Fracturing method using aqueous or acid based fluids
AssigneesCalfrac Well Services Ltd., Chemergy Ltd.
InventorsTravis Allan, Junad Amin, Alan Olson, Ronald Pierce
Life of this patent
Estimating the term…
Abstract
An improved method and fracturing fluid for hydraulic fracturing of a subterranean formation, the fracturing fluid including a surfactant, a water soluble or dispersible anionic organic salt, an acid and a low molecular weight organic solvent.
Claims32
A fluid for fracturing a subterranean formation comprising:
- (i) a surfactant having the general formula
- where R1-R2 are each an aliphatic group of C1-C4, branched or straight chained, saturated or unsaturated, R3 is a group of C12-22, branched, straight or cyclic, saturated or unsaturated;
- (ii) a water soluble or dispersible anionic organic or inorganic salt;
- (iii) an acid;
- and
- (iv) a low molecular weight organic solvent
- wherein the viscosity of the fluid is lowered by raising the pH thereof.
A visco-elastic fluid for fracturing a subterranean formation, the viscosity of the fluid being breakable subsequent to fracturing, said visco-elastic fluid comprising:
- (i) a surfactant having the general formula
- where R1-R2 are each an aliphatic group of C1-C4, branched or straight chained, saturated or unsaturated, R3 is a group of C12-22, branched, straight or cyclic, saturated or unsaturated;
- (ii) a water soluble or dispersible anionic organic or inorganic salt;
- (iii) an acid;
- and
- (iv) a low molecular weight organic solvent.
A method of fracturing a subterranean formation comprising the steps of:
- providing a visco-elastic surfactant based hydraulic fracturing fluid comprising:
- (i) a surfactant having the general formula
- where R1-R2 are each an aliphatic group of C1-C4, branched or straight chained, saturated or unsaturated, R3 is a group of C12-22, branched, straight or cyclic, saturated or unsaturated;
- (ii) a water soluble or dispersible anionic organic or inorganic salt;
- (iii) an acid;
- and
- (iv) a low molecular weight organic solvent,
- pumping said fracturing fluid through a well bore and into a subterranean formation at a sufficient pressure to cause fracturing of said formation;
- and
- lowering the viscosity of said fluid subsequent to said fracturing to facilitate formation clean-up.
A fluid for fracturing a subterranean formation and for use with a breaker system, said fluid comprising:
- (i) a surfactant having the general formula
- where R1-R2 are each an aliphatic group of C1-C4, branched or straight chained, saturated or unsaturated, R3 is a group of C12-22, branched, straight or cyclic, saturated or unsaturated;
- (ii) a water soluble or dispersible anionic organic or inorganic salt;
- and
- (iii) an acid.
Dependencies are inferred from the claim text.