Abstract
Stimulating carbonate reservoirs by injecting acids results in channels within the rock called wormholes. This study reveals the stability of wormholed chalk and limestone samples under high confining pressure using a triaxial cell. The experiments were conducted on four Austin chalk (AC) and four Indiana limestone (IL) core samples (1.5 inches × 3 inches). The samples were characterized by their petrophysical (i.e., porosity and permeability) and elastic properties (i.e., Young’s modulus). Two of each rock type were acidized to generate wormholes using a core flooding setup. Then the samples were subjected to a high confining pressure of up to 88 MPa using a triaxial/acoustic cell. In addition, the permeability of the samples under increasing confining pressure was reported. Medical CT scan images were taken for the wormholed samples before and after subjecting them to high confining pressures. The CT scan images and rock properties were imported to COMSOL finite element to simulate the deformation under high stresses. The results revealed that wormholes closed under confining in the chalk samples while it was mechanically stable in the IL samples. This was attributed to the rigidity of limestone as compared to weak chalk samples. Fractures were observed in one of the chalk samples, while no fractures were noticed in the limestone. The finite element simulations confirmed the experimental outcomes and showed that the wormhole branches were more susceptible to deformation and closure.
Highlights
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Wormholes in weak carbonate rocks are subject to closure under high confining pressures
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Wormhole branches tend to close faster due to the higher stress concentration
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Permeability of the wormhole is a strong function of the confining pressure
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References
Abass, H. H., Al-Mulhem, A. A., Alqam, M. S., & Mirajuddin, K. R. (2006, September 24). Acid Fracturing or Proppant Fracturing in Carbonate Formation? A Rock Mechanic’s View. SPE Annual Technical Conference and Exhibition. https://doi.org/10.2118/102590-MS
Alameedy U, Alhaleem AA, Isah A, Al-Yaseri A, Mahmoud M, Salih IS (2022) Effect of acid treatment on the geomechanical properties of rocks: An experimental investigation in Ahdeb oil field. J Petrol Explor Prod Technol 12(12):3425–3441. https://doi.org/10.1007/s13202-022-01533-x
Al-Arji H, Al-Azman A, Le-Hussain F, Regenauer-Lieb K (2021) Acid stimulation in carbonates: A laboratory test of a wormhole model based on Damköhler and Péclet numbers. J Petrol Sci Eng 203:108593. https://doi.org/10.1016/j.petrol.2021.108593
Aldhayee K, Ali MT, Nasr-El-Din HA (2020) Modeling wormhole propagation during closed-fracture-acidizing stimulation in tight-carbonate formations. SPE J 25(05):2373–2400. https://doi.org/10.2118/201252-PA
Barri A, Hassan A, Aljawad M, Mahmoud M (2021) Effect of treatment conditions on matrix stimulation of carbonate rocks with chelating agents. Arab J Sci Eng. https://doi.org/10.1007/s13369-021-05633-4
Dong K (2018) A new wormhole propagation model at optimal conditions for carbonate acidizing. J Petrol Sci Eng 171:1309–1317. https://doi.org/10.1016/j.petrol.2018.08.055
Fjaer, E., Holt, R.M., Raaen, A.M., Horsrud, P., 2008. Petroleum Related Rock Mechanics, seconded. Elsevier Science, p. 53.
Fredd CN, Fogler HS (1998) Influence of transport and reaction on wormhole formation in porous media. AIChE J 44(9):1933–1949. https://doi.org/10.1002/aic.690440902
Gou, B., Zeng, M., Guo, J., Lai, J., Liu, Z., Ma, H., Zhou, C., & Liu, F. (2019, August 5). Effects of Hydrochloric Acid on the Mechanical and Elastic Properties of Tight Dolomite. ARMA-CUPB Geothermal International Conference. https://onepetro.org/ARMACUPB/proceedings-abstract/CUPB19/All-CUPB19/125196
Jeffry SJM, Trjangganung K, Chandrakant AA, Madon B, Katende A, Ismail I (2020) Selection of suitable acid chemicals for matrix stimulation: A Malaysian Brown field scenario. J Petrol Sci Eng 186:106689. https://doi.org/10.1016/j.petrol.2019.106689
Li H, Shi Y (2021) Triaxial experimental investigation into the characteristics of acid-etched fractures and acid fracturing. J Petrol Sci Eng 202:108431. https://doi.org/10.1016/j.petrol.2021.108431
Liu M, Mostaghimi P (2017) Pore-scale simulation of dissolution-induced variations in rock mechanical properties. Int J Heat Mass Transf 111:842–851. https://doi.org/10.1016/j.ijheatmasstransfer.2017.04.049
Mahmoud M, Kamal MS, Aljawad MS, Ali A, Al-Nakhli A (2021) Single-stage stimulation of anhydrite-rich carbonate rocks using chelating agent: an experimental and modeling investigation. SPE J 26(03):1144–1160. https://doi.org/10.2118/203840-PA
Mustafa A, Aly M, Aljawad MS, Dvorkin J, Solling T, Sultan A (2021) A green and efficient acid system for carbonate reservoir stimulation. J Petrol Sci Eng 205:108974. https://doi.org/10.1016/j.petrol.2021.108974
Mustafa A, Alzaki T, Aljawad MS, Solling T, Dvorkin J (2022) Impact of acid wormhole on the mechanical properties of chalk, limestone, and dolomite: experimental and modeling studies. Energy Rep 8:605–616. https://doi.org/10.1016/j.egyr.2021.11.249
Mustafa A, Desouky M, Aljawad MS, Solling T, Dvorkin J (2023) Sustaining wormholes mechanical stability in weak acidized carbonates using consolidants. Rock Mech Rock Eng. https://doi.org/10.1007/s00603-023-03285-4
Ng K, Santamarina JC (2022) Mechanical and hydraulic properties of carbonate rock: The critical role of porosity. J Rock Mech Geotech Eng. https://doi.org/10.1016/j.jrmge.2022.07.017
Omer, M., Fragachan, F. E., & Rodriguez, C. C. (2020, November 9). No More Premature Collapse of Acid Wormholes: Extend Wells Productivity with Particulate Diversion Technique Modelling. Abu Dhabi International Petroleum Exhibition & Conference. https://doi.org/10.2118/202670-MS
Xue H, Huang Z, Zhao L, Wang H, Kang B, Liu P, Liu F, Cheng Y, Xin J (2018) Influence of acid-rock reaction heat and heat transmission on wormholing in carbonate rock. J Nat Gas Sci Eng 50:189–204. https://doi.org/10.1016/j.jngse.2017.12.008
Zhang H, Zhong Y, Zhang J, Zhang Y, Kuang J, Yang B (2020) Experimental research on deterioration of mechanical properties of carbonate rocks under acidified conditions. J Petrol Sci Eng 185:106612. https://doi.org/10.1016/j.petrol.2019.106612
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Algarni, S., Aljawad, M.S., Al-Majid, H. et al. Stability of Carbonate Rocks Containing Acid Wormholes Under High Confining Pressures. Rock Mech Rock Eng 57, 219–231 (2024). https://doi.org/10.1007/s00603-023-03568-w
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DOI: https://doi.org/10.1007/s00603-023-03568-w