Development of novel and cost-effective drilling technology for Geothermal Systems

Geothermal is the most under-utilized of renewable sources due to high upfront investment costs and long development cycle. A large part (53%) of the installation cost is drilling, especially number of rig rental days. Hence, major cost reductions can be achieved by increasing Rate-of-Penetration (ROP) and reducing the time involved with moving tools in and out of holes with higher bit & hammer lives. To that end, the Geo-Drill project is proposing a novel drilling technology that incorporates dual fluid hammer, low-cost sensors, 3D printed cables, graphene-based coatings, and improved drill string connections. Graphene's ability to tune to a particular form lends itself uniquely as a component in a wide variety of matrices for coating developments with enhanced adhesion and dispersion properties and improved resistance to abrasion, corrosion, erosion, cavitation and impact. Placing a layer of hard-strength materials between drill bit, hammer and graphene coating by diffusion bonding and brazing will make hammer & bit even stronger. Low cost and robust 3D-printed sensors with 3D printed cables along the whole length of the drill pipe will provide real-time high bandwidth data during drilling; e.g. estimation of rock formation hardness, mud flow speed, density, temperature for optimizing drilling parameters. FlowPhys Geo-Drill simulator combined with sensor readings and knowledge-based system will assist in optimizing drilling parameters. The addition of graphene-based coating, bonding and brazing, low cost sensors, printed cables will enhance the drilling performance even further, leading to very high ROP and drill bit and hammer life. Thereby, the Geo-Drill project has the potential to reduce drilling costs by almost 60%.