Flooding method using salt-insensitive polymers for better mobility control
Abstract
Abstract Improved flooding of an oil-bearing subterranean reservoir with an aqueous slug containing a salt-sensitive polymer (example of such a polymer is a partially hydrolyzed, high molecular weight polyacrylamide) and a subsequent drive water which, due to the salt content, tends to degrade the back portion of the aqueous polymer slug, is realized by following the aqueous, saltsensitive polymer slug with a sufficient volume of an aqueous biopolymer slug to ''''insulate'''' the salt-sensitive polymer from the drive water. Drive water having salt concentrations above 1,000 ppm (parts per million) of TDS (total dissolved solids) and especially those waters containing above 50 ppm of polyvalent cations, tends to adversely affect the mobility reducing capabilities of a salt-sensitive polymer. More efficient mobility control is obtained by interjecting the biopolymer slug between the salt-sensitive polymer slug and the drive water. Optionally, a miscible or miscible-like slug can precede the salt-sensitive polymer slug.
Inventors
- 👤 Bruce L Knight
Bibliographic Details
Claims Analysis
Total Claims: 9References Cited (Backward Citations)
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