more than 2.0%/h, which was far less than 5.5%/h of growth rate for PVCap at the same dosage. The most prominent feature was that it totally inhibited methane Hydrate crystal rapid growth when Hydrate crystalline occurred. Moreover, in terms of typical natural Inhibitors, the inhibition activity of pectin increased 10.0-fold in induction time and 2.5-fold in subcooling temperature. The extraordinary inhibition activity is closely related to its hydrogen bonding interaction with water molecules and the hydrophilic structure. Finally, the biodegradability and economical efficiency of pectin were also taken into consideration. The results showed the biodegradability improved 75.0% and the cost reduced by more than 73.3% compared to typical commercial Kinetic Inhibitors.
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Kinetic Hydrate Inhibitor performance of new copolymer poly n vinyl 2 pyrrolidone co 2 vinyl pyridine s with tbab
Journal of Natural Gas Chemistry, 2012Co-Authors: Jun Hu, Yanhong Wang, Xuemei Lang, Sijia Li, Qingping LiAbstract:Abstract In oil and gas field, the application of Kinetic Hydrate Inhibitors (KHIs) independently has remained problematic in high subcooling and high water-cut situation. One feasible method to resolve this problem is the combined use of KHIs and some synergists, which would enhance KHIs' Inhibitory effect on both Hydrate nucleation and Hydrate crystal growth. In this study, a novel kind of KHI copolymer poly(N-vinyl-2-pyrrolidone-co-2-vinyl pyridine)s (HGs) is used in conjunction with TBAB to show its high performance on Hydrate inhibition. The performance of HGs with different monomer ratios in structure II tetrahydrofuran (THF) Hydrate is investigated using Kinetic Hydrate Inhibitor evaluation apparatus by step-cooling method and isothermal cooling method. With the combined gas Hydrate Inhibitor at the concentration of 1.0 wt%, the induction time of 19 wt% THF solution could be prolonged to 8.5 h at a high subcooling of 6 °C. Finally, the mechanism of HGs inhibiting the formation of gas Hydrate is proposed.
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Kinetic Hydrate Inhibitor performance of new copolymer poly（N-vinyl-2-pyrrolidone-co-2-vinyl pyridine）s with TBAB
Journal of Natural Gas Chemistry, 2012Co-Authors: Jun Hu, Yanhong Wang, Xuemei Lang, Sijia Li, Qingping LiAbstract:Abstract In oil and gas field, the application of Kinetic Hydrate Inhibitors (KHIs) independently has remained problematic in high subcooling and high water-cut situation. One feasible method to resolve this problem is the combined use of KHIs and some synergists, which would enhance KHIs' Inhibitory effect on both Hydrate nucleation and Hydrate crystal growth. In this study, a novel kind of KHI copolymer poly(N-vinyl-2-pyrrolidone-co-2-vinyl pyridine)s (HGs) is used in conjunction with TBAB to show its high performance on Hydrate inhibition. The performance of HGs with different monomer ratios in structure II tetrahydrofuran (THF) Hydrate is investigated using Kinetic Hydrate Inhibitor evaluation apparatus by step-cooling method and isothermal cooling method. With the combined gas Hydrate Inhibitor at the concentration of 1.0 wt%, the induction time of 19 wt% THF solution could be prolonged to 8.5 h at a high subcooling of 6 °C. Finally, the mechanism of HGs inhibiting the formation of gas Hydrate is proposed.
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synthesis and application of a novel combined Kinetic Hydrate Inhibitor
Science China-technological Sciences, 2011Co-Authors: Jun Hu, Yanhong Wang, Xuemei Lang, Juan Du, Qingping LiAbstract:In oil and gas exploration and transportation, low dosage Hydrate Inhibitors (LDHIs) are more favorably utilized to inhibit the formation of Hydrates than thermodynamic Inhibitors (THs) as a trend. However, there are no industrial products of LDHIs available domestically, and the corresponding application experience is in urgent need. In this paper, a combined Hydrate Inhibitor (HY-1) was synthesized after a series of reaction condition optimization, and its performance on THF Hydrate inhibition was investigated using Kinetic Hydrate Inhibitor evaluation apparatus with 6 cells bathing in air. The results show that when the reaction temperature is 60°C, the reaction time is 6 h, and the monomer: solvent ratio is 1:2, the product has the best Kinetic Hydrate Inhibitor performance on THF Hydrate. On these bases, the scale-up production of this combined Hydrate Inhibitor was carried out. Although the scale-up product (HY-10) performs less effectively on the THF Hydrate inhibition than HY-1, it functions better than a commercial product (Inhibex501) during in-house tests. HY-10 was successfully applied to the gas production process. Field trials in northern Shaanxi PetroChina Changqing Oilfield Company (PCOC) show that 2 wt% of HY-10 is effective on natural gas Hydrate inhibition. It is found through economic analysis that the use of HY-10 has obvious economical advantage over methanol and Inhibex501.
Martin W.m. Fijten - One of the best experts on this subject based on the ideXlab platform.
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a study of the Kinetic Hydrate Inhibitor performance and seawater biodegradability of a series of poly 2 alkyl 2 oxazoline s
Energy & Fuels, 2009Co-Authors: Luca Del Villano, Roald Kommedal, Martin W.m. Fijten, Richard Hoogenboom, Ulrich S. Schubert, Malcolm A KellandAbstract:Kinetic Hydrate Inhibitors (KHIs) have been used successfully in the field for about the last 14 years to prevent gas Hydrate formation mostly in gas and oilfield production lines. They work by delaying the nucleation and often also the growth of gas Hydrate crystals for periods of time dependent on the subcooling in the system. Poly(2-alkyl-2-oxazoline)s [or poly(N-acylalkylene imine)s] are a known class of KHI, but no work has previously been published detailing a systematic study of structure versus performance. In this paper we report the KHI performance of poly(2-alkyl-2-oxazoline) homopolymers and statistical copolymers with alkyl side groups up to four carbon atoms. The study includes Hydrate crystal growth tests on structure II tetrahydrofuran Hydrate crystals as well as high pressure nucleation and crystal growth studies on a synthetic natural gas mixture giving structure II Hydrates. Seawater biodegradation studies on all the polymers according to the OECD306 procedure indicate that they are all...
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A study of the Kinetic Hydrate Inhibitor performance and seawater biodegradability of a series of poly(2-alkyl-2-oxazoline)s
Energy and Fuels, 2009Co-Authors: Luca Del Villano, Roald Kommedal, Martin W.m. Fijten, Richard Hoogenboom, Ulrich S. Schubert, Malcolm A KellandAbstract:Kinetic Hydrate Inhibitors (KHIs) have been used successfully in the field for about the last 14 years to prevent gas Hydrate formation mostly in gas and oilfield production lines. They work by delaying the nucleation and often also the growth of gas Hydrate crystals for periods of time dependent on the subcooling in the system. Poly(2-alkyl-2-oxazoline)s [or poly(N-acylalkylene imine)s] are a known class of KHI, but no work has previously been published detailing a systematic study of structure versus performance. In this paper we report the KHI performance of poly(2-alkyl-2-oxazoline) homopolymers and statistical copolymers with alkyl side groups up to four carbon atoms. The study includes Hydrate crystal growth tests on structure II tetrahydrofuran Hydrate crystals as well as high pressure nucleation and crystal growth studies on a synthetic natural gas mixture giving structure II Hydrates. Seawater biodegradation studies on all the polymers according to the OECD306 procedure indicate that they are all poorly biodegradable (
Richard Hoogenboom - One of the best experts on this subject based on the ideXlab platform.
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a study of the Kinetic Hydrate Inhibitor performance and seawater biodegradability of a series of poly 2 alkyl 2 oxazoline s
Energy & Fuels, 2009Co-Authors: Luca Del Villano, Roald Kommedal, Martin W.m. Fijten, Richard Hoogenboom, Ulrich S. Schubert, Malcolm A KellandAbstract:Kinetic Hydrate Inhibitors (KHIs) have been used successfully in the field for about the last 14 years to prevent gas Hydrate formation mostly in gas and oilfield production lines. They work by delaying the nucleation and often also the growth of gas Hydrate crystals for periods of time dependent on the subcooling in the system. Poly(2-alkyl-2-oxazoline)s [or poly(N-acylalkylene imine)s] are a known class of KHI, but no work has previously been published detailing a systematic study of structure versus performance. In this paper we report the KHI performance of poly(2-alkyl-2-oxazoline) homopolymers and statistical copolymers with alkyl side groups up to four carbon atoms. The study includes Hydrate crystal growth tests on structure II tetrahydrofuran Hydrate crystals as well as high pressure nucleation and crystal growth studies on a synthetic natural gas mixture giving structure II Hydrates. Seawater biodegradation studies on all the polymers according to the OECD306 procedure indicate that they are all...
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A study of the Kinetic Hydrate Inhibitor performance and seawater biodegradability of a series of poly(2-alkyl-2-oxazoline)s
Energy and Fuels, 2009Co-Authors: Luca Del Villano, Roald Kommedal, Martin W.m. Fijten, Richard Hoogenboom, Ulrich S. Schubert, Malcolm A KellandAbstract:Kinetic Hydrate Inhibitors (KHIs) have been used successfully in the field for about the last 14 years to prevent gas Hydrate formation mostly in gas and oilfield production lines. They work by delaying the nucleation and often also the growth of gas Hydrate crystals for periods of time dependent on the subcooling in the system. Poly(2-alkyl-2-oxazoline)s [or poly(N-acylalkylene imine)s] are a known class of KHI, but no work has previously been published detailing a systematic study of structure versus performance. In this paper we report the KHI performance of poly(2-alkyl-2-oxazoline) homopolymers and statistical copolymers with alkyl side groups up to four carbon atoms. The study includes Hydrate crystal growth tests on structure II tetrahydrofuran Hydrate crystals as well as high pressure nucleation and crystal growth studies on a synthetic natural gas mixture giving structure II Hydrates. Seawater biodegradation studies on all the polymers according to the OECD306 procedure indicate that they are all poorly biodegradable (
