Abstract: A method of inhibiting or retarding formation of hydrates from water and a lower alkane, such as methane or ethane, involves adding additives which comprise (i) a corrosion inhibitor and (ii) a salt which is of formula [R.sup.1 (R.sup.2)XR.sup.3 ].sup.+ Y.sup.-, wherein each of R.sup.1, R.sup.2 and R.sup.3 is bonded directly to X, each of R.sup.1 and R.sup.2, which may be the same or different is an alkyl group of at least 4 carbons, X is S, NR.sup.4 or PR.sup.4, wherein each of R.sup.3 and R.sup.4 which may be the same or different represents hydrogen or an organic group, with the proviso that at least one of R.sup.3 and R.sup.4 is an organic group of at least 4 carbons, and Y is an anion, the additives being added in an amount effective to inhibit or retard hydrate formation, to a medium susceptible to hydrate formation.

Abstract: A method for inhibiting the formation of clathrate hydrates in a fluid having hydrate forming constituents is claimed. More specifically, the method can be used in treating a petroleum fluid stream such as natural gas conveyed in a pipe to inhibit the formation of a hydrate restriction in the pipe. The hydrate inhibitors used for practicing the method comprise substantially water soluble polymers having N-vinyl amide or N-allyl amide units. Specific examples of such copolymers include, N-vinyl-N-methylacetamide (VIMA) copolymerized with acryloylpyrrolidine (APYD) or acryloylpiperidine (APID), and more preferably, VIMA copolymerized with N-substituted methacrylamides, such as N-isopropylmethacrylamide (iPMAM) and methacryloylpyrrolidine (MAPYD) to produce inhibitors for practicing the claimed method.

Abstract: The process for slowing the growth and/or agglomeration of hydrates in a fluid comprising water and gases comprises adding gas hydrate growth and/or agglomeration inhibitors comprising an essentially water soluble polymer, characterized by a total number of rotational degrees of freedom per statistical repeat unit RDFTm of over 9, preferably over 10, and a degree of polymerization DP of a statistical repeat unit in the range 18/RDFTm to 200,000, preferably in the range 20/RDFTm to 100,000. The growth and/or agglomeration inhibitor(s) is/are generally incorporated into the fluid to be treated in a concentration of 0.05% to 5% by weight with respect to the amount of water in the medium.

Abstract: The present invention provides a process for continuously producing clathrate hydrate. This process includes comprising the steps of:(a) pressurizing a hydrate-forming gas to an elevated pressure and cooling the hydrate-forming gas below the gas-water-hydrate equilibrium point at the elevated pressure;(b) cooling liquid water below the gas-water-hydrate equilibrium temperature for the elevated pressure;(c) charging hydrate-forming gas at the elevated pressure into a reaction zone which contains a movable surface;(d) atomizing water in the reaction zone in contact with the hydrate-forming gas to form gas hydrates in the reaction;(e) depositing the gas hydrates on the movable surface; and(f) collecting the gas hydrates from the movable surface.

Abstract: This invention is directed toward a method for inhibiting the formation (nucleation, growth and agglomeration) of clathrate hydrates. The method comprises adding into a mixture of hydrate forming substituents and water, an effective amount of a hydrate anti-agglomerate selected from the group consisting of anionic, cationic, non-ionic and zwitterionic hydrate anti-agglomerate. The hydrate anti-agglomerant has a polar head group and a nonpolar tail group said nonpolar tail group not exceeding 11 carbon atoms in the longest carbon chain.

Abstract: The inhibiting or retarding hydrate formation, growth and/or agglomeration in a fluid comprising water and gases, is accomplished by addition of at least one hydrosoluble homopolymer or copolymer derived from at least one nitrogen-containing monomer selected from cationic monomers, for example those containing at least one quaternary ammonium moiety, amphoteric monomers, for example those containing at least one quaternary ammonium moiety and at least one carboxylate or sulphonate moiety, and various neutral monomers, said hydrosoluble homopolymer or copolymer being neutral or anionic, or consisting of a polyampholyte. The homopolymer, copolymer or mixture of polymers optionally mixed with an alcohol is generally incorporated into the fluid to be treated at a concentration of 0.05% to 5% by weight with respect to the quantity of water in the medium.

Abstract: A process for transporting a fluid in a pipe under conditions where hydrates may form. In the process, the pipe fluid contains at least one of a gaseous hydrocarbon or liquid hydrocarbon and water and the water content is less than the liquid hydrocarbon content. The process includes the steps of 1) adding a dispersive additive in a hydrocarbon solution to the fluid to be transported, so as to form an emulsion, 2) transporting the liquid and gaseous hydrocarbons in the presence of water and the hydrates, 3) separating the gas phase, the hydrocarbon liquid in excess and a liquid hydrocarbon phase comprising the hydrates and the dispersing additive, and 4) separating the liquid hydrocarbon phase comprising the hydrates and the dispersing additives.

Abstract: A method for inhibiting the formation of clathrate hydrates in a fluid having hydrate forming constituents is disclosed. More specifically, the method can be used in treating a petroleum fluid stream such as natural gas conveyed in a pipe to inhibit the formation of a hydrate restriction in the pipe. The hydrate inhibitor used for practicing the method is selected from the family of substantially water soluble copolymers formed from N-methyl-N-vinylacetamide (VIMA) and one of three comonomers, vinylpyrrolidone (VP), vinylpiperidone (VPip), or vinylcaprolactam (VCap). VIMA/VCap is the preferred copolymer. These copolymers may be used alone or in combination with each other or other hydrate inhibitors. Preferably, a solvent, such as water, brine, alcohol, or mixtures thereof, is used to produce an inhibitor solution or mixture to facilitate treatment of the petroleum fluid stream.

Abstract: This invention is directed toward a method for inhibiting the formation (nucleation, growth and agglomeration) of clathrate hydrates. The method comprises adding into a mixture comprising hydrate forming substituents and water, an effective amount of a hydrate inhibitor selected from the group consisting of anionic, cationic, non-ionic and zwitterionic hydrate inhibitors. The hydrate inhibitor has a polar head group and a nonpolar tail group not exceeding 12 carbon atoms in the longest carbon chain.

Abstract: A process is described for retarding or inhibiting the growth and/or aggregation of hydrates in production effluents comprising water and a gas under thermodynamic conditions in which hydrates can form, characterized in that a low concentration (0.05% to 5% by weight with respect to the water) of water-soluble copolymer containing hydrophobic groups is incorporated into the effluent.

Abstract: The invention concerns a process for inhibiting or retarding hydrate formation, growth and/or agglomeration in a fluid comprising water and gases, by addition of a hydrosoluble copolymer which does not contain a heterocycle but contains at least one sulphonate group.The copolymer is generally introduced at a concentration of 0.05% to 5% by weight with respect to the quantity of water in the medium.The copolymer can also be mixed with an alcohol (monoalcohol or polyol). In this case, the proportions are generally 0.5% to 20% by weight of alcohol with respect to the water content, for 0.05% to 3% by weight of copolymer with respect to the quantity of water content of the medium.

Abstract: Novel maleimide copolymers have at least two monomeric units, a maleimide unit and a vinyl unit having a pendant group, the pendant group having two to twenty-one carbon atoms, at least one nitrogen atom and at least one oxygen atom. The copolymer has an average molecular weight between about 1,000 and about 6,000,000. Preferred maleimide copolymers include acrylamide/maleimide copolymers, N-vinyl amide/maleimide copolymers, vinyl lactam/maleimide copolymers, alkenyl cyclic imino ether/maleimide copolymers, and acryloylamide/maleimide copolymers. The substantially water soluble maleimide copolymers are useful for inhibiting the formation of clathrate hydrates in a fluid having hydrate-forming constituents by reducing the rate of nucleation, growth, and/or agglomeration of gas hydrate crystals in a petroleum fluid stream, thereby inhibiting the formation of a hydrate blockage in the pipe conveying the petroleum fluid stream.

Abstract: Discussed is a process for preventing clathrate hydrate masses from detrimentally impeding the possible flow of a fluid susceptible to clathrate hydrate formation. The process is particularly useful in the natural gas and petroleum production, transportation and processing industry where gas hydrate formation can cause serious problems. Additives preferably contain one or more five member, six member and/or seven member cyclic chemical groupings. Additives include polymers having lactam rings. Additives can also contain polyelectrolytes that are believed to improve conformance of polymer additives through steric hinderance and/or charge repulsion. Also, polymers having an amide on which a C.sub.1 -C.sub.4 group is attached to the nitrogen and/or the carbonyl carbon of the amide may be used alone, or in combination with ring-containing polymers for enhanced effectiveness.

Abstract: A method for inhibiting the formation of clathrate hydrates in a fluid having hydrate forming constituents is disclosed. More specifically, the method can be used in treating a petroleum fluid stream such as natural gas conveyed in a pipe to inhibit the formation of a hydrate restriction in the pipe. The hydrate inhibitors used for practicing the method are substantially water soluble polymers formed from a N-substituted acrylamide having two nitrogen substituent groups, R.sub.1 and R.sub.2, where R.sub.1 is a hydrocarbon group having from one to ten carbon atoms and zero to four heteroatoms selected from the group consisting of nitrogen, oxygen, sulfur, and combinations thereof, and R.sub.2 is a hydrogen atom or a hydrocarbon group having from one to ten carbon atoms selected from the group consisting of carbon, nitrogen, oxygen, and sulfur; alternatively, R.sub.1 and R.sub.

Abstract: The invention relates to a process for reducing the agglomeration tendency of hydrates within a fluid containing water and gas by adding a nonionic, amphiphilic compound obtained by reacting at least one polyalkenylsuccinic anhydride or acid with a polyethylene glycol monoether. The nonionic, amphiphilic compound is generally introduced in a concentration of 0.1 to 5% by weight, based on the water present.

Abstract: A process for delaying the formation and/or reducing the agglomeration tendency of hydrates in conditions under which a hydrate may be formed, these hydrates being formed from water and gas.The process according to the invention wherein, in particular, an additive comprising at least one amphiphilic compound chosen from the group of esters of polyols and substituted or unsubstituted carboxylic acids is used.Application of the process according to the invention to processes using gases and water, which form hydrates between them, in particular in the petroleum or gas industry.