Method of manufacture and use of large hydrophobe ether sulfate surfactants in enhanced oil recovery (EOR) applications
AssigneeBoard of Regents, The University of Texas System
InventorsUpali P. Weerasooriya, Gary A. Pope, Quoc P. Nguyen
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Abstract
The present invention describes the method of making anionic ether sulfate surfactants by alkoxylation of a GA using PO and/or EO followed by a sulfation reaction. The GA of the present invention is made by a facile and inexpensive method that involves high temperature base catalyzed dimerization of a linear alcohol. The ether sulfate surfactants of the present invention find uses in EOR applications where it is used for solubilization and mobilization of oil and for environmental cleanup.
Claims51
A method Comprising the steps of:
- (a) dimerizing a linear alcohol in the presence of a base to form a Guerbet alcohol, wherein yields a blend comprising between 85 wt % and 95 wt % of the Guerbet alcohol and between 5 wt % and 15 wt % of the unreacted linear alcohol;
- (b) converting the blend to a surfactant;
- (c) forming a surfactant formulation comprising the surfactant, an alkalinity generating agent, and a solvent, wherein the surfactant and the alkalinity generating agent are dissolved in the solvent.
A composition comprising:
- (i) an anionic ether sulfate surfactant having a formula of:
- CnH2n+1O—POx-EOy—SO3−
- wherein
- (a) PO is propylene oxide,
- (b) EO is ethylene oxide,
- (c) n is an integer between 12 and 44, inclusive,
- (d) x is an integer between 0 and 50, inclusive, and
- (e) y is an integer between 0 and 100, inclusive;
- (ii) an alkalinity generating agent;
- and
- (iii) a solvent, wherein the anionic ether sulfate surfactant and the alkalinity generating agent are dissolved in the solvent.
A method of using an anionic ether sulfate surfactant formulation for enhanced oil recovery from a hydrocarbon bearing formation comprising the steps of:
- (a) injecting an anionic ether sulfate surfactant composition into the hydrocarbon hearing formation at a temperature between 25° C. to 120° C., wherein,
- (i) the anionic ether sulfate composition comprises an anionic ether sulfate having a chemical formula
- CnH2n+1O—POx-EOy—SO3−,
- wherein (A) PO is propylene oxide, (B) EO is ethylene oxide, (C) n is an integer between 12 and 44, inclusive, (D) x is an integer between 0 and 50, inclusive, and (E) y is an integer between 0 and 100, inclusive, and
- (ii) the anionic ether sulfate composition is injected either alone or as an alkaline-surfactant-polymer formulation (ASP);
- and
- (b) injecting a polymer push solution to recover oil.
Dependencies are inferred from the claim text.