Abstract: A fluid flow model is comprised of one cross-flow style core holder and a multitude of standard style core holders, all connected by a concurrent combination of serial and parallel flow paths. The sum of these flow paths yields a fluid flow model that closely approximates a small radial slice of a conventional reservoir. The fluid flow model has particular applicability to estimate the requisite treatment fluid for use in acidizing as well as water control methods.

Abstract: 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.