Clean Viscosified Treatment Fluids and Associated Methods

Abstract

Treatment fluids comprising an aqueous base fluid, a viscosifying agent, and a compliant dual-functional additive are provided. The present invention provides methods of using the treatment fluids in subterranean formations. One example of a suitable method includes providing a fracturing fluid comprising an aqueous base fluid, a viscosifying agent, and a compliant dual-functional additive that acts as a fluid loss control agent and a breaker and introducing the fracturing fluid into at least a portion of a subterranean formation at a rate and pressure sufficient to create or enhance at least one or more fractures in the subterranean formation.

Description

BACKGROUND OF THE INVENTION[0001]The present invention relates to fluids useful for subterranean operations, and more particularly, to treatment fluids comprising a compliant dual-functional additive and a viscosifying agent, and methods of use employing such treatment fluids to treat subterranean formations.[0002]Aqueous treatment fluids may be used in a variety of subterranean treatments. Such treatments include, but are not limited to, stimulation operations and completion operations. As used herein, the term “treatment,” or “treating,” refers to any subterranean operation that uses a fluid in conjunction with a desired function and / or for a desired purpose. The term “treatment,” or “treating,” does not imply any particular action by the fluid.[0003]An example of a subterranean treatment using an aqueous treatment fluid is hydraulic fracturing. In a hydraulic fracturing treatment, a viscous fracturing fluid is introduced into the formation at a high enough rate to exert a suffici...

AI Technical Summary

Benefits of technology

[0009]In yet another embodiment, the methods of the present invention comprise: providing a treatment fluid comprising an aqueous base fluid, a viscosifying agent, and a compliant dual-functional additive that comprises a fluid loss control agent and a breaker; introducing the treatment fluid into at least a portion of the subterranean formation; and allowing the dual-functional additive to minimize fluid loss by obstructing at least one pore throat opening in the subterranean formation.

Problems solved by technology

In certain circumstances, a portion of the fracturing fluid may be lost during the fracturing operation, e.g., through undesirable leakoff into natural fractures present in the formation.

Many conventional fluid loss control additives permanently reduce the permeability of a subterranean formation, negatively affect the rheology of the treatment fluid in which they are used, and / or reduce the rate at which the fluid is allowed to penetrate or leak off into desirable locations within the subterranean formation.

Thus, costly and time-consuming operations may be required to reverse the effects of conventional fluid loss control additives on the treatment fluid and / or to restore permeability to those portions of the subterranean formation affected by the fluid loss control additives.

Gels that break prematurely can lead to a premature reduction in the fluid viscosity, resulting in a less than desirable fracture width in the formation causing excessive injection pressures and premature termination of the treatment.

On the other hand, gelled fluids that break too slowly can cause slow recovery of the fracturing fluid from the produced fracture with attendant delay in resuming the production of formation fluids and severely impair anticipated hydrocarbon production.

However, the use of these conventional additives may give rise to other problems.

First, the necessity of both a fluid loss control additive and a separate breaker additive in a treatment fluid may increase the complexity and cost of a treatment fluid and / or a subterranean application using that fluid.

In some instances, the fluid loss control additives and breaker additives used are toxic and thus may harm the environment; this problem may be aggravated because many are poorly degradable or nondegradable within the environment.

Due to environmental regulations, costly procedures often must be followed to dispose of the treatment fluids containing such compounds, ensuring that they do not contact the marine environment and groundwater.

Images