Abstract: A method of treating a geologic formation including injecting into a wellbore a high viscosity composition which comprises a base fluid wherein the base fluid has an initial viscosity of 100 cP or greater and which exhibits a decrease in viscosity upon exposure to a viscosity reducing agent, and fibers wherein the fibers exhibit flocking upon a decrease in the viscosity of the base fluid, and injecting into the wellbore a viscosity reducing agent wherein the viscosity reducing agent is injected into the wellbore with or separately from the high viscosity composition is provided.

Abstract: Methods for controlling fluid flow through one or more pathways in one or more rock formations penetrated by a borehole in a subterranean well, comprise injecting into or adjacent to the formation a treatment fluid comprising at least one polysaccharide polymer; at least one crosslinker; and fibers, or a mixture of fibers and particles. The fluids are pumped into the well through a tubular body that comprises at least one flow restriction. Shearing of the treatment fluid as it passes through the flow restriction causes the viscosity to decrease, allowing the fibers to form masses that migrate to formation-rock openings such as pores, cracks, fissures and vugs. As a result, the fibrous masses are useful for curing lost circulation, providing fluid-loss control and as diverting agents.

Abstract: A method of treating a geologic formation including injecting into a wellbore a high viscosity composition which comprises a base fluid wherein the base fluid has an initial viscosity of 100 cP or greater and which exhibits a decrease in viscosity upon exposure to a viscosity reducing agent, and fibers wherein the fibers exhibit flocking upon a decrease in the viscosity of the base fluid, and injecting into the wellbore a viscosity reducing agent wherein the viscosity reducing agent is injected into the wellbore with or separately from the high viscosity composition is provided.

Abstract: Methods for controlling fluid flow through one or more pathways in one or more rock formations penetrated by a borehole in a subterranean well, comprise injecting into or adjacent to the formation a treatment fluid comprising at least one polysaccharide polymer; at least one crosslinker; and fibers, or a mixture of fibers and particles. The fluids are pumped into the well through a tubular body that comprises at least one flow restriction. Shearing of the treatment fluid as it passes through the flow restriction causes the viscosity to decrease, allowing the fibers to form masses that migrate to formation-rock openings such as pores, cracks, fissures and vugs. As a result, the fibrous masses are useful for curing lost circulation, providing fluid-loss control and as diverting agents.

Abstract: A method for treating a subterranean formation penetrated by a wellbore is carried out introducing a treatment fluid into the formation through the wellbore wherein the formation has a formation temperature of at least 70° C. A composition for such treatment is also provided. The composition and treatment fluid for the method is formed from water and an amount of fibers formed from high temperature polymers of at least one of a polyester, polyamide, polyurethane, polyurea polymers, and copolymers of these. Each of said high temperature polymers is characterized by the property of not substantially degrading in water at a pH of from 5 to 9 at temperatures below 80° C. A fiber degrading accelerant that facilitates degrading of the fibers at the formation temperature is also included in the treatment fluid.