| Title | An Analysis of the Hydrologic Effects of Proposed Test Drilling in The Winema National Forest near Crater Lake, Oregon |
|---|---|
| Authors | Sammel, Edward A.; Benson, Sally |
| Year | 1987 |
| Conference | Geothermal Resources Council Transactions |
| Keywords | Exploration; Geochemistry; Oregon; Crater Lake; Geology; Hydrology; Caldera; Heat Flow; Magma; Magma Chamber; Ground Water Flow |
| Abstract | This paper describes the results of a preliminary study of the hydrologic regime underlying the Crater Lake Caldera, Oregon. The study was performed to provide a basis for evaluating the potential for polluting Crater Lake by drilling exploratory boreholes on the flanks of the mountain. A simple conceptual model of the hydrologic regime was developed by synthesizing the data from the region surrounding the Caldera. Based on the conceptual model, a series of numerical simulations aimed at establishing the basic groundwater flow patterns under and surrounding the lake were performed. In addition to the numerical simulations, we used simple volumetric technique for estimating the distance that drilling mud would migrate way from the borehole if drilling proceeded without drilling fluid returns. Based on our calculations that show the regional flow of groundwater will oppose the flow of drilling mud toward the lake, and based on our volumetric estmate of drilling mud migration, our study concludes that drilling without returns will not pollute Crater Lake, nor will it affect the hydrologic regime in the immediate vicinity of the Crater Lake Caldera. |