Ralf Oppermann of Optimal Resource Solutions presented this discussion on fault extraction from seismic data on 18 April as a part of the AGA webinar series.
Members can access a copy of the presentation via the link below.
Geothermal energy has the potential to play a very important role in the sustainable global energy mix. There are, however, several technical and economic challenges that need to be overcome to de-risk geothermal development and production and to help accelerate commercial uptake (Drumm et al. 2021).
Two of the key technical challenges for most types of deeper geothermal development are ensuring that sufficient and continuous flow of fluid is encountered (flow assurance) and that geothermal operations don’t trigger earthquakes (induced seismicity risk mitigation).
Both of these key challenges can actually be addressed with the latest game-changing advancements in the reliable recognition of smaller-scale fault networks in seismic data, which will be presented in this talk.
Hi-Res Automated Fault Extraction (HR-AFE) allows to very reliably visualize fault networks in 2D or 3D seismic data and directly relate these to drilling and production issues, allowing to create opportunities to significantly reduce drilling and stimulation/fracking costs and also increase production from subsurface assets (oil & gas, minerals, water, heat; Oppermann 2012a+b).
Fluid flow rates and reservoir temperatures determine the power output of a geothermal resource. Understanding the matrix and/or fracture permeability is key to modelling the reservoir response and production sustainability (Drumm et al. 2021).
In both Hot Dry Rock (HDR) and Engineered Geothermal Systems (EGS), where fluids are circulated through a stimulated fracture system, knowledge about pre-existing fault and fracture networks is key for the full understanding and meaningful modelling of flow and it is also key for project planning and placement/targeting of injector and producer wells.
High-res Fault Extraction should be the standard addition to HDR and EGS workflows as it very reliably delineates interconnected fault networks in the subsurface and allows to target these for flow assurance (injector-producer pathways). It also allows to avoid faults if they could cause drilling problems or earthquakes (induced seismicity risk mitigation).
Induced seismicity has been a key risk that has been established following earthquake links to previous geothermal developments. A magnitude 3.4 earthquake in Switzerland in 2006 damaged buildings and led to the geothermal plant’s closure, and a magnitude 5.5 earthquake in South Korea in 2017 injured 90 people and caused $52 million in damages.
The Talk will show examples of the successful application of HR-AFE to Oil & Gas, Mining and Geothermal assets around the globe. Case Studies will include conventional & unconventional Oil & Gas reservoirs, a Geothermal project in Western Australia (Ballesteros et al. 2012), and Basement/hard rock studies where faults were delineated at high resolution in e.g. Granites (Yemen) and magmatic and metamorphic rocks (Vietnam, Finland).
High-resolution fault visualization and evaluation can reduce the uncertainty in the success of Geothermal projects as it is instrumental in addressing the typical challenges for deep geothermal developments. It is proposed as a best-practise technique for Geothermal Companies to implement as it delivers
- reduced drilling & stimulation/fracking risks and costs
- increased reservoir performance/flow
- reduced induced seismicity risks
References
Ballesteros, M., Oppermann, R., Meyer, G., McDairimid, J. & Larking, A., 2012. Targeting fracture permeability for geothermal developments in the North Perth Basin. Proceedings of the 2012 Australian Geothermal Energy Conference, 14-16 November 2012, Sydney/Australia.
Drumm, E., Bolton, R., Hardman, J. & MacInnes, E., 2021. Technical challenges in geothermal development and production. 2nd Geoscience and Engineering in Energy Transition Conference, GET 2021. EAGE.
Oppermann, R., 2012a. Finding sweet spots through Seismic Fracture Extraction – Unconventional Case Studies from around the world. Asia Pacific Oil & Gas Conference & Exhibition (APOGCE), 22-24 October 2012, SPE 158786.
Oppermann, R., 2012b. New method for seismic identification of fluid conduits or barriers challenges several industry paradigms. AAPG/SPE/SEG Hedberg Research Conference, Fundamental Controls on Flow in Carbonates, 8-13 July 2012, France.
Biography
Ralf Oppermann is a Geoscientist and Technical Advisor with 34 years of experience, obtained working for Shell and Chevron and multiple other Oil & Gas, Mining and Geothermal companies.
In 2008, Ralf founded OPPtimal Resource Solutions (‘OPPtimal’) as a technology service company, to provide new and leading-edge resource characterization solutions to companies active in Oil & Gas, Shale Gas, Coal Seam Gas, Mining, Geothermal, Groundwater, CO2 Sequestration and Underground Storage. OPPtimal has developed a Game-Changing and AAPG-awarded technology method to very reliably identify smaller-scale faults from 2D or 3D seismic data and directly relate these to drilling and production issues. The method not only allows to identify and address drilling and flow issues in existing wells but also allows to plan future wells to directly target (or avoid) flow-enhancing fault zones/sweet spots and realise significant drilling and completion/fracking cost reductions and increased production from subsurface assets (oil & gas, minerals, water, heat). For this work, Ralf received the "Innovator in Geosciences Technology" Award from the Innovation and Emerging Science/Technology Group of AAPG.