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:
May. 05, 1987
Filed:
Jun. 26, 1985
Dennis K Clapper, Houston, TX (US);
Alphonse C Perricone, Houston, TX (US);
Darrell P Salisbury, Sugarland, TX (US);
Milchem Incorporated, Houston, TX (US);
Abstract
The present invention relates to a surfactant for use in invert emulsion drilling fluids, the invert emulsion drilling fluid produced therefrom, and a method of drilling, completing and working over a subterranean well utilizing said drilling fluid. The drilling fluid comprises an emulsion formed by producing a diamide having from between about 20 mole percent and about 35 mole percent of a polyamine, and from between about 30 mole percent and about 70 mole percent of a fatty acid having from between about 6 to about 20 carbon atoms therein, the diamide thereafter being further reacted with from between about 15 mole percent and about 35 mole percent of a tricarboxylic acid. The total amine value of said oligamide being from between about 10 to about 30, and the acid value of said oligamide being from between about 26 to about 46. When the surfactant is diluted to about 70 w/w percent concentration with a suitable solvent, the ES.sub.3, as defined herein, of said emulsion drilling fluid will exceed about 400 volts, the ES.sub.5, as defined herein, will be greater than the ES.sub.4, and the ES.sub.5 will be greater than about 1,000 volts. Alternatively, the electrical stability of the emulsion drilling fluid, when using the API Electrical Stability Test, should be at least about 1,000 volts.