Patent · US Expired

Acid composition and method for acid treating geological formations

US4101426A · kind A · utility

8Cited by
7References
18Claims
0Family size

Assignee

Inventors

Key dates

Filing dateNov 15, 1976
Grant dateJul 18, 1978
Priority date
Expiry dateNov 15, 1996

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S507/934
  • WIPO fieldBasic materials chemistry
  • WIPO sectorChemistry

Abstract

An acid composition comprising a substantially anhydrous liquid mixture of (1) about 50 to 99 weight percent of polyphosphoric acid having about 5 to 90 weight percent of the total P.sub.2 O.sub.5 present as polymeric P.sub.2 O.sub.5, and (2) about 1 to 25 weight percent of hydrofluoric acid, and in which the H.sub.2 O/P.sub.2 O.sub.5 mole ratio of the overall acid mixture is less than 3.4; and a method for increasing the permeability of siliceous subterranean formations in which the formation is treated with this composition. Also, the composition can optionally contain a catalyst such as a strong mineral acid, a carboxylic acid, an oxidizing agent, or mixtures thereof.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.