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Well acidizing

Patent:

Abstract

The apparatus relates in particular to a well-treating process in which an aqueous acid solution having a pH of < 2 is injected into a subterranean reservoir in a manner such that materials that contain ferric ions are present in the acid and, as the acid reacts within the reservoir and attains a pH exceeding 3, tend to be precipitated as ferric ion-containing solid materials that may plug the pores of the reservoir. Such a precipitation is prevented by dissolving in the acid solution an amount of 5-sulfosalicylic acid which is at least sufficient to sequester significant proportions of ferric ions when the pH of the acid is from 0.5 to 3 but is less than enough to cause a significant salting-out of solid materials, and an amount of citric acid which is at least sufficient to sequester significant proportions of ferric ions when the pH of the acid is from 3 to 6 but is less than enough to precipitate a significant amount of calcium citrate. The amount of the 5-sulfosalicylic acid may be from 0.01 to 0.05 moles/l and the amount of citric acid is from 0.001 to 0.009 moles/l. 11 claims.
Authors:
Publication Date:
Jan 23, 1980
Product Type:
Patent
Report Number:
GB 2025489
Reference Number:
EDB-85-052253
Resource Relation:
Patent Priority Date: Priority date 13 Jul 1978, United States of America (USA)
Subject:
02 PETROLEUM; WELLS; ACIDIZATION; CITRIC ACID; CONTROL; IRON COMPOUNDS; PH VALUE; PRECIPITATION; QUANTITY RATIO; SALICYLIC ACID; WELL STIMULATION; CARBOXYLIC ACIDS; HYDROXY ACIDS; ORGANIC ACIDS; ORGANIC COMPOUNDS; SEPARATION PROCESSES; STIMULATION; TRANSITION ELEMENT COMPOUNDS; 020300* - Petroleum- Drilling & Production
OSTI ID:
6077106
Country of Origin:
United Kingdom
Language:
English
Submitting Site:
HEDB
Size:
Pages: v
Announcement Date:

Patent:

Citation Formats

Street, E H. Well acidizing. United Kingdom: N. p., 1980. Web.
Street, E H. Well acidizing. United Kingdom.
Street, E H. 1980. "Well acidizing." United Kingdom.
@misc{etde_6077106,
title = {Well acidizing}
author = {Street, E H}
abstractNote = {The apparatus relates in particular to a well-treating process in which an aqueous acid solution having a pH of < 2 is injected into a subterranean reservoir in a manner such that materials that contain ferric ions are present in the acid and, as the acid reacts within the reservoir and attains a pH exceeding 3, tend to be precipitated as ferric ion-containing solid materials that may plug the pores of the reservoir. Such a precipitation is prevented by dissolving in the acid solution an amount of 5-sulfosalicylic acid which is at least sufficient to sequester significant proportions of ferric ions when the pH of the acid is from 0.5 to 3 but is less than enough to cause a significant salting-out of solid materials, and an amount of citric acid which is at least sufficient to sequester significant proportions of ferric ions when the pH of the acid is from 3 to 6 but is less than enough to precipitate a significant amount of calcium citrate. The amount of the 5-sulfosalicylic acid may be from 0.01 to 0.05 moles/l and the amount of citric acid is from 0.001 to 0.009 moles/l. 11 claims.}
place = {United Kingdom}
year = {1980}
month = {Jan}
}