Development Wells At Fenton Hill HDR Geothermal Area (Dreesen, Et Al., 1987)
Exploration Activity: Development Wells At Fenton Hill HDR Geothermal Area (Dreesen, Et Al., 1987)
|Exploration Activity Details|
|Location||Fenton Hill HDR Geothermal Area|
|Exploration Technique||Development Wells|
|Activity Date||1979 - 1979|
Construction of a second, deeper Phase II reservoir began in 1979 with the drilling of the EE-2 and EE-3 wells to depths of approximately 3500 m in order to extend the HDR technology to the temperatures and rates of heat production required to support a commercial power plant. Initial attempts to connect the two wells by hydraulic pressure-stimulation in 1982 were unsuccessful. Efforts to produce a viable Phase II reservoir continued with the MHF experiment 2032, conducted in 1983 in jointed granitic host rocks with an average temperature of 235°C. Although some 21,600 m^3 of water were injected into EE-2 at an average flow rate of 100 L/s and downhole pressure of 83 MPa, the fracture pattern produced again failed to connect the two wells. A third attempt to fracture the reservoir in 1984 during MHF experiment 2042, this time from the EE-3 well, produced similar results. These difficulties prompted the redirection of well EE-3 in 1985, which was sidetracked at a depth of 2,900 m and re-drilled through the fracture zone associated with EE-2. This re-drilled well is known as EE-3A, and successfully established hydraulic communication between the two wells.
- Donald S. Dreesen, Mark V. Malzahn, Michael C. Fehler, Zora V. Dash (1987) Identification of MHF Fracture Planes and Flow Paths- a Correlation of Well Log Data with Patterns in Locations of Induced Seismicity