Completion technology has evolved significantly since the first San Juan Basin coalbed methane wells drilled in the 1950's. Initially wells were completed openhole, however, hole stability was a major problem in addition to the inability to isolate different coal seams. A cased hole type completion was later adopted utilizing perforations and hydraulic fracture stimulations. Recently openhole type completions are again popular with some San Juan Basin operators, in which a large cavity is created in the coal seams of the openhole interval. The openhole section is then lined with pre-perforated uncemented casing. Both cased hole with fracture stimulations and openhole cavity completion techniques are currently being used in the San Juan Basin at the Northeast Blanco Unit operated by Blackwood and Nichols Company, Ltd. This provides a unique opportunity to compare the techniques to determine which technique is best.

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