Geological Sequestration in Tight Reservoirs with Different Fracturing Schemes: Weiyuan Gas Field, Sichuan Basin, China

Zhiming Chen; Laibin Zhang; Xurong Zhao; Xin Gao; Kamy Sephernoori

doi:10.1016/j.eng.2025.08.038

Engineering ›› DOI: 10.1016/j.eng.2025.08.038

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Geological Sequestration in Tight Reservoirs with Different Fracturing Schemes: Weiyuan Gas Field, Sichuan Basin, China

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Abstract

Tight gas reservoirs are promising candidates for CO₂ geological sequestration. However, the fracturing treatments used for production may compromise the integrity of the caprock and increase the risk of gas leakage. This study examines the impact mechanisms of different fracturing schemes on caprock safety during CO₂ sequestration in tight reservoirs to optimize sequestration strategies and provide theoretical support. Using a developed CO₂ sequestration model, we systematically evaluate the leakage characteristics of caprock under various fracturing schemes. For the first time, this study introduces the use of the Analytically Modified Embedded Discrete Fracture Model (AEDFM) to describe the flow interactions between fractures and the matrix during long-term CO₂ sequestration. Through an in-depth analysis of critical factors such as the different mechanisms of fracture parameters, sand concentration, flow rate, and fracturing fluid viscosity, we comprehensively evaluate how these fracturing schemes influence caprock safety for a case study. Validation results confirm that the AEDFM method successfully overcomes the low accuracy exhibited by the Embedded Discrete Fracture Model (EDFM) in simulating early-time transient flow. The proposed CO₂ sequestration model demonstrates strong agreement with production history matching performed using commercial software, affirming its reliability and practical applicability. The results from a case study show that increasing the number, half-length, and height of hydraulic fractures in fracturing designs will increase the risk of CO₂ leakage, thereby compromising caprock safety. If hydraulic fractures penetrate the caprock, the risk of CO₂ leakage through the top caprock markedly increases. In scenarios where fractures do not penetrate the caprock, the volume of leaked CO₂ over a 100-year sequestration period remains below 5 % of the injected gas. However, leakage can rise to as much as 12 % if caprock penetration occurs. Furthermore, increasing the flow rate and sand concentration and decreasing the viscosity lead to larger fracture dimensions, further increasing the risk of CO₂ leakage and diminishing caprock safety. An investigation of various mechanisms affecting caprock safety reveals that heterogeneity-controlled preferential flow and hydrochemical reactions tend to compromise caprock safety, while capillary forces and stress-sensitive fracture behavior increase sealing capacity. This study offers theoretical insights and practical guidance for CO₂ sequestration in tight reservoirs.

Keywords

Caprock safety / CO₂ sequestration / Leakage risk / Tight reservoirs

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Zhiming Chen, Laibin Zhang, Xurong Zhao, Xin Gao, Kamy Sephernoori. Geological Sequestration in Tight Reservoirs with Different Fracturing Schemes: Weiyuan Gas Field, Sichuan Basin, China. Engineering DOI:10.1016/j.eng.2025.08.038

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References

Publishing order | Descend order by publishing year | Descend order by cited within

[1]	Wang X, Yang H, Huang Y, Liang Q, Liu J, Ye D.Evolution of CO₂ storage mechanisms in low-permeability tight sandstone reservoirs.Engineering 2025; 48:107-120.

[2]	Chen Q, Hou J, Wei B, Gong R, Du Q, Liu Y.Study on CO₂ storage suitability evaluation and storage potential prediction method in site-level saline aquifer: a case study of X saline aquifer block in Enping 15–1 oilfield.Geoenergy Sci Eng 2025; 246:213598.

[3]	Meng S, Zhang F, Tao J, Jin X, Xu J, Liu H.Carbon storage potential of shale reservoirs based on CO₂ fracturing technology.Engineering 2025; 48:121-127.

[4]	Jing H, Pan H, Sun R, Liu J, Fang Z.Artificial neural network-based three-phase equilibria computation in compositional simulation of EOR and storage of CO₂ in low-temperature reservoir.Geoenergy Sci Eng 2025; 246:213542.

[5]	Lee J, Yun S, Mun S, Mok J, Choi W, Seo Y.Experimental and computational investigation of guest encapsulation and structural transformation behaviors in C₃H₈ hydrate—CO₂ replacement for energy recovery and CO₂ sequestration.Fuel 2025; 385:134123.

[6]	Zhang Y, Qu M, Yang J, Sajjad F, Ben N, Yu Z, et al.Prediction of CO₂ storage efficiency and its uncertainty using deep-convolutional GANs and pore network modelling.Appl Energy 2025; 381:125142.

[7]	Mirzaei-Paiaman A, Okuno R.Critical review on wettability, optimal wettability, and artificial wettability alteration in rock–brine–CO₂ systems for geologic carbon sequestration.Gas Sci Engi 2024; 132:205499.

[8]	Al-Rbeawi S.Pressure distributions and flow regimes: an integrated approach for CO₂ sequestration project design and evaluation in hydraulically fractured shale reservoirs.Gas Sci Eng 2025; 133:205495.

[9]

Khosravi M, Askari Z, Okwen RT, Taft K.Evaluating the regional geological characteristics of the St. Peter sandstone and Everton formation for CO₂ storage in southern Illinois: a case study on site-specific injection feasibility in Washington County, Illinois.Int J Greenh Gas Control 2025; 141:104292.

[10]	Gu Y, Liu X, Li Y, Lu H, Xu C, Ren J, et al.Feasibility analysis of liquid CO₂ injection and sequestration as hydrates in South China Sea marine sediments over 100 years.Appl Energy 2025; 380:125068.

[11]	Longe P, Molomjav S, Tsau JS, Musgrove S, Villalobos J, D J’Erasmo, et al.Techno-economic evaluation of CO₂-EOR and carbon storage in a shallow incised fluvial reservoir using captured-CO₂ from an ethanol plant.Geoenergy Sci Eng 2025; 246:213559.

[12]	Kouhi MM, Kahzadvand K, Shahin M, Shafiei A.New connectionist tools for prediction of CO₂ diffusion coefficient in brine at high pressure and temperature—implications for CO₂ sequestration in deep saline aquifers.Fuel 2025; 384:134000.

[13]	Davoodi S, Thanh HV, Wood DA, Mehrad M, Al-Shargabid M, Rukavishnikov VS.Committee machine learning: a breakthrough in the precise prediction of CO₂ storage mass and oil production volumes in unconventional reservoirs.Geoenergy Sci Eng 2025; 245:213533.

[14]	Liu S, Zhang Y, Zhao Y, Wang Z, Song Y, Lv J.Study of displacement behavior and dispersion characteristics based on low-field NMR in the context of CO₂ geological sequestration and enhanced methane recovery.Fuel 2024; 373:132332.

[15]	Lu X, Jordan KE, Wheeler MF, Pyzer-Knapp EO, Benatan M.Bayesian optimization for field-scale geological carbon storage.Engineering 2022; 18(11):96-104.

[16]	Kumar AD, Hassan H.Analytical solutions for brine invasion across caprock and leakage through an abandoned well in CO₂ storage sites.J Hydrol 2023; 625:130046.

[17]	Newell P, Martinez M.Numerical assessment of fault impact on caprock seals during CO₂ sequestration.Int J Greenh Gas Control 2020; 94:102890.

[18]	Frash PL, Carey WJ, Ickes TS, Viswanathan H.Caprock integrity susceptibility to permeable fracture creation.Int J Greenh Gas Control 2017; 64:60-72.

[19]	Zhao G, Zheng J, Gong G, Chen B, Yang M, Song Y.Formation characteristics and leakage termination effects of CO₂ hydrate cap in case of geological sequestration leakage.Appl Energy 2023; 351:121896.

[20]	Zhu S, Zheng D, Sun J, Wei G, Wu Z, Wang J, et al.Experimental study on dynamic sealing capacity and safe threshold of caprock in underground gas storages.J Nat Gas Sci Eng 2022; 101:104521.

[21]	Raziperchikolaee S, Pasumarti A.The impact of the depth-dependence of in-situ stresses on the effectiveness of stacked caprock reservoir systems for CO₂ storage.J Nat Gas Sci Eng 2020; 79:103361.

[22]	Perera MSA, Ranjith PG, Choi SK, Bouazza A.A parametric study of coal mass and cap rock behaviour and carbon dioxide flow during and after carbon dioxide injection.Fuel 2013; 106:129-138.

[23]	Yang M, Wu M, Yang Z, Wang P, Chen B, Song Y.Behaviors of hydrate cap formation via CO₂–H₂O collaborative injection: applying to secure marine carbon storage.Gas Sci Eng 2024; 131:205451.

[24]	Zhang B.A prediction method for hydrocarbon distribution associated with fault-shale caprock configuration leakages.Energies 2022; 15(8):2867.

[25]	S Młota-Valim, Go Ałąbek, Szott W, Sowi Kżdżał.Analysis of caprock tightness for CO₂ enhanced oil recovery and sequestration: case study of a depleted oil and gas reservoir in Dolomite, Poland.Energies 2021; 14(11):3065.

[26]	Qiao T, Hoteit H, Fahs M.Semi-analytical solution to assess CO₂ leakage in the subsurface through abandoned wells.Energies 2021; 14(9):2452.

[27]	Singh H, Dilmore RM.Stochastic prediction of fractured caprock by history matching pressure monitoring data.J Petrol Sci Eng 2019; 179:615-630.

[28]	Mosaheb M, Zeidouni M.Above zone pressure interpretation for leaky well characterization and its identification from leaky caprock/fault.J Petrol Sci Eng 2018; 171:218-228.

[29]	Wang J, Peng Y.Numerical modeling for the combined effects of two-phase flow, deformation, gas diffusion and CO₂ sorption on caprock sealing efficiency.J Geochem Explor 2014; 144:154-167.

[30]	Shang X, Wang J, Wang H, Wang X.Combined effects of CO₂ adsorption-induced swelling and dehydration-induced shrinkage on caprock sealing efficiency.Int J Environ Res Public Health 2022; 19(21):14574.

[31]	Tian H, Pan F, Xu T, McPherson BJ, Yue G, Mandalaparty P.Impacts of hydrological heterogeneities on caprock mineral alteration and containment of CO₂ in geological storage sites.Int J Greenh Gas Control 2014; 24:30-42.

[32]

Zhang K, Sang S, Zhou X, Liu C, Ma M, Niu Q.Influence of supercritical CO₂–H₂O–caprock interactions on the sealing capability of deep coal seam caprocks related to CO₂ geological storage: a case study of the silty mudstone caprock of coal seam NO. 3 in the Qinshui Basin.China Int J Greenh Gas Control 2021; 106:103282.

[33]	Zhao X, Chen Z, Zhang L, Liao X, Awotunde AA.Leakage risk assessment on sealing efficiency of caprock during CO₂ huff-n-puff for safe sequestration.Geoenergy Sci Eng 2024; 240:213056.

[34]

Shi L, Song P, Zhao X, Shi J, Shi B, Zhao X, et al.2024. Sealing efficiency of caprock in fractured tight reservoirs considering multi-migration mechanism simulated using improved EDFM. In: Proceedings of SPE International Health, Safety, Environment and Sustainability Conference and Exhibition; 2024 Sep 10–12; Abu Dhabi, USA. Richardson: OnePetro; 2024.

[35]	Kuang N, Zhou J, Xian X, Zhang C, Yang K, Dong Z.Geomechanical risk and mechanism analysis of CO₂ sequestration in unconventional coal seams and shale gas reservoirs.Rock Mech Bull 2023; 2(4):100079.

[36]	Wang H, Wu T, Fu X, Liu B, Wang S, Jia R, et al.Quantitative determination of the brittle–ductile transition characteristics of caprocks and its geological significance in the Kuqa depression, Tarim Basin, western China.J Petrol Sci Eng 2019; 173:492-500.

[37]	Guiltinan EJ, Espinoza DN, Cockrell LP, Cardenas MB.Textural and compositional controls on mudrock breakthrough pressure and permeability.Adv Water Resour 2018; 121(11):162-172.

[38]	Han X, Feng F, Cong Z.Dynamic evaluation method of caprock microscopic sealing in CO₂ sequestration project.Geofluids 2020; 2020:2648692.

[39]	Liang M, Fu G, Li Q, Guo H, Zhang B.Fault evolution and its effect on the sealing ability of mudstone cap rocks.Energies 2022; 15(20):7676.

[40]	Wang L, Bai B, Li X, Liu M, Wu H, Hu S.An analytical model for assessing stability of pre-existing faults in caprock caused by fluid injection and extraction in a reservoir.Rock Mech Rock Eng 2016; 49(7):2845-2863.

[41]	Sun H, Jia C, Xiong F, Wu Z.Numerical modelling of CO₂ leakage through fractured caprock using an extended numerical manifold method.Eng Anal Bound Elem 2024; 162:327-336.

[42]	Fu P, Ju X, Huang J, Settgast RR, Liu F, Morris JP.Thermo–poroelastic responses of a pressure-driven fracture in a carbon storage reservoir and the implications for injectivity and caprock integrity.Int J Numer Anal Meth Geomech 2021; 45(6):719-737.

[43]	Lee SH, Lough MF, Jensen CL.Hierarchical modeling of flow in naturally fractured formations with multiple length scales.Water Resour Res 2001; 37(3):443-455.

[44]	Xu Y.Implementation and application of the embedded discrete fracture model (EDFM) for reservoir simulation in fractured reservoirs [dissertation]. The University of Texas at Austin, Austin (2015)

[45]	Zhao X, Chen Z, Wang B, Liao X, Li D, Zhou BA.Multi-medium and multi-mechanism model for CO₂ injection and storage in fractured shale gas reservoirs.Fuel 2023; 345:128167.

[46]	Moinfar A, Varavei A, Sepehrnoori K, Johns RT.Development of an efficient embedded discrete fracture model for 3D compositional reservoir simulation in fractured reservoirs.SPE J 2013; 19(2):289-303.

[47]	Mo W, Jiang Y, Li Y, Chang T, Liu K.Non-isothermal simulation of wormhole propagation in fractured carbonate rocks based on 3D-EDFM.Geoenergy Sci Eng 2025; 244:213453.

[48]	Poli REB, Barbosa MVMachado, Sepehrnoori K.Advancements and perspectives in embedded discrete fracture models (EDFM).Energies 2024; 17(14):3550.

[49]	Zheng J, Jiang T, Chen X, Cui Z, Jiang S, Song F, et al.Compositional simulation of CO₂ huff-n-puff processes in tight oil reservoirs with complex fractures based on EDFM technology considering the threshold pressure gradient.Energies 2023; 16(22):7538.

[50]	Bai Y, Hou J, Clarke MA, Zhao E, Zhang B, Liu Y.Numerical simulation on reservoir stimulation assisted depressurization development of hydrate bearing layers based on embedded discrete fractures.Geoenergy Sci Eng 2024; 241:213112.

[51]	Xiang Z, Zhen R, Xu Y, Wang S, Ao X, Chen Z, et al.A numerical pressure transient model of fractured well with complex fractures of tight gas reservoirs considering gas–water two phase by EDFM.Geoenergy Sci Eng 2023; 231:212286.

[52]	Liu W, Zeng Q, Yao J, Liu Z, Li T, Yan X.Numerical study of elasto–plastic hydraulic fracture propagation in deep reservoirs using a hybrid EDFM–XFEM Method.Energies 2021; 14(9):2610.

[53]	Chang C, Liu C, Li Y, Li X, Yu W, Miao J, et al.A novel optimization workflow coupling statistics-based methods to determine optimal well spacing and economics in shale gas reservoir with complex natural fractures.Energies 2020; 13(15):3965.

[54]	Shao R, Di Y, Wu D, Wu YS.An integrally embedded discrete fracture model for flow simulation in anisotropic formations.Energies 2020; 13(12):3070.

[55]	Xu J, Zhou W, Li H.Efficient production optimization for naturally fractured reservoir using EDFM.Petrol Sci 2023; 20(4):2268-2281.

[56]	Yu W, Hu X, Liu M, Wang W.Investigation of the effect of natural fractures on multiple shale-gas well performance using non-intrusive EDFM technology.Energies 2019; 12(5):932.

[57]	Olorode O, Rashid H.Analytical modification of EDFM for transient flow in tight rocks.Sci Rep 2022; 12(1):22018.

[58]	Zhou B, Chen Z, Song Z, Tang Z, Wang B, Olorode O.A new analytically modified embedded discrete fracture model for pressure transient analysis in fluid flow.J Hydrol 2024; 636:131330.

[59]	Liang X, Liu S, Wang S, Deng B, Zhou S, Ma W.Analysis of the oldest carbonate gas reservoir in China—new geological significance of the Dengying gas reservoir in the Weiyuan structure.Sichuan Basin J Earth Sci 2019; 30(2):348-366.

[60]	Mgimba MM, Jiang S, Ngole W.Optimization of hydraulic fracture treatment parameters for normally pressured Longmaxi and Wufeng Shales in the Southeastern Sichuan Basin in China.J Energy Eng 2023; 149(2):04023004.

[61]	Nadege NM, Shu B, Kouassi FKA, Ngungu MB, Mwakipunda GC, Harold KP, et al.Fracture toughness prediction using well logs and extreme gradient boosting based on particle swarm optimization in shale gas reservoir.Eng Fract Mech 2025; 315:110759.

[62]

Ngoy MN, Shu J, Charles GM, Kouassi FKA, Harold KP, Yao KRH.Brittleness index prediction using modified random forest based on particle swarm optimization of Upper Ordovician Wufeng to Lower Silurian Longmaxi shale gas reservoir in the Weiyuan Shale Gas Field, Sichuan Basin.China Geoenergy Sci Eng 2024; 233:212518.

[63]	Lie KA.An introduction to reservoir simulation using MATLAB/GNU octave: user guide for the MATLAB reservoir simulation toolbox (MRST). Cambridge University Press, Cambridge (2019)

[64]	Crouch SL.Solution of plane elasticity problems by the displacement discontinuity method.Int J Numer Meth Eng 1976; 10(2):301-343.

[65]	Wu K, Olson JE.Simultaneous multifracture treatments: fully coupled fluid flow and fracture mechanics for horizontal wells.SPE J 2014; 20(2):337-346.

[66]	Olson JE.Predicting fracture swarms—the influence of subcritical crack growth and the crack-tip process zone on joint spacing in rock.Spec Publ Geol Soc Lond 2004; 231(1):73-88.

[67]	Erdogan F, Sih GC.On the crack extension in plates under plane loading and transverse shear.J Basic Eng 1963; 85(4):519-525.

[68]	Elbel JL, Piggott AR, Mack MG.Numerical modeling of multilayer fracture treatments.In: Proceedings of Permian Basin Oil and Gas Recovery Conference; 1992 Mar 18–20; Midland, Texas. Richardson: OnePetro; 1992.

[69]	Zhao X, Chen Z, Zhou B, Liao X, Wang H, Wang B.Multiple flow mechanism-based numerical model for CO₂ huff-n-puff in shale gas reservoirs with complex fractures.Energy Fuels 2023; 37(12):8374-8385.

[70]	Pruess K, Wu YS.A new semi-analytical method for numerical simulation of fluid and heat flow in fractured reservoirs.Adv Technol Ser 1993; 1(2):63-72.

[71]	Zimmerman RW, Chen G, Hadgu T, Bodvarsson GS.A numerical dual-porosity model with semianalytical treatment of fracture/matrix flow.Water Resour Res 1993; 29(7):2127-2137.

[72]	Vermeulen T.Theory for irreversible and constant-pattern solid diffusion.Ind Eng Chem 1953; 45(8):1664-1670.

[73]	Tene M, Bosma SBM, Al MSKobaisi, Hajibeygi H.Projection-based embedded discrete fracture model (pEDFM).Adv Water Resour 2017; 105:205-216.

[74]	Huang G, Li M, Zhou F, Chu J, Xiong Z.A new numerical simulation method for multi-stage in-fracture temporary plugging and diverting fracturing: based on the modified cohesive zone model.Rock Mech Rock Eng 2024; 57(10):8723-8740.

[75]	Li L, Zhou F, Zhou Y, Cai Z, Wang B, Zhao Y, et al.The prediction and optimization of hydraulic fracturing by integrating the numerical simulation and the machine learning methods.Energy Rep 2022; 8:15338-15349.

[76]	Müller S, Schüler L, Zech A, He Fße.Gstools v1. 3: a toolbox for geostatistical modelling in Python.Geosci Model Dev 2022; 15(7):3161-3182.

[77]	Muhammad A, Bin P, Nurudeen Y, Al-Anssari S, Keshavarz A, Iglauer S, et al.Assessment of wettability and rock–fluid interfacial tension of caprock: implications for hydrogen and carbon dioxide geo-storage.Int J Hydrogen Energy 2022; 47(30):14104-14120.

[78]	Zeng F, Jiang J, Hu D, Tian F, Guo J, Zhang Q, et al.Research on an effective permeability prediction method for shale reservoirs based on imbibition experiments.Arab J Geosci 2024; 17(4):116.

[79]	Gangi AF.Variation of whole and fractured porous rock permeability with confining pressure.Int J Rock Mech Min Sci Geomech Abstr 1978; 15(5):249-257.

[80]	Spivey JP, McCain WDJr, North R.Estimating density, formation volume factor, compressibility, methane solubility, and viscosity for oilfield brines at temperatures from 0 to 275 °C, pressures to 200 MPa, and salinities to 5.7 mole/kg.J Can Pet Technol 2004; 43(7):52-61.