Acidizing stimulation method using viscoelastic gelling agent

摘要

A method of acidizing a subterranean formation involves the use of a composition containing a solution of a viscoelastic amidoamine oxide surfactant and an HF-containing acidizing solution. The composition typically contains from about 0.1 to about 8 weight percent of surfactant solution and from about 92 to about 99.9 weight percent of HF-containing acidizing solution. The composition is pumped into the subterranean formation. As the acid reacts, the composition viscosifies and becomes a self-diverting agent created in-situ. When the acid is further spent, the fluid viscosity declines eventually returning to a low viscosity state, allowing for easy cleanup. The process allows for selective acidizing of less permeable zones of the formation and more uniform stimulation of the hydrocarbon bearing formulation.