METHOD OF LOWERING THE WAX APPEARANCE TEMPERATURE OF CRUDE OIL CONTAINING WAX DEPOSITS AND METHOD OF REDUCING THE DEPOSITION OF WAX FROM CRUDE OIL

摘要

1. A method of lowering the wax appearance temperature of a crude oil containing wax which comprises adding thereto at least one N-substituted polyalkyleneimine which has at least one organic substituent that is an hydroxy-substituted alkyl group of 12-carbon atoms which is bonded to a chain or terminal N atom of the polyalkyleneimine either directly, or via an ether oxygen or an SO2 intermediate group. 2. A method of reducing the deposition of wax from a crude oil containing wax which comprises adding thereto at least one N-substituted polyalkyleneimine which has at least one organic substituent that is an hydroxy-substituted alkyl group of 12-24 carbon atoms which is bonded to a chain or terminal N atom of the polyalkyleneimine either directly, or via an ether oxygen or SO2 intermediate group. 3. A method as claimed in claims 1 and 2 in which the crude oil contains 0.5% to 50% by weight of wax. 4. A method as claimed in claims 1 to 3 in which the crude oil contains dissolved gas, water or water droplets. 5. A method as claimed in claims 1 to 4 in which the N-substituted polyalkyleneimine is added to the crude oil in an amount of 400-2000 ppm. 6. A method as claimed in claims 1 to 5 wherein the N-substituted polyalkyleneimine has a polyalkylene imine backbone of the molecular weight of 600 to 1,000,000.