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. 12, 1992
Filed:
Mar. 05, 1991
Balram Dhawan, St. Louis, MO (US);
Derek Redmore, St. Louis, MO (US);
John L Przybylinski, St. Louis, MO (US);
Petrolite Corporation, St. Louis, MO (US);
Abstract
A method for inhibiting oilfield scale formation including calcite in a high brine environment comprises introducing an effective amount of a scale inhibiting composition to a high brine environment susceptible to calcite scale formation. The environment has a total dissolved solids content of at least about 150 g/l, and the scale inhibiting composition comprises an aminomethylene posphonate of the formula ##STR1## wherein x is 2 or 3, each Z is independently selected from among H and CH.sub.3, and R.sup.1, R.sup.2, R.sup.3, and R.sup.4 are independently selected from among hydrogen and --CH.sub.2 PO.sub.3 M.sub.2 wherein the M's are independently selected from among the hydrogen and cations associated with Lewis bases, such that at least about 80% of the R.sup.1, R.sup.2, R.sup.3, and R.sup.4 in the composition is --CH.sub.2 PO.sub.3 M.sub.2.