US 7,381,332 B2
Solid-liquid separation of oil-based muds
Jorge Eduardo Adams Pena, Bogota (Colombia); Henry M. Masias, Hamden, Conn. (US); Sun-Yi Huang, Stamford, Conn. (US); and Raymond S. Farinato, Norwalk, Conn. (US)
Assigned to Kemira Oyj, (Finland)
Filed on Jul. 16, 2004, as Appl. No. 10/892,847.
Application 10/892847 is a continuation in part of application No. 10/674441, filed on Sep. 30, 2003, granted, now 7,338,608.
Prior Publication US 2005/0067194 A1, Mar. 31, 2005
This patent is subject to a terminal disclaimer.
Int. Cl. B01D 11/00 (2006.01); C02F 1/44 (2006.01)
U.S. Cl. 210—639  [175/66; 210/732; 210/733] 17 Claims
 
1. A method of separating a solid phase and a liquid phase in an oil-based mud comprising the steps of:
(i) contacting said oil-based mud with a water-in-oil emulsion comprising a polymer derived from at least one water-soluble monomer, wherein said polymer is not dissolved prior to contact with said oil-based mud, wherein the polymer is prepared by water-in-oil emulsion polymerization, and
wherein the emulsion comprises polymer particles of average discrete phase particle size of less than about 10 microns;
(ii) mixing said water-in-oil emulsion and said oil-based mud;
(iii) separating the solid phase and the liquid phase;
wherein said at least one water-soluble monomer is selected from (alkyl)acrylamide, (allyl)acrylic acid, N-vinylpyrrolidone, N-vinylacetamide, N-vinylformamide, acrylonitrile, fumaric acid, crotonic acid, maleic acid, hydroxyalkyl methacrylates, 2-acrylamido-2-alkylsulfonic acids wherein the alkyl group contains 1 to 6 carbon atoms, styrene sulfonic acids; and salts of any of the foregoing thereof; or monomers having the structure of formulas I, II or III

OG Complex Work Unit Drawing
wherein R1, R2, and R5 are each independently hydrogen or a C1 to C6 alkyl; R3 and R4 are each independently hydrogen, a C1 to C12 alkyl, aryl, arylalkyl or hydroxyethyl; and R2 and R4 or R2 and R3 can combine to form a cyclic ring containing one or more hetero atoms; Z is the conjugated base of an acid, X is oxygen or —NR6 wherein R6 is hydrogen or a C1 to C6 alkyl; and A is a C1 to C12 alkylene; and further comprising adding a surfactant.