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:
Dec. 15, 1992
Filed:
May. 29, 1991
David R Underdown, Plano, TX (US);
Atlantic Richfield Company, Los Angeles, CA (US);
Abstract
While many materials have been used to inhibit scale formation previously, none have been fully satisfactory to prevent scale formation and precipitation of totally dissolved solids (TDS) in fluids used in well drilling, completion and workovers when the fluids contain divalent metal cations and when the formation contains carbon dioxide. Since many wells are completed into such formations, a continuing search has been directed to an improved method for preventing the formation of such scale. According to the present invention, metal carbonate scale formation and TDS precipitation in a well penetrating a subterranean formation wherein a fluid containing calcium, magnesium, barium or zinc is used in the presence of carbon dioxide is prevented by maintaining the fluid at a pH from about 2 to about 9 and adding from about 1 to about 5000 parts per million of a phosphonomethylated oxyalkyleneamine material having a molecular weight from about 150 to about 3000 to the fluid.