Skip to main content
SpringerLink
Log in

Evaluation of Parameters Influencing Potential Gas Flow to the Mine in the Event of a Nearby Unconventional Shale Gas Well Casing Breach

  • Published:
Mining, Metallurgy & Exploration Aims and scope Submit manuscript

Abstract

The integrity of unconventional shale gas well casings positioned in the abutment pillar of a longwall mine could be jeopardized by longwall-induced deformations. Under such scenarios, the surrounding fracture networks could provide pathways for gas flow into the mine creating safety concerns. To provide recommendations for developing guidelines that ensure a safe co-existence of longwall mining and unconventional shale gas production, this study evaluates the impact of parameters that could affect potential shale gas flow into the mine in the event of a casing breach using a discrete fracture network (DFN) model. These parameters are evaluated using a conceptualized DFN realization that is representative of the fractured zone in the overburden, and the range of parameter variations is within values validated with field measurements. The results show that a decrease in fracture aperture (potentially due to longwall-induced stress in the likely vicinity of the breach location) reduces the potential gas flow to the mine by a significantly higher proportion. A 50% decrease in the aperture of the fracture that directly transports the gas from the casing breach location reduces the gas flow to the mine by over 70%. Similarly, changes in the fracture water saturation level significantly affect the gas flow. In all cases, the potential gas flow to the mine is higher if the casing breach occurs at an increased gas well pressure. These findings provide critical information regarding the impact of each of the parameters associated with gas flow in the event of a shale gas casing breach near a longwall mine and could help towards the development of guidelines to ensure a safe coexistence of both industries.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6

Similar content being viewed by others

References

  1. Zhang P, Su D, Lu J (2019) Influence of longwall mining on the stability of shale gas wells in barrier pillars. in American Rock Mechanics Association. New York

  2. Commonwealth of Pennsylvania Department of Mines and Mineral Industries and Oil and Gas Division (1957), Joint coal and gas committee, gas well pillar study. Harrisburg, p 28

  3. Pennsylvania Department of Environmental Protection, Longwall mine data.  Available from: https://www.dep.state.pa.us/dep/deputate/minres/LongwallForestlandStudy/Table1.pdf. [cited 29 09 2021]

  4. Berryhill HL. Coal Reserves of the Pittsburgh (no. 8) Bed in Belmont County, Ohio. Vol. 363. 1955

  5. Schatzel SJ, Karacan CÖ, Dougherty H, Goodman GV (2012) An analysis of reservoir conditions and responses in longwall panel overburden during mining and its effect on gob gas well performance. Eng Geol 127:65–74

    Article  Google Scholar 

  6. Leung C, Hoch A, Zimmerman R (2012) Comparison of discrete fracture network and equivalent continuum simulations of fluid flow through two-dimensional fracture networks for the DECOVALEX–2011 project. Mineral Mag 76(8):3179–3190

    Article  Google Scholar 

  7. Rutqvist J, Figueiredo B, Hu M, Tsang C-F (2018) Continuum modeling of hydraulic fracturing in complex fractured rock masses, in Hydraulic Fracture Modeling. Elsevier, p 195–217

  8. Liu H-H, Haukwa CB, Ahlers CF, Bodvarsson GS, Flint AL, Guertal WB (2003) Modeling flow and transport in unsaturated fractured rock: an evaluation of the continuum approach. J Contam Hydrol 62:173–188

    Article  Google Scholar 

  9. Ajayi K M, Shahbazi K, Tukkaraja P, & Katzenstein K (2019) Prediction of airway resistance in panel cave mines using a discrete and continuum model. Int J Min Sci Technol

  10. Carrillo FJ, Bourg IC, Soulaine C (2020) Multiphase flow modeling in multiscale porous media: an open-source micro-continuum approach. J Comput Phys: X 8:100073

    MathSciNet  Google Scholar 

  11. Doolin D, Mauldon M (2001) Fracture permeability normal to bedding in layered rock masses. Int J Rock Mech Min Sci 38(2):199–210

    Article  Google Scholar 

  12. Ajayi K, Khademian Z, Schatzel S, Watkins E, Gangrade V (2021) Numerical modeling of longwall-induced permeability under shallow cover, in Mine Ventilation. CRC Press, p 389–397

  13. Watkins E, Karacan C Ö, Gangrade V, Schatzel S (2021) Assessing gas leakage potential into coal mines from shale gas well failures: inference from field determination of strata permeability responses to longwall-induced deformations. Nat Resour Res, p 1–14

  14. Khademian Z, Ajayi K M, Su D W H, Esterhuizen G, Schatzel S J (2021) Geomechanical modeling of mining-induced permeability: implications for potential gas inflow from a sheared gas well. Canonsburg

  15. Priest SD (2012) Fluid flow in discontinuities, in Discontinuity analysis for rock engineering. Springer Science & Business Media

  16. Ajayi K M, & Schatzel S J (2020) Transport model for shale gas well leakage through the surrounding fractured zones of a longwall mine. Int J Min Sci Technol

  17. Su D, Zhang P, Dougherty H, Van Dyke M, Minoski T, Schatzel S, Gangrade V, Watkins E, Addis J, Hollerich C (2019) Longwall-induced subsurface deformations and permeability changes—shale gas well casing integrity implication. in Proceedings of the 38th International Conference on Ground Control in Mining. Society for Mining, Metallurgy & Exploration

  18. Ajayi KM, Schatzel SJ (2020) Transport model for shale gas well leakage through the surrounding fractured zones of a longwall mine. Int J Min Sci Technol 30(5):635–641

    Article  Google Scholar 

  19. Ranjith P, Viete D (2011) Applicability of the ‘cubic law’for non-Darcian fracture flow. J Petrol Sci Eng 78(2):321–327

    Article  Google Scholar 

  20. Kissell F N, Edwards J C (1975) Two-phase flow in coalbeds

  21. Zabetakis M G (1972) Methane emission in coal mines: effects of oil and gas wells. Vol. 7658. US Department of Interior, Bureau of Mines

  22. Mark C (1990) Pillar design methods for longwall mining. Vol. 9247. US Department of the Interior, Bureau of Mines

  23. Khademian Z, Ajayi K M, Schatzel S J, Esterhuizen G S, Kim B H (2022) Rockmass permeability induced by longwall mining under deep cover: potential gas inflow from a sheared gas well. Mining, Metallurgy & Exploration, p 1–9

  24. Ajayi K, Khademian Z, Schatzel S, Watkins E, Gangrade V (2022) A discrete fracture network model for prediction of longwall-induced permeability. Mining, Metallurgy & Exploration, p 1–8

Download references

Acknowledgements

The data from this manuscript have been presented at the MINEXCHANGE 2022 SME Annual Conference & Expo, February 27–March 2, 2022, Salt Lake City, Utah.

Author information

Authors and Affiliations

  1. CDC NIOSH, Pittsburgh, PA, USA

    Kayode M. Ajayi, Zoheir Khademian & Steven J. Schatzel

Authors
  1. Kayode M. Ajayi
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Zoheir Khademian
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Steven J. Schatzel
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to Kayode M. Ajayi.

Ethics declarations

Conflict of Interest

The authors declare no competing interests.

Disclaimer

The findings and conclusions in this manuscript are those of the authors and do not necessarily represent the official position of the National Institute for Occupational Safety and Health (NIOSH), Centers for Disease Control and Prevention (CDC). The mention of company names or products does not constitute endorsement by NIOSH or CDC.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Ajayi, K.M., Khademian, Z. & Schatzel, S.J. Evaluation of Parameters Influencing Potential Gas Flow to the Mine in the Event of a Nearby Unconventional Shale Gas Well Casing Breach. Mining, Metallurgy & Exploration 39, 2333–2341 (2022). https://doi.org/10.1007/s42461-022-00680-3

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s42461-022-00680-3

Search

Navigation