Publications by authors named "Malcolm A Kelland"

Harsh scale buildup, such as calcium carbonate (calcite) and barium sulfate (barite), poses significant challenges in the oil and gas industry. While various scale inhibitors (SIs) are employed to mitigate this issue, there is a need for greener, more efficient, compatible, and affordable alternatives. Calcium compatibility often complicates the use of SIs, potentially leading to formation damage.

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Current commercial kinetic hydrate inhibitors (KHIs) are all based on water-soluble polymers with amphiphilic alkylamide or lactam groups. The size and shape of the hydrophobic moiety are known to be critical for optimum KHI performance. Proteins and peptides represent an environmentally friendly alternative, especially as bioengineering could be used to manufacture a product predetermined to have optimum KHI performance.

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Deposition of inorganic scales in wells, flow lines, and equipment is a major problem in the water treatment, geothermal, or upstream oil and gas industries. Deployment of scale inhibitors has been adopted worldwide for oilfield scale prevention. Commercial synthetic scale inhibitors such as polymeric carboxylates and sulfonates or nonpolymeric phosphonates offer good scale inhibition performance but often suffer from one or more limitations including biodegradability, calcium compatibility, and thermal stability.

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Kinetic hydrate inhibitors (KHIs) are a chemical method of preventing gas hydrate plugging of oil and gas production flow lines. The main ingredient in a KHI formulation is one or more water-soluble amphiphilic polymers. Poly(-vinyl caprolactam) (PVCap) is an unbranched polymer and a well-known industrial KHI, often used as a yardstick to compare the performance of new polymers.

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Kinetic gas hydrate inhibitors (KHIs) are often used in combination with film-forming corrosion inhibitors (CIs) in oilfield production flow lines. However, CIs can be antagonistic to KHI performance. In this study, maleic anhydride---isopropylmethacrylamide copolymer (MA:NIPMAM) and its derivatives were successfully synthesized and tested for gas hydrate and corrosion inhibition.

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Kinetic hydrate inhibitors (KHIs) are used to prevent deposits and plugging of oil and gas production flow lines by gas hydrates. The key ingredient in a KHI formulation is a water-soluble amphiphilic polymer. Recently, polymers of a new commercially available 5-ring vinylic monomer 5-methyl-3-vinyl-2-oxazolidinone (VMOX) were investigated as KHIs and shown to perform better than some commercial KHI polymers such as poly(-vinyl pyrrolidone).

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Gas hydrate anti-agglomerants (AAs) are a class of low-dosage hydrate inhibitor that are used to prevent plugging of gas hydrates in oil and condensate upstream flow lines. Industrial AAs are mostly cationic surfactants which are "hydrate-philic", i.e.

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Scale inhibitors are an extremely important chemical in upstream oil and gas field operations and water treatment industries. These inhibitors prevent nucleation and/or crystal growth of scales such as calcite and barite. This keeps the pipes and other equipment and surfaces free from deposits, allowing the maximum flow of aqueous fluids.

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Kinetic hydrate inhibitors (KHIs) are applied in oil and gas fields to prevent gas hydrate formation, most often in cold subsea flow lines. The main component in industrial KHI formulations is a water-soluble polymer with many amphiphilic groups of which the hydrophilic part is most commonly the amide functional group. In the last decade, we have investigated polyamine oxides as alternatives to polyamides due to the strong hydrogen bonding of the amine oxide group.

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The deployment of kinetic hydrate inhibitors (KHIs) is a chemical method for the prevention of gas hydrate plugging in gas, condensate, and oil production flow lines. Polymers made using the monomer -vinylcaprolactam (VCap) are one of the most common KHI classes. Alternative classes of polymers containing caprolactam groups are rare.

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The use of kinetic hydrate inhibitors (KHIs) is a well-known method for preventing gas hydrate formation in oil and gas production flow lines. The main ingredient in KHI formulations is one or more polymers with amphiphilic groups. Here, we report a series of citramide-based nonpolymeric KHIs.

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Water-soluble amphiphilic polymers are vital chemicals in the oil and gas industry to retard crystal growth of hydrocarbon hydrate surface adsorption and suppress nucleation of a pristine hydrate nucleus, thereby preventing formation of hydrate blockages in flow lines during oil and natural gas production. Apart from a few theoretical modeling studies, an experimental method to study the polymer/water interface in the crystal growth is critically needed. Here, water motions in the hydration shells of an exemplary kinetic inhibitor, poly(-vinylcaprolactam), during hydrate formation from the tetrahydrofuran/water system are revealed via nuclear magnetic resonance relaxometry.

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Amphiphilic polymers have now been designed to achieve an icephobic performance and have been used for ice adhesion prevention. They may function by forming a strongly bonded but nonfreezable water shell which serves as a self-lubricating interfacial layer that weakens the adhesion strength between ice and the surface. Here, an analogous concept is built to prevent the formation of clathrate hydrate compounds during oil and natural gas production, in which amphiphilic water-soluble polymers act as efficient kinetic hydrate inhibitors (KHIs).

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Kinetic hydrate inhibitors (KHIs) have been used for over 25 years to prevent gas hydrate formation in oil and gas production flow lines. The main component in KHI formulations is a water-soluble polymer with many amphiphilic groups, usually made up of amide groups and adjacent hydrophobic groups with 3-6 carbon atoms. KHI polymers are one of the most expensive oilfield production chemicals.

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Polymers containing amide groups have been used as kinetic hydrate inhibitors (KHIs). The amide group has good performance for hydrate nucleus adsorption, resulting in inhibition of hydrate growth. Polyisocyanates composed of an amide backbone can be KHI candidates; however, the use of polyisocyanates as KHIs has not yet been reported.

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Organophosphorous compounds are still widely used as potential scale inhibitors in the upstream oil and gas industry, particularly in squeeze treatments as they have good adsorption properties on rock and are easily detectable. However, most phosphonate-based scale inhibitors have some drawbacks, such as poor biodegradability and various incompatibilities with the production system. The low toxicity of bisphosphonates motivated us to test a series of aliphatic and aromatic hydroxybisphosphonates as new oilfield scale inhibitors for calcium carbonate (calcite) and barium sulfate (barite) scales.

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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 -substituents (methyl, -butyl, and -butyl), as well as the amount of these groups, allowed the structure of polymer molecules to be preset during their synthesis.

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Water tightly bound to the kinetic inhibitors of tetrahydrofuran hydrate and natural gas hydrate has a relaxation time scale of sub-milliseconds. The amounts of such water are related to the inhibition time before rapid growth of the hydrate crystals and the hydrophobic hydration effect of the inhibitors.

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Tetraisohexylammonium bromide [systematic name: tetrakis(4-methylpentyl)azanium bromide], C(24)H(52)N(+)·Br(-), is a powerful structure II clathrate hydrate crystal-growth inhibitor. The crystal structure, in the space group P3(2)21, contains one ammonium cation and one bromide anion in the asymmetric unit, both on general positions. At 100 K, the ammonium cation exhibits one ordered isohexyl chain and three disordered isohexyl chains.

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