ABSTRACT
This paper describes a study undertaken to determine the feasibility of hydraulic fracture stimulations in the McArthur River Field, Hemlock formation, Cook Inlet, Alaska. The study reviews the results of Hemlock treatments pumped prior to 1989, the factors influencing the success or failure of the treatments, and steps that could be taken to optimize future treatments. Through 1988, 18 fracture treatments had been attempted to improve productivity from the Hemlock reservoir, a sequence of unconsolidated to poorly consolidated sandstones and conglomerates up to 500 feet thick. The study considered the sensitivity of job success to reservoir properties, the mechanical condition of the well, and fracture stimulation design. To aid in this evaluation, a three-dimensional1 hydraulic fracture simulator (GOHFER) was utilized to match selected previous treatments. In addition, a lab testing program to investigate fracture conductivity under reservoir conditions was undertaken.
The study demonstrated that the majority of previous Hemlock fracture stimulation treatments have been successful when judged by generic economic criteria. A number of critical job design and candidate selection criteria appear to significantly enhance the prospects for a successful hydraulic fracture stimulation. These criteria are discussed in the following. Finally, the results of a successful producing well treatment using information gained from this work are presented.
