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AssigneeImperial Chemical Industries PLC
InventorsNeil Grainger, Edward George Scovell, Terence Cox
Estimating the term…
The deposition of asphaltenes and/or petroleum waxes can be inhibited and/or asphaltenes and/or petroleum waxes can be removed from a well, pipe or vessel by contacting the asphaltene and/or petroleum wax or the well pipe or vessel adjacent a location where deposition of asphaltene and/or petroleum wax is expected, with a solvent including at least one compound of the formula (I): R1—(AO)n—OOC—(CH2)m—Ph—(R2)p where R1 is a C1 to C20 hydrocarbyl group; AO is an alkyleneoxy group and may vary along the (poly)alkyleneoxy chain; n is 1 or from 1 to 100; m is 0, 1 or 2; and Ph is a phenyl group, which may be substituted with groups (R2)p where each R2 is independently a C1 to C4 alkyl or alkoxy group; and p is 0, 1 or 2, and subsequently removing the solvent with softened, dissolved or dipersed asphaltenes and/or petroleum waxes from the well, pipe or vessel.
1 A method of removing from, or preventing or inhibiting the deposition in, a well, pipe or vessel, of asphaltenes and/or petroleum waxes which comprises contacting the asphaltene and/or petroleum wax or the well pipe or vessel adjacent a location where deposition of asphaltene and/or petroleum wax is expected, with a solvent including at least one compound of the formula (I):
2 A method as claimed in claim 1 wherein m, n and p are all 0.
3 A method as claimed in either claim 1 or claim 2 wherein R1 is a C3 to C5 branched alkyl group.
4 A method as claimed in any one of claims 1 to 3 wherein the solvent is or includes iso-propyl benzoate.
5 A method as claimed in either claim 1 or claim 2 wherein R1 is a C8 to C20 branched and/or unsaturated alkyl or alkenyl group.
6 A method as claimed in any one of claims 1 to 5 wherein the asphaltene and/or petroleum wax is contacted with the solvent at a superambient temperature.
7 A method as claimed in any one of claims 1 to 6 wherein the solvent includes a dispersant for the asphaltene and/or petroleum wax.
8 A method as claimed in any one of claims 1 to 7 to treat an oil storage tank, vessel, or oil refinery pipework to remove deposits of asphaltenes and/or petroleum waxes, in which a solvent including a compound of the formula (I) as defined above, is introduced into the tank, vessel or pipework at or adjacent the location of a deposit of asphaltene and/or petroleum wax, and subsequently softened dispersed or dissolved asphaltene and/or petroleum wax is removed from the tank, vessel or pipework.
9 A method as claimed in any one of claims 1 to 7 to treat an oil well to treat an oil well to remove a deposit of asphaltenes and/or petroleum waxes, in which a solvent including a compound of the formula (I) as defined above, is introduced into the oil well in or adjacent to a deposit on a surface or in a rock formation and subsequently softened dispersed or dissolved asphaltene and/or petroleum wax is removed from the surface or formation.
10 A method as claimed in any one of claims 1 to 7 to treat an oil well to inhibit or prevent the deposition of asphaltenes and/or petroleum waxes, in which a stream of a solvent including a compound of the formula (I) as defined above, is introduced into the oil well in a location, particularly onto a surface or into a rock formation, where deposition is expected thereby carrying away asphaltenes and/or petroleum waxes before they are deposited on the surface or in the formation.