The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Feb. 24, 2015
Filed:
Jan. 20, 2010
Franco Federici, Busto Arsizio, IT;
Thierry Bossi, Orino, IT;
Christian Parisi, Milan, IT;
Luigi Merli, Saronno, IT;
Daniele Moro, Samarate, IT;
Pierangelo Pirovano, Comerio, IT;
Giuseppe LI Bassi, Gavirate, IT;
Franco Federici, Busto Arsizio, IT;
Thierry Bossi, Orino, IT;
Christian Parisi, Milan, IT;
Luigi Merli, Saronno, IT;
Daniele Moro, Samarate, IT;
Pierangelo Pirovano, Comerio, IT;
Giuseppe Li Bassi, Gavirate, IT;
Lamberti SpA, Albizzate(VA), IT;
Abstract
A method for reducing filtrate loss of oil based drilling fluids comprising the following steps: a) preparing by emulsion polymerization an aqueous dispersion containing: i) from 20% to 60% by weight of a copolymer comprising from 60% to 90% by weight of styrene and/or vinyltoluene monomers, from 7 to 40% by weight of 2-ethylhexyl acrylate monomers and from 0.01 to 3% of polyfunctional unsaturated monomers; ii) from 40 to 80% by weight of water; iii) from 0.1% to 5% by weight of at least one surfactant; b) providing an oil based drilling fluid containing the aqueous dispersion obtained from step a), or its copolymer in powder form; c) injecting and circulating the drilling fluid in the borehole.