Automated Fracture Point Calculation Procedure
I. Ravimo, K. Tiensuu and E. Heikkinen
Event name: 25th European Meeting of Environmental and Engineering Geophysics
Session: High-Resolution Seismics II
Publication date: 11 September 2019
Info: Extended abstract, PDF ( 756.09Kb )
Price: € 20
Posiva Oy is responsible for preparation of final disposal of spent nuclear fuel in Olkiluoto and has done extensive research to ensure the over-all safety of the final disposal. Final disposal is scheduled to start in 2020’s. Extensive geophysical survey programs have been executed in both deep boreholes and pilot holes located in the vicinity of planned disposal site. Scope of the automated fracture point calculation procedure was to automatically detect the most significant fractures from geophysical data based on known fracture locations and geophysical anomalies. This approach sets high demands for the processing and depth correction accuracy of the data. Automation was implemented using R programming language. Calculation procedure is applied to one hole at the time and processing constants were determined using existing data from pilot holes. Fracture point calculation procedure returns scaled parameter specific points and scaled total points for each fracture. Fractures are then classified based on their total points in order to determine their relevancy. The most relevant ones get the highest total points but in some cases it can also be beneficial to concentrate only on certain methods. Results are used in Rock Suitability Classification process together with geological and hydrogeological data.