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:
Sep. 11, 2007
Filed:
Jun. 30, 2003
Andrew J. Bradbury, Scotland, GB;
Jarrod Massam, Stonehaven, GB;
Christopher A. Sawdon, Par, GB;
M-I LLC, Houston, TX (US);
Abstract
A wellbore fluid having an oleaginous phase and an additive for increasing the density of the wellbore fluid. The additive comprises solid colloidal particles coated with a dispersant during the comminution process of forming the particles. Exemplary starting materials for the colloidal particles include commonly known weighting agents as well as mixture and combinations thereof. The dispersant in one embodiment, is selected from carboxylic acids of molecular weight of at least 150 Daltons. Alternatively, the dispersant coating may be made of compounds including oleic acid, polybasic fatty acids, alkylbenzene sulfonic acids, alkane sulfonic acids, linear alpha-olefin sulfonic acid or the alkaline earth metal salts of any of the above acids, and phospholipids as well as mixtures and combinations of these compounds. In another embodiment the dispersant is a polyacrylate ester having an average molecular weight from about 10,000 Daltons to about 200,000 Daltons.