Abstract: Viscoelastic surfactant fluids, and methods of using such fluids and controlling the viscosity thereof. In one embodiment, the methods of the present invention comprise: providing a viscoelastic surfactant fluid that comprises an aqueous-base fluid, and a surfactant; providing a metal ion having at least two oxidation states wherein at least one of the oxidation states interferes with the ability of the surfactant to form a viscosifying micelle, wherein at least a portion of the metal ion is present in an oxidation state that interferes with the ability of the surfactant to form a viscosifying micelle; allowing the metal ion to interact with viscoelastic surfactant fluid so as to decrease the ability of the surfactant to form a viscosifying micelle; and introducing the viscoelastic surfactant fluid into at least a portion of a subterranean formation.

Abstract: Viscoelastic surfactant fluids, and methods of using such fluids and controlling the viscosity thereof. In one embodiment, the present invention provides a viscoelastic surfactant fluid comprising an aqueous-base fluid, a surfactant, and a metal ion having at least two oxidation states wherein at least one of the oxidation states interferes with the ability of the surfactant to form a viscosifying micelle.

Abstract: The present invention relates to improved methods for completing well bores along producing zones and, more particularly, to methods for strengthening near well bore subterranean formations. Some embodiments of the present invention provide a method of strengthening the near well bore region of a subterranean formation comprising the steps of isolating a zone of interest along a well bore; either hydrajetting a slot in the zone of interest or acidizing the zone of interest to create wormholes; filling the slot or wormholes with a consolidation material wherein the viscosity of the consolidation material is sufficient to enable the consolidation material to penetrate a distance into the formation; and, allowing the consolidation material to substantially cure.

Abstract: Methods and compositions for removing gelled and dehydrated drilling fluid and filter cake from the walls of wellbores are provided. The methods basically include contacting the drilling fluid and filter cake with a removal composition comprised of an aqueous sugar solution for a period of time sufficient to cause the disintegration of the drilling fluid and filter cake. The composition, having the disintegrated drilling fluid and filter cake dispersed therein, is then displaced from the wellbore.