KEM-06 Risk assessment for UDG and EGS and an inventory of preventive and mitigation measures

Ultra-deep Geothermal Energy (UDG) as a source of heat and electricity are renewable energy resources is promoted as an option by the Ministry of Economic Affairs (MEA) and Energie Beheer Nederland (EBN).
However, the various hazards and risks associated with UDG have not been thoroughly inventoried and no comprehensive guidelines exist in the Netherlands for quantifying them during all project phases. The State Supervision of Mines (SSM: Staatstoezicht op de Mijnen - SodM) foresees that these risks could become major concerns for UDG-projects in the Netherlands. Hence, as the responsible supervisory agency the State Supervision of Mines considers it critical to obtain a good overview of the risks of UDG projects and strategies for risk management and mitigation.

RESEARCH REQUEST FULL TEXT

The project has investigated and ranked potential risks associated to Ultra Deep Geothermal activities, including stimulation measures (EGS). The project executed first a review of the relevant risks and, based on this list, then suggest a suitable framework for addressing them.

MAIN PROJECT REPORT

The individual risk identification presented on the report is a quite comprehensive and a highly useful resource, based on a broad (although not exhaustive) literature review and expert elicitation. The bowtie approach was selected and deployed as the risk framework. The advantage of the bowtie approach is that threats, top events, barriers and consequences can be presented in a well-structured analysis framework that is understandable and accessible to practitioners. The project successfully involved external input from practitioners and scientists active on the domain, during four hazard identification and prioritization session. This part of the report and the risk classification scheme presented, are highly useful and well-executed applications of the bowtie approach to ultra-deep geothermal plays in the Netherlands. The ability to quickly classify projects risks into qualitative risk categories, based on simplified sets of parameters, is valuable for upcoming projects.
In addition to the main project report a quick-scan risk classification scheme for UDG/EGS risks was delivered, including the User Manual and the Microsoft Excel based relational database file for risk classification, which are available upon request.
USER MANUAL QUICKSCAN TOOL
The Excel based analyses tools provided along with the associated User Guide are valuable additional resources that will help practitioners and regulators to analyze project risks in a semi-quantitative sense.

RESEARCH PROJECT EVALUATION

The project results have been positively reviewed by KEM scientific experts, including the following comments. The main report contains little discussion on the suitability of the bow-tie analysis framework for UDG and in-depth discussion of alternatives, such as probabilistic approaches. While bowtie analysis is a well-established and proven tool, especially in oil and gas industry in the Netherlands, a critical review of the strength and weaknesses of the bowtie approach in the context of UDG and in comparison, with existing and published alternatives, would have been valuable in justifying a future choice to be made for risk management for UDG practice. It is also important to note that the approach proposed is not yet anchored in a regulatory framework in the Netherlands. It can be used by regulators and operators for information purposes but needs to be critically reviewed, adopted or extended before being embedded in existing regulations. See also the recent news message of State Supervision of Mines.