Development of a Reservoir Stimulation Model at Pilgrim Hot Springs, Alaska using TOUGH2

Abstract

Development of a Reservoir Stimulation Model at Pilgrim Hot Springs, Alaska using TOUGH2 Arvind Chittambakkam1, Ronald P. Daanen2,*, Christian Haselwimmer1, Anupma Prakash1, Markus Mager3 and Gwen Holdmann3 2Water Resources and Environmental Research Center, Institute of Northern Engineering, University of Alaska Fairbanks (UAF); 1Geophysical Institute, UAF; 3Alaska Center for Energy and Power, UAF *Corresponding author: rdaanen@alaska.edu Abstract: This paper discusses developing a reservoir stimulation model using TOUGH2 at Pilgrim Hot Springs, Alaska. Preliminary work suggests a conceptual model for Pilgrim Hot Springs, Alaska to be steady-state model. This model uses the EOS3 (water and air) module of the TOUGH simulator, and implements the same thermophysical properties model as described in Pruess, (1987). The current work involves developing scenarios to predict the location of the heat source and its distance from the surface geothermal anomaly based on the expected temperature profiles generated in the shallow aquifer and springs. The current model assumes that the heat source is located at a considerable distance with a conduit of high hydraulic conductivity located across the reservoir feeding the shallow aquifer. The temperature logs from the wells and geoprobes across the reservoir are used as reference temperatures to be generated across the shallow aquifer. Geological and geophysical data are utilized to be incorporated into the model. The boundary conditions utilized in this work consists of geothermal area bounded by permafrost which has a significant influence in the simulation results. Current work also involves predicting the size and strength of the heat source for the geothermal system. This work involves developing a high resolution model focusing on the shallow aquifer to better represent the temperature profiles across the shallow reservoir in order to explore the heat extraction in the sedimentary basin.