Self diverting matrix acid
AssigneeSchlumberger Technology Corporation
InventorsDiankui Fu, Mohan Panga, Slaheddine Kefi, Marieliz Garcia-Lopez de Victoria
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Abstract
A method is described for treating a subterranean formation with a low viscosity fluid system that contains a viscoelastic surfactant at a concentration too low to viscosify the fluid, but that is concentrated in the formation so that the fluid system gels. The fluid optionally contains a formation-dissolving agent. The fluid is used in matrix acidizing, acid fracturing, and diversion.
Claims45
A method of treating a subterranean formation penetrated by a wellbore comprising
- a. injecting into said formation a treatment fluid comprising at least one viscoelastic surfactant selected from the group consisting of cationic viscoelastic surfactants, zwitterionic viscoelastic surfactants, and mixtures thereof, at a concentration insufficient for aggregation of viscoelastic surfactant structures to form a viscoelastic fluid, and
- b. allowing the viscoelastic surfactant system to flow through the formation and concentrate in the formation so that aggregation and viscosification occur,
- wherein said treatment fluid further comprises a formation-dissolving agent, and a corrosion inhibitor.
A method of matrix acidizing a subterranean formation penetrated by a wellbore comprising injecting into said formation a treatment fluid comprising at least one viscoelastic surfactant selected from the group consisting of cationic viscoelastic surfactants, zwitterionic viscoelastic surfactants, and mixtures thereof, at a viscoelastic surfactant concentration insufficient for aggregation of viscoelastic surfactant structures to form a viscoelastic fluid and a corrosion inhibitor, wherein said treatment fluid flows through said formation.
A method of acid fracturing a subterranean formation penetrated by a wellbore comprising injecting into said formation a treatment fluid comprising at least one viscoelastic surfactant selected from the group consisting of cationic viscoelastic surfactants, zwitterionic viscoelastic surfactants, and mixtures thereof, at a viscoelastic surfactant concentration insufficient for aggregation of viscoelastic surfactant structures to form a viscoelastic fluid and a corrosion inhibitor, wherein said treatment fluid flows through said formation.
A method of injecting a treatment fluid into a subterranean formation penetrated by a wellbore wherein said treatment fluid comprises at least one viscoelastic surfactant selected from the group consisting of cationic viscoelastic surfactants, zwitterionic viscoelastic surfactants, and mixtures thereof, at a viscoelastic surfactant concentration insufficient for aggregation of viscoelastic surfactant structures to form a viscoelastic fluid, and a corrosion inhibitor, wherein said treatment fluid flows through said formation.
Dependencies are inferred from the claim text.