Method of treating flow conduits and vessels with foamed composition
The annular surface between the tubing and casing of an oil or gas well as well as flow conduits and vessels may be contacted with a foamed treatment composition containing a gas, a foaming agent and a treatment agent. The treatment agent may be an inhibitor or removal agent for scales, corrosion, salts, paraffins or asphaltenes. The foam, upon destabilization, renders a thin film of concentrated treatment agent on the external surfaces of the tubing, inside the casing and in the perforations of the oil or gas well or on the flow conduits or vessels.
1. A method of removing unwanted deposits from a surface of a flow conduit or vessel which comprises introducing into the flow conduit or vessel a foamed treatment composition comprising a foaming agent and a treatment agent wherein the amount of foaming agent in the foamed treatment composition is an amount sufficient to provide a foam quality to the foamed treatment composition which is greater than or equal to 90% and further wherein, upon destabilization of the foamed treatment composition, a thin film concentrate of the treatment agent is coated over at least a portion of the surface.
2. The method of claim 1 , wherein the treatment agent is an inhibitor or removal agent for unwanted deposits selected from the group consisting of scales, rust, salts, paraffins and asphaltenes.
3. The method of claim 1 , wherein the foaming agent has a half-life less than or equal to 1 hour.
4. The method of claim 1 , wherein the foaming agent is anionic or amphoteric.
5. The method of claim 4 , wherein the foaming agent is an anionic foaming agent selected from the group consisting of alkyl ether sulfates, alkoxylated ether sulfates, phosphate esters, alkyl ether phosphates, alkoxylated alcohol phosphate esters, alkyl sulfates and alpha olefin sulfonates.
6. The method of claim 1 , wherein the treatment agent is a removal agent for scales and is selected from the group consisting of mineral acids and weak organic acids.
7. The method of claim 6 , wherein the treatment agent is selected from the group consisting of HCl, acetic acid and formic acid.
8. The method of claim 1 , wherein the treatment agent is a removal agent scales and is selected from the group consisting of alkyl-substituted phosphonium compounds and alkyl-substituted phosphines.
9. The method of claim 8 , wherein the treatment agent is an alkyl-substituted phosphonium compound of formula (I):
or an alkyl-substituted phosphine of formula (II):
wherein X is an anion; n is the valency of X represented by m; each A are the same or different and are selected from the group consisting of —OH, —OR 1 , —SO 3 R 1 , —PO 3 (R 1 ) 2 , —COOH, —COOR 1 , SO 3 H, —PO 3 H 2 , —CH 2 COOH, substituted alkyl, aryl or substituted amino groups; each R and each R 1 is independently selected form the group consisting of hydrogen, a C 1 to C 20 alkyl, aryl, substituted alkyl or aryl, carboxy or carboxy ester.
10. The method of claim 9 , wherein the alkyl-substituted phosphonium compound is selected from the group consisting of tetrakis(hydroxymethyl)phosphonium sulfate (THPS), tetrakis(hydroxymethyl)phosphonium chloride, tetrakis (hydroxymethyl)phosphonium bromide, tetrakis(hydroxymethyl)phosphonium acetate and tetrakis(hydroxymethyl)phosphonium phosphate.
11. The method of claim 1 , wherein the surface is metallic or non-metallic.
12. The method of claim 1 , wherein the flow conduit or vessel is used in the production of oil or gas, refineries or a fluid processing facility.
13. A method of removing unwanted deposits from a flow conduit or vessel which comprises introducing into the conduit or vessel a treatment composition comprising a foaming agent and a treatment agent wherein the treatment agent is present in the treatment composition in an amount sufficient such that a thin film of concentrate of the treatment agent coats at least a portion of the surface of the flow conduit or vessel upon breaking of the treatment composition.
14. The method of claim 13 , wherein the treatment agent is an inhibitor or removal agent for unwanted deposits selected from the group consisting of scales, rust, salts, paraffins and asphaltenes.
15. The method of claim 14 , wherein the treatment agent is at least one of the following:
(a) scale treatment agents selected from the group consisting of phosphates, phosphate esters, phosphoric acid, phosphonates, phosphonic acid, phosphonate/phosphonic acids, polyacrylamides, salts of acrylamido-methyl propane sulfonate/acrylic acid copolymers (AMPS/AA), phosphinated maleic copolymers (PHOS/MA) and salts of a polymaleic acid/acrylic acid/acrylamido-methyl propane sulfonate terpolymer (PMA/AMPS), hydrochloric acid, acetic acid, formic acid, sodium hydroxide, EDTA chelants, glucoheptanate and urea;
(b) corrosion treatment agents selected from the group consisting of fatty imidazolines, alkyl pyridines, alkyl pyridine quaternaries, fatty amine quaternaries and phosphate salts of fatty imidazolines;
(c) paraffin treatment agents selected from the group consisting of ethylene/vinyl acetate copolymers, acrylates and olefin/maleic esters; and
(d) asphaltene treatment agents selected from the group consisting of fatty ester homopolymers and copolymers and sorbitan monooleate.
16. The method of claim 14 , wherein the treatment agent is a removal agent for scales and is selected from the group consisting of mineral acids and weak organic acids.
17. The method of claim 16 , wherein the treatment agent is selected from the group consisting of HCl, acetic acid and formic acid.
18. The method of claim 14 , wherein the treatment agent is a scale removal agent selected from the group consisting of alkyl-substituted phosphonium compounds and alkyl-substituted phosphines.
19. The method of claim 18 , wherein the treatment agent is an alkyl-substituted phosphonium compound of formula (I):
or an alkyl-substituted phosphine of formula (II):
wherein X is an anion; n is the valency of X represented by m; each A are the same or different and are selected from the group consisting of —OH, —OR 1 , —SO 3 R 1 , —PO 3 (R 1 ) 2 , —COOH, —COOR 1 , SO 3 H, —PO 3 H 2 , —CH 2 COOH, substituted alkyl, aryl or substituted amino groups; each R and each R 1 is independently selected form the group consisting of hydrogen, a C 1 to C 20 alkyl, aryl, substituted alkyl or aryl, carboxy or carboxy ester.
20. The method of claim 19 , wherein the alkyl-substituted phosphonium compound is selected from the group consisting of tetrakis(hydroxymethyl)phosphonium sulfate (THPS), tetrakis(hydroxymethyl)phosphonium chloride, tetrakis (hydroxymethyl)phosphonium bromide, tetrakis(hydroxymethyl)phosphonium acetate and tetrakis(hydroxymethyl)phosphonium phosphate.