COMPOSITIONS AND METHODS FOR TREATING SUBTERRANEAN FORMATIONS

摘要

Methods for treating subterranean wells in which the producing formation is a carbonate comprise preparing a treatment fluid comprising either: (a) an aqueous solution of a multivalent-cation reacting polymer; (b) a solution comprising a fatty acid and an ethanolamine; (c) an aqueous acidic solution of one or more compounds whose calcium salts are insoluble; or (d) an aqueous solution comprising urea or alkane derivatives thereof or both and polyvinylpyrrolidone (PVP). The treatment fluid is placed in the well such that the solution contacts the carbonate formation at a pressure lower than the fracturing pressure. The treatment fluid is allowed to react with the carbonate formation, thereby depositing a film onto the formation surface or part of the formation surface. Then an acid solution is placed in the well such that the acid contacts the carbonate formation at a pressure lower than the fracturing pressure.

主权项

1. A treatment fluid system, comprising
(i) a first fluid comprising either:
an aqueous mixture of a multivalent-cation reacting polymer;a mixture of a fatty acid and an ethanolamine;an aqueous acidic mixture of one or more compounds whose calcium salts are insoluble; oran aqueous solution comprising polyvinylpyrrolidone (PVP) and urea or alkane derivatives thereof or both; and (ii) a second fluid comprising an acid.