Coated Pipes for Conveying Oil
AssigneeE. I. Du Pont de Nemours and Company
InventorLAURENCE WAINO MCKEEN
Life of this patent
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Abstract
The present invention relates to an oil pipe having a lining imparting substantially reduced adhesion of asphaltenes, paraffin wax, and inorganic scale, so as to reduce plugging of said oil pipe, and impermeability to salt water so as to protect the oil pipe from corrosion.
Claims19
A down-hole oil pipe comprising a rigid pipe and a lining exposed to oil, said lining comprising a primer layer adhered to the interior surface of the pipe, and an overcoat disposed on top of said primer layer, wherein said overcoat comprises multiple layers including a lower layer and an upper layer, wherein said lower layer comprises a plurality of particles which form a mechanical barrier against permeation of water to the pipe and said upper layer has an exterior anti-stick surface exposed to the oil and consists essentially of baked perfluoropolymer, said lining thereby reducing the deposition of asphaltenes, paraffin wax, and inorganic scale as compared to the interior surface of said oil pipe without said lining being present, so as to avoid pluggage of said rigid pipe, wherein said overcoat is applied as a liquid based composition.
A down-hole oil pipe comprising a rigid pipe and a lining exposed to oil, the lining comprising a primer layer adhered to the interior surface of the pipe, and an overcoat disposed on top of the primer layer, wherein the overcoat comprises multiple layers including a lower layer and an upper layer, where the upper layer has an exterior anti-stick surface exposed to the oil and comprises a copolymer of tetrafluoroethylene with at least one perfluoro(alkyl vinyl ether), the alkyl containing from 1 to 8 carbon atoms, the lining thereby reducing the deposition of at least one of asphaltenes, paraffin wax, and inorganic scale as compared to the interior surface of the oil pipe without the lining being present, so as to avoid pluggage of the rigid pipe, wherein the overcoat is applied as a liquid based composition.
Process for forming an anti-stick lining on the interior surface of a metal pipe comprising:
- 1) applying a primer layer to the interior surface of the pipe, the primer layer comprising a fluoropolymer;
- 2) disposing an overcoat on top of the primer layer, wherein the overcoat comprises a liquid perfluoropolymer composition comprising powder particles having an average particle size of 2 to 60 micrometers;
- 3) baking the layers to form the lining;
- and
- 4) exposing the lining to oil wherein the anti-stick surface reduces the deposition in the pipe of at least one of asphaltenes, paraffin wax, or inorganic scale as compared to the interior surface of the pipe without the lining being present, so as to avoid pluggage of the pipe.
Dependencies are inferred from the claim text.