04673522 is referenced by 54 patents and cites 15 patents.

Acid-soluble and/or hydrolyzable obstructions are removed from conduits by contacting such obstructions with a composition containing urea and sulfuric acid in which the urea/sulfuric acid molar ratio is less than 2. The urea/sulfuric acid compositions may optionally contain other components such as surfactants and/or non-aqueous polar solvents which accentuate the activity of the compositions toward hydrophobic materials. Urea-sulfuric acid compositions which contain water and which have H.sub.2 O/(urea+H.sub.2 SO.sub.4) molar ratios below about 2.5 are particularly useful for removing obstructions by partial or complete hydrolysis.

Title
Methods for removing obstructions from conduits with urea-sulfuric acid compositions
Application Number
318629
Publication Number
4673522
Application Date
November 28, 1984
Publication Date
June 16, 1987
Inventor
Donald C Young
Fullerton
CA, US
Agent
Dean Sandford
Greg Wirzbicki
Michael H Laird
Assignee
Union Oil Company of California
CA, US
IPC
C23G 3/04
C11D 7/32
C11D 7/08
B08B 3/08
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