| abstract |
The invention relates to a method for producing a water-soluble copolymer which is added during the stimulation of natural gas and oil drilled holes by means of pressure control with a sulfuric solution to the acids used as friction inhibitors. THE INVENTION COPOLYMERISATE INCLUDES AT LEAST 5% BY WEIGHT OF UNITS WHICH HAVE A FORMYLAMINOGRUPPE OF FORMULA A), WHICH IS HIGH 1 HYDROGEN, METHYL OR HYDROXYLMETHYL, AND AT LEAST 10% BY WEIGHT OF UNITS WHICH ARE AN AMINOCARBONYL GROUP OF THE FORMULA B). THE COPOLYMERISATE IS SITUATED IN A STATIC DISTRIBUTION OF 5 TO 50% BY WEIGHT OF UNITS OF FORMULA I, 10 TO 95% BY WEIGHT OF UNITS OF FORMULA II AND 0 TO 85% BY WEIGHT OF UNITS OF FORMULA III TOGETHER. R HIGH 1 = HYDROGEN, METHYL OR HYDROXYMETHYL; R HIGH 2 = HYDROGEN OR METHYL; X = CYAN, CARBOXYL U.A. FORMULAS A), B), I, II, AND III. DD # AP |