1887
Volume 1, Issue 1
  • E-ISSN:
PDF

Abstract

Utilizing existing temperature and structural geology information around Granite Springs Valley, Nevada, we build 3D stochastic temperature models with the aims of evaluating the 3D uncertainty of temperature and choosing between candidate exploration well locations. The data used to support the modelling are measured temperatures and structural proxies from 3D geologic modelling (distance to fault, distance to fault intersections and terminations, Coulomb stress change and dilation tendency), the latter considered ‘secondary’ data. Two stochastic geostatistical techniques are explored for incorporating the structural proxies: cosimulation and local varying mean.

With both the cosimulation and local varying mean methods, many equally-likely temperature models (i.e. realizations) are produced, from which temperature probability profiles are calculated at candidate well locations. To aid in choosing between the candidate locations, two quantities summarize the temperature probabilities: and entropy. quantifies the likelihood for economic temperatures at each candidate location, whereas entropy identifies where new information has the most potential to reduce uncertainty.

In general, the cosimulation realizations have smoother spatial structure, and extrapolate high temperatures at candidate locations that are located along the direction of the longest spatial correlation, which are down dip from existing temperature logs. The smooth realizations result in tight temperature probability profiles that are easier to interpret, but they have unrealistic temperature reversals in some locations because of the dipping ellipsoid shape created and that the cosimulation technique does not enforce a conductive geothermal gradient as a baseline (i.e. linearly increasing temperature with depth). The local varying mean results produce realizations with more realistic geothermal gradients, with temperatures increasing downward since a depth-temperature relationship is included. However, because they have much noisier spatial nature compared to cosimulation, it is harder to interpret the temperature probability profiles. The different local varying mean results allow the geologist to determine which proxy (e.g. dilation v. distance to fault termination) should be used given the specific geothermal system. In general, from local varying mean results identify locations that are close to high values for the structural proxies: areas with higher probabilities for higher temperatures. The entropy results identify where uncertainty is greatest and therefore new drilling information could be most useful. Though these techniques provide useful information, even when applied to areas of sparse data, our comparison of these two techniques demonstrates the need for new geothermal geostatistics techniques that combine the advantages of these two methods and that are tailored to the spatial uncertainty issues inherent in geothermal exploration.

[open-access]

Loading

Article metrics loading...

/content/journals/10.1144/geoenergy2023-010
2023-12-06
2025-06-20
Loading full text...

Full text loading...

/deliver/fulltext/geoenergy/1/1/geoenergy2023-010.html?itemId=/content/journals/10.1144/geoenergy2023-010&mimeType=html&fmt=ahah

References

  1. Ayling, B. and Hinz, N.2020. Developing a conceptual model and power capacity estimates for a low-temperature geothermal prospect with two chemically and thermally distinct reservoir compartments, Hawthorne, Nevada, USA. Geothermics, 87, https://doi.org/10.1016/j.geothermics.2020.101870
    [Google Scholar]
  2. Ayling, B., Kirby, S., Hardwick, C., Kleeber, E. and Trainor-Guitton, W.2022. INGENIOUS Phase 1 (budget period 1) progress report.
  3. Boyd, D.L., Walton, G. and Trainor-Guitton, W.2020. Geostatistical estimation of Ground Class prior to and during excavation for the Caldecott Tunnel Fourth Bore project. Tunnelling and Underground Space Technology, 100, 103391, https://doi.org/10.1016/j.tust.2020.103391
    [Google Scholar]
  4. Chilès, J.-P. and Delfiner, P.2012. Geostatistics: Modeling Spatial Uncertainty. 2nd edn, Wiley.
    [Google Scholar]
  5. Craig, J.W., Faulds, J.E. et al.2021. Discovery and analysis of a blind geothermal system in Southeastern Gabbs valley, Western Nevada, USA. Geothermics, 97, https://doi.org/10.1016/j.geothermics.2021.102177
    [Google Scholar]
  6. Cumming, W.2016a. Resource capacity estimation using lognormal power density from producing fields and area from resource conceptual models; advantages, pitfalls and remedies. In:Proceedings of the 41st Workshop on Geothermal Reservoir Engineering Stanford University, 22–24 February, Stanford, California.
    [Google Scholar]
  7. Cumming, W.2016b. Resource Conceptual Models of Volcano-Hosted Geothermal Reservoirs for Exploration Well Targeting and Resource Capacity Assessment: Construction, Pitfalls and Challenges. Geothermal Research Council Transactions, 40, 623–638.
    [Google Scholar]
  8. De Lathauwer, L., De Moor, B. and Vandewalle, J.2000. A multi- linear singular value decomposition. SIAM Journal on Matrix Analysis and Applications, 21, 1253–1278, https://doi.org/10.1137/S0895479896305696
    [Google Scholar]
  9. Deutsch, C.V. and Journel, A.G.1998. GSLIB: Geostatistical Software Library and User's Guide. Oxford University Press, New York.
    [Google Scholar]
  10. Faulds, J.E., Coolbaugh, M.F., Benoit, D., Oppliger, G., Perkins, M., Moeck, I. and Drakos, P.2010. Structural controls of geothermal activity in the northern Hot Springs Mountains, western Nevada: the tale of three geothermal systems (Brady's, Desert Peak, and Desert Queen). Geothermal Resources Council Transactions, 34, 675–683, https://publications.mygeoenergynow.org/grc/1028722.pdf
    [Google Scholar]
  11. Faulds, J.E., Hinz, N.H. et al.2015a. Discovering Blind Geothermal Systems in the Great Basin Region: An Integrated Geologic and Geophysical Approach for Establishing Geothermal Play Fairways.
  12. Faulds, J.E., Hinz, N.H. et al.2015b. Integrated geologic and geophysical approach for establishing geothermal play fairways and discovering blind geothermal systems in the Great Basin Region, Western USA: a progress report. Geothermal Research Council Transactions, 39, 691–700.
    [Google Scholar]
  13. Faulds, J.E., Hinz, N.H. et al.2017. Progress report on the Nevada play fairway project: integrated geological, geochemical, and geophysical analyses of possible new geothermal systems in the Great Basin Region. In:Proceedings, 42nd Workshop on Geothermal Reservoir Engineering, Stanford University,Stanford, California.
    [Google Scholar]
  14. Faulds, J., Hinz, N. et al.2019. Vectoring into potential blind geothermal systems in the granite Springs Valley Area, Western Nevada: application of the play fairway analysis at multiple scales. In:Proceedings, 44th Workshop on Geothermal Reservoir Engineering Stanford University, 11–13 February, Stanford, California, 2019 SGP-TR-214.
    [Google Scholar]
  15. Faulds, J.E., Hinz, N.H. et al.2021. Discovering Blind Geothermal Systems in the Great Basin Region: An Integrated Geologic and Geophysical Approach for Establishing Geothermal Play Fairways: All Phases. Technical Report, https://doi.org/10.2172/1724080
  16. Gloaguen, E., Marcotte, D., Chouteau, M. and Perroud, H.2005. Borehole radar velocity inversion using cokriging and cosimulation. Journal of Applied Geophysics, 57, 242–259, https://doi.org/10.1016/j.jappgeo.2005.01.001
    [Google Scholar]
  17. Gloaguen, E., Lefebvre, R., Ballard, J.M., Paradis, D., Tremblay, L. and Michaud, Y.2012. Inference of the two dimensional GPR velocity field using collocated cokriging of Direct Push permittivity and conductivity logs and GPR profiles. Journal of Applied Geophysics, 78, 94–101, https://doi.org/10.1016/j.jappgeo.2011.10.015
    [Google Scholar]
  18. Goovaerts, P.2001. Geostatistical modelling of uncertainty in soil science. Geoderma, 103, 3–26, https://doi.org/10.1016/S0016-7061(01)00067-2
    [Google Scholar]
  19. Gringarten, E. and Deutsch, C.V.2001. Teacher's aide variogram interpretation and modeling. Mathematical Geology, 33, 507–534, https://doi.org/10.1023/a:1011093014141
    [Google Scholar]
  20. Hansen, T.M., Journel, A.G., Tarantola, A. and Mosegaard, K.2006. Linear inverse Gaussian theory and geostatistics. Geophysics, 71, https://doi.org/10.1190/1.2345195
    [Google Scholar]
  21. Isaaks, E. and Srivastava, R.1989. An Introduction to Applied Geostatistics. Oxford Univ. Press, New York.
    [Google Scholar]
  22. Journel, A. and Huijbregts, C.1978. Mining Geostatistics. Academic Press, London.
    [Google Scholar]
  23. Koch, J., He, X., Jensen, K.H. and Refsgaard, J.C.2014. Challenges in conditioning a stochastic geological model of a heterogeneous glacial aquifer to a comprehensive soft data set. Hydrology and Earth System Sciences, 18, 2907–2923, https://doi.org/10.5194/hess-18-2907-2014
    [Google Scholar]
  24. Ma, X. and Journel, A.G.1999. An expanded GSLIB cokriging program allowing for two Markov models. Computers and Geosciences, 25, 627–639, https://doi.org/10.1016/S0098-3004(99)00009-6
    [Google Scholar]
  25. Nevada Bureau of Mines and Geology2017. Granite Springs Valley, Nevada Play Fairway Analysis - Well data and Temperature Survey [data set]. Retrieved from: Geothermal Data Repository, https://doi.org/10.15121/1452721
  26. Remy, N., Boucher, A. and Wu, J.2011. Applied Geostatistics with SGeMS: A User's Guide. Cambridge University Press.
    [Google Scholar]
  27. Shannon, C.E.1948. A mathematical theory of communication. The Bell System Technical Journal, 27, 379–423, https://doi.org/10.1002/j.1538-7305.1948.tb01338.x
    [Google Scholar]
  28. Siler, D.L. and Faulds, J.E.2013. Three-dimensional geothermal fairway mapping: examples from the Western Great Basin, USA. Geothermal Research Council Transactions, 37, 327–332, https://publications.mygeoenergynow.org/grc/1030589.pdf
    [Google Scholar]
  29. Siler, D.L. and Pepin, J.D.2021. 3-D geologic controls of hydrothermal fluid flow at brady geothermal field, Nevada, USA. Geothermics, 94, 102112, https://doi.org/10.1016/j.geothermics.2021.102112
    [Google Scholar]
  30. Siler, D.L., Hinz, N.H. and Faulds, J.E.2018. Stress concentrations at structural discontinuities in active fault zones in the western United States: implications for permeability and fluid flow in geothermal fields. Bulletin of the Geological Society of America, 130, 1273–1288, https://doi.org/10.1130/B31729.1
    [Google Scholar]
  31. Sullivan, C. and Trainor-Guitton, W.2019. PVGeo: an open-source Python package for geoscientific visualization in VTK and ParaView. Journal of Open Source Software, 4, 1451, https://doi.org/10.21105/joss.01451
    [Google Scholar]
  32. Webster, R. and Oliver, M.A.2008. Geostatistics for Environmental Scientists. 2nd edn., 1–315.
    [Google Scholar]
  33. Williams, C. and DeAngelo, C.2011. Evaluation of approaches and associated uncertainties in the estimation of temperatures in the upper crust of the western United States. Geothermal Research Council Transactions, 35, 1599–1606, https://publications.mygeoenergynow.org/grc/1029460.pdf
    [Google Scholar]
  34. Witter, J.B., Trainor-Guitton, W.J. and Siler, D.L.2019. Uncertainty and risk evaluation during the exploration stage of geothermal development: a review. Geothermics, 78, 233–242, https://doi.org/10.1016/j.geothermics.2018.12.011
    [Google Scholar]
  35. Zhu, H. and Journel, A.G.1993. Formating and integrating soft data: stochastic imaging via the Markov-Bayes Algorithm. In:Soares, A. (ed.) Geostatistics Troia ’92. Kluwer Acad., Norwell, Mass., 1–11.
    [Google Scholar]
/content/journals/10.1144/geoenergy2023-010
Loading
/content/journals/10.1144/geoenergy2023-010
Loading

Data & Media loading...

  • Article Type: Research Article
This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error