Viscoelastic surfactants in mixed brines
AssigneeM-I L.L.C.
InventorShaohua LU
Life of this patent
Estimating the term…
Abstract
A wellbore fluid is provided that includes at least one viscoelastic surfactant, a first brine solution including one or more water soluble monovalent cation salts, and a second brine solution including one or more water soluble divalent cation salts in an amount effective to increase the viscosity of the wellbore fluid. The wellbore fluid may be injected into a wellbore as a gravel packing agent, to enhance the thermal insulation of a production tubing or transfer pipe surrounded by at least one annuli, or to reduce fluid loss.
Claims21
A method for injecting a fluid into a wellbore, comprising:
- injecting a wellbore fluid into the wellbore, the wellbore fluid comprising:
- at least one viscoelastic surfactant;
- a first brine solution including one or more water soluble monovalent cation salts;
- and
- a second brine solution including one or more water soluble divalent cation salts in an amount effective to increase the viscosity of the wellbore fluid.
A method of finding of finding an optimal ratio of divalent brine to monovalent brine in a wellbore fluid including a viscoelastic surfactant, the method comprising:
- providing a mixture of viscoelastic surfactant and a monovalent brine;
- adding a divalent brine in incremental values;
- and
- measuring the rheological properties.
A method of gravel packing a hole in a subterranean formation comprising:
- injecting into the hole a gravel pack composition comprising gravel and a carrier fluid,
- the carrier fluid comprising at least one viscoelastic surfactant;
- a first brine solution including one or more water soluble monovalent cation salts;
- and a second brine solution including one or more water soluble divalent cation salts in an amount effective to increase the viscosity of the carrier fluid.
A method for enhancing the thermal insulation of a production tubing or transfer pipe surrounded by at least one annuli comprising:
- (a) adding a wellbore fluid to at least one annuli;
- and
- (b) maintaining the wellbore fluid in contact with the annuli to at least partially immobilize the wellbore fluid,
- wherein the wellbore fluid comprises at least one viscoelastic surfactant;
- a first brine solution including one or more water soluble monovalent cation salts;
- and a second brine solution including one or more water soluble divalent cation salts in an amount effective to increase the viscosity of the wellbore fluid.
A method for reducing fluid loss, the method comprising:
- (a) pumping a selected amount of a fluid loss pill into a formation, the fluid loss pill comprising:
- (i) at least one viscoelastic surfactant;
- (ii) a first brine solution including one or more water soluble monovalent cation salts;
- and
- (iii) a second brine solution including one or more water soluble divalent cation salts in an amount effective to increase the viscosity of the fluid loss pill.
Dependencies are inferred from the claim text.