Innovative Downhole Tools for Cause Study and Main tenance in Deep Geothermal Energy

Abstract

The potential of geothermal energy is undoubted. While shallow geothermal energy can be used with minimal risk but with small energy production, deep geothermal energy has still some barriers to overcome. Among high drilling costs, production rates below the expected range make it hard to compete for deep geothermal energy with other energy sources. Additionally, the risks of induced seismic events or uncontrolled water leaks leading to ground lifting obstruct the acceptance and promotion of this technology. With a long history in developing remote-handling tools e.g. for inspection and maintenance of pipes and sewers, the Institute for Applied Computer Science (IAI) started in 2010 with the work on specialized tools for deep geothermal boreholes. The overall target of this project is to provide suitable tools for studying geothermal boreholes, especially with regard to faults and their effects on efficiency and safety of geothermal projects as well as maintenance to recover geothermal boreholes showing respective defects. Since the constraints downhole are challenging, the technical solutions require a high grade of innovation and specialization and are therefore expensive. In order to realize solutions with high quality embodied in affordable tools, a system platform approach is pursued. This approach allows reusing and advancement of basic tool components for a wide range of different applications. When discovering new spaces, it is a human and scientific desire to get visual impressions from the unknown environment. Therefore, following the example of pictures from the Mars, the first functional example of the system platform for downhole tools, is a video inspection system called GeoKam. Besides the obvious wish for a literal insight in deep geothermal boreholes, the video application provides several advantages. Since it is a complex operation to record, process and transfer live-videos from deep geothermal boreholes, the device shows the performance of the system platform regarding the main challenges of downhole operation: high temperatures, high pressures, small spaces and long distance tool handling and data transfer via wirelines. Beyond that, a live downhole video stream is a necessary precondition for maintenance operations as leakage repair.