The success of producing gas from unconventional resources, such as shales, is often tied to maximum exposure to the reservoir. Usually this is achieved by drilling horizontal wellbores and creating fractures that originate from multiple points along the wellbore. Each fracture "stage" must be isolated from the previous stage so as to create additional unique flow paths for the gas. One mechanism to create the fracture isolation points is to use chemical swelling packers between the liner and the formation. These chemical swelling packers can be swollen using water-based fluids, hydrocarbon-based fluids, or combinations of both.

Certain shale formations, like the Lower Huron and Marcellus, are often drilled with air or foam. One reason for air drilling is that these formations have shown a propensity to incur damage from traditional drilling fluids (both hydrocarbon- and water-based). Because of this, there can be reluctance to use traditional fluid systems to activate chemical swelling packers in these formations.

This paper documents the laboratory investigation and development of a novel activation fluid system that minimizes the potential damage to the reservoir but still permits operations to take advantage of the unique characteristics of the chemical swelling packer. Included is a discussion of the operational issues encountered to "scale up" for the first field trials and the results of the first commercial applications.

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