Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Surfactant oil recovery method for use in high temperature formations containing water having high salinity and hardness

Patent ·
OSTI ID:6571128
Disclosed is a surfactant fluid employing two or more surfactants, one anionic and one or more nonionic surfactant containing two or more polyethoxy chains such as dipolyethoxylated alkylcatechols or dipolyethoxylated primary alkylamines and a process using the fluid for recovering oil from formations which also contain water having high salinities, e.g., salinities greater than about 40,000 parts per million, and which may include high concentrations of divalent ions such as calcium and/or magnesium, e.g., greater than about 3,000 ppM calcium and magnesium. Nonionic surfactants having two or more polyethoxy chains have substantially higher cloud points than corresponding nonionic surfactants with similar oil soluble groups and the same number of ethoxy groups in a single chain. Superior results are obtained if the nonionic surfactant is chosen to have a cloud point from 20 to 80/sup 0/F above the formation temperature.
Assignee:
Texaco Inc.
Patent Number(s):
US 4120358
OSTI ID:
6571128
Country of Publication:
United States
Language:
English