{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,8]],"date-time":"2026-09-08T14:07:21Z","timestamp":1788876441397,"version":"build-2803163510"},"reference-count":50,"publisher":"American Chemical Society (ACS)","issue":"35","license":[{"start":{"date-parts":[[2026,8,21]],"date-time":"2026-08-21T00:00:00Z","timestamp":1787270400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100011710","name":"Shaanxi Provincial Science and Technology Department","doi-asserted-by":"publisher","award":["2023-JC-QN-0350"],"award-info":[{"award-number":["2023-JC-QN-0350"]}],"id":[{"id":"10.13039\/501100011710","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/na","name":"State Key Laboratory of Oil and Gas Reservoir Geology and Exploration, Southwest Petroleum University","doi-asserted-by":"publisher","award":["PLN2020-15"],"award-info":[{"award-number":["PLN2020-15"]}],"id":[{"id":"10.13039\/na","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,9,8]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Hydraulic fracturing is the primary method for developing tight sandstone reservoirs. In particular, horizontal well staged fracturing huff-n-puff is the main technique for enhancing oil recovery in tight sandstones. To clarify the remaining oil distribution and oil displacement mechanism under this technological background, this paper starts from the microscopic seepage mechanism and conducts systematic research by combining microscopic experiments, macroscopic displacement analysis, and numerical simulation. The simple capillary number model is improved for tight reservoirs, revealing that the core mechanism of imbibition is capillary force. To study the coupled imbibition-displacement mechanism in tight reservoirs, visualization oil displacement experiments using glass etching models were carried out, and the oil\u2013water migration under coupled imbibition-displacement was analyzed. The results show that the sweep range of imbibition is much smaller than that of displacement, and the higher the water-wetness, the less the remaining oil during displacement and imbibition replacement. Based on this, conventional imbibition experiments were conducted using real oil-wet thin cores (0.5 cm), confirming that gravity is the main driving force for imbibition in real oil-wet cores, and the larger the contact area between the core and the liquid, the higher the imbibition rate. To eliminate the influence of gravity and analyze the effect of imbibition area, end-face imbibition and full-surface imbibition experiments were performed using thin cores (0.5 cm) and long cores (7.5 cm). The results indicate that imbibition in horizontal cores is mainly horizontal, and the relationship between contact area and imbibition rate was quantified. To analyze the displacement-imbibition oil enhancement in mixed-wet cores from multiple angles and by multiple means, digital rock technology was used to simulate the imbibition experiments on real cores. The main controlling factor for imbibition was identified as displacement pressure: under capillary imbibition and low-pressure drive, the oil displacement efficiency by imbibition is low, but the flowback ratio is high; under higher injection pressure, the imbibition efficiency increases while the flowback ratio decreases. Guided by the microscopic experimental mechanisms, a macroscopic model of horizontal well multistage fracturing was established using numerical simulation to analyze the factors influencing huff-n-puff and imbibition oil enhancement. The results show that after fracturing and well soaking in the study area, high-pressure drive is the main mechanism for oil\u2013water replacement; the optimal well soaking time is 3\u20134 months; for reservoirs with relatively low oil saturation, imbibition replacement during well soaking is the main means to enhance oil recovery.<\/jats:p>","DOI":"10.1021\/acsomega.6c03053","type":"journal-article","created":{"date-parts":[[2026,8,23]],"date-time":"2026-08-23T07:45:45Z","timestamp":1787471145000},"page":"52200-52213","source":"Crossref","is-referenced-by-count":0,"title":["Enhancement Mechanisms\nof Multi-Scale Huff-and-Puff\nin Horizontal Wells for Tight Sandstone Reservoirs-A Case Study\nof the Chang 63 Formation in the Wuqi Block, Ordos Basin"],"prefix":"10.1021","volume":"11","author":[{"given":"Xiaohui","family":"Zhang","sequence":"first","affiliation":[{"name":"Changqing Oilfield Company PetroChina , , , ,","place":["Xi\u2019an, Shaanxi, China, 710000"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yi","family":"Shi","sequence":"additional","affiliation":[{"name":"Changqing Oilfield Company PetroChina , , , ,","place":["Xi\u2019an, Shaanxi, China, 710000"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yanli","family":"Ma","sequence":"additional","affiliation":[{"name":"Changqing Oilfield Company PetroChina , , , ,","place":["Xi\u2019an, Shaanxi, China, 710000"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yicheng","family":"Wang","sequence":"additional","affiliation":[{"name":"Changqing Oilfield Company PetroChina , , , ,","place":["Xi\u2019an, Shaanxi, China, 710000"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5277-1147","authenticated-orcid":true,"given":"Juan","family":"Zhang","sequence":"additional","affiliation":[{"name":"Xi\u2019an Shiyou University , , , ,","place":["Xi\u2019an, Shaanxi, China, 710000"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"316","published-online":{"date-parts":[[2026,8,21]]},"reference":[{"issue":"05","key":"2026090809111567100_cit1","first-page":"1682","article-title":"Microfluidic experimental\nstudy on imbibition-displacement mechanism of tight oil reservoirs\nusing fracture-matrix etched chips","volume":"46","author":"Yang","year":"2025","journal-title":"Oil Gas\nGeol."},{"key":"2026090809111567100_cit2","doi-asserted-by":"publisher","DOI":"10.1038\/s41598-025-89676-9","article-title":"Mineral composition\nand pore structure on spontaneous imbibition\nin tight sandstone reservoirs","volume":"15","author":"Yang","year":"2025","journal-title":"Sci. Rep."},{"key":"2026090809111567100_cit3a","unstructured":"(a)\n          \n            \n              Jin, H.; Jiang, G.; Hou, L.; Cao, J.; Li, Y.; Liu, Z.\n          Influence law of surfactant interfacial properties\non imbibition\nin tight reservoirs\n          Pet. Geol. Oilfield Dev.\nDaqin\n          2025."},{"issue":"5","key":"2026090809111567100_cit4","first-page":"824","article-title":"Study on imbibition\nmechanisms in tight oil reservoirs based on nuclear magnetic resonance\nand pore-scale simulation","volume":"15","author":"Qi","year":"2025","journal-title":"Pet. Reservoir Eval.\nDev."},{"key":"2026090809111567100_cit5","unstructured":"Li, Y.; Qian, Q.; Peng, X.; Li, A.; Zhang, Y.\n          Influencing factors of spontaneous\nimbibition in\nsandstone reservoirs and its microscopic mechanism\n          Pet. Geol. Oilfield Dev. Daqin."},{"issue":"5","key":"2026090809111567100_cit6","doi-asserted-by":"publisher","DOI":"10.1063\/5.0209910","article-title":"Effect of initial water\nsaturation and water film on imbibition behavior in tight reservoirs\nusing nuclear magnetic resonance technique","volume":"36","author":"Meng","year":"2024","journal-title":"Phys. Fluids"},{"key":"2026090809111567100_cit7","doi-asserted-by":"publisher","DOI":"10.1016\/j.energy.2024.133244","article-title":"Experimental\nstudy on microscopic production characteristics\nand influencing factors during dynamic imbibition of shale reservoir\nwith online NMR and fractal theory","volume":"310","author":"Du","year":"2024","journal-title":"Energy"},{"issue":"3","key":"2026090809111567100_cit8","first-page":"64","article-title":"Research progress on\nenhancing oil recovery by imbibition","volume":"53","author":"Wang","year":"2024","journal-title":"Chem.\nEng. Oil Gas"},{"key":"2026090809111567100_cit9","doi-asserted-by":"publisher","first-page":"2866","DOI":"10.1021\/acs.energyfuels.3c04547","article-title":"Characterizing Residual Oil Distribution\nin Heavy Oil Reservoirs after Multiple Hot Water huff-n-puff: A Comprehensive\nAnalysis","volume":"38","author":"Mo","year":"2024","journal-title":"Energy Fuels"},{"issue":"22","key":"2026090809111567100_cit10","doi-asserted-by":"publisher","first-page":"13586","DOI":"10.1021\/acs.energyfuels.2c02751","article-title":"Performance\nEvaluation of CO2 Soaking and Flooding Processes in Tight Oil Reservoirs","volume":"36","author":"Qian","year":"2022","journal-title":"Energy Fuels"},{"key":"2026090809111567100_cit11","doi-asserted-by":"publisher","DOI":"10.1016\/j.fuel.2022.127000","article-title":"The influence of CO2 huff-n-puff\nin tight oil reservoirs on pore structure characteristics and oil\nproduction from the microscopic scale","volume":"335","author":"Huang","year":"2023","journal-title":"Fuel"},{"issue":"17","key":"2026090809111567100_cit12","doi-asserted-by":"publisher","first-page":"12994","DOI":"10.1021\/acs.energyfuels.3c02001","article-title":"Microscopic Production\nCharacteristics of Huff-n-Puff after CO2 Flooding in Tight Oil Sandstone\nReservoirs","volume":"37","author":"Xue","year":"2023","journal-title":"Energy Fuels"},{"key":"2026090809111567100_cit13","doi-asserted-by":"publisher","DOI":"10.1016\/j.petrol.2022.110371","article-title":"The pore-scale mechanisms of surfactant-assisted\nspontaneous and forced imbibition in water-wet tight oil reservoirs","volume":"213","author":"Cao","year":"2022","journal-title":"J. Petrol. Sci. Eng."},{"issue":"3","key":"2026090809111567100_cit14","doi-asserted-by":"publisher","first-page":"185","DOI":"10.46690\/ager.2023.09.06","article-title":"Spontaneous imbibition\nbehavior in porous media with various hydraulic fracture propagations:\nA pore-scale perspective","volume":"9","author":"Zhou","year":"2023","journal-title":"Adv. Geo-Energy Res."},{"key":"2026090809111567100_cit15","doi-asserted-by":"publisher","first-page":"573","DOI":"10.1016\/j.ijmst.2023.02.005","article-title":"Pore-scale modeling of pore structure properties\nand wettability effect on permeability of low-rank coal","volume":"33","author":"Qin","year":"2023","journal-title":"Int. J. Min. Technol."},{"issue":"6","key":"2026090809111567100_cit16","first-page":"1","article-title":"Characteristics and CO2 flooding enhanced oil\nrecovery experiments of Chang 6 in Ordos Basin","volume":"31","author":"Jin","year":"2024","journal-title":"Pet. Geol. Recovery Effic."},{"issue":"2","key":"2026090809111567100_cit17","doi-asserted-by":"publisher","first-page":"41","DOI":"10.46690\/capi.2024.08.02","article-title":"Experimental study on production characteristics and enhanced oil\nrecovery during imbibition and huff-n-puff injection in shale reservoir","volume":"12","author":"Wei","year":"2024","journal-title":"Capillarity"},{"issue":"1","key":"2026090809111567100_cit18","first-page":"188","article-title":"Progress and development\ntrend of water huff-n-puff technology for horizontal wells in tight\noil reservoirs in China","volume":"44","author":"Pu","year":"2023","journal-title":"Acta Petrol. Sin."},{"key":"2026090809111567100_cit19","unstructured":"Shan, J.; Liu, S.; Cui, G.; Liu, Y.; Chi, R.\n          Influencing factors of fracturing\nfluid imbibition\nefficiency based on full pore-size characterization of tight sandstone\nreservoir pore structure\n          Pet. Geol. Oilfield\nDev. Daqing."},{"key":"2026090809111567100_cit20","doi-asserted-by":"publisher","DOI":"10.1016\/j.marpetgeo.2020.104439","article-title":"Insights into the pore\nstructure and implications for fluid flow capacity of tight gas sandstone:\nA case study in the Upper Paleozoic of the Ordos Basin","volume":"118","author":"Qiao","year":"2020","journal-title":"Mar. Pet. Geol."},{"issue":"3","key":"2026090809111567100_cit21","first-page":"20","article-title":"Pore structure\nand fractal characteristics of ultra-low permeability\nreservoirs in Yanchang Formation in Zhenbei area, Ordos Basin","volume":"27","author":"Zhang","year":"2020","journal-title":"Pet. Geol. Recovery Effic."},{"issue":"6","key":"2026090809111567100_cit22","first-page":"29","article-title":"Hybrid sediments characteristics and sedimentary\nevolution of Upper Carbon\u2013iferous Benxi Formation in Qingjian-Yichuan\narea of Ordos Basin","volume":"43","author":"Cao","year":"2024","journal-title":"Pet. Geol. Oilfield Dev.\nDaqing"},{"issue":"1","key":"2026090809111567100_cit23","first-page":"214","article-title":"Heterogeneity characteristics and\nits constraints on accumulation of tight sandstone reservoirs in the\nsouthwestern Sulige gasfield, Ordosbasin","volume":"98","author":"Cui","year":"2024","journal-title":"Acta\nChim. Sin."},{"issue":"34","key":"2026090809111567100_cit24","first-page":"52","article-title":"Microscopic characteristics and main controlling factors of tight\noil reservoir of yanchang formation in southeastern Ordos Basin, China","volume":"16","author":"Zhang","year":"2016","journal-title":"Sci. Technol. Eng."},{"issue":"2","key":"2026090809111567100_cit25","first-page":"33","article-title":"Characteristics of\nSedimentary Microfacies of Chang 6 Member North Wuqi Area and Its\nEffect on Reservoir Heterogeneity","volume":"38","author":"Zhao","year":"2023","journal-title":"J. Xian Shiyou\nUniv."},{"issue":"4","key":"2026090809111567100_cit26","first-page":"29","article-title":"Heterogeneity Characteristics\nof deep tight sandstone reservoir and its controlling factors: a case\nstudy of Jurassic Qigu Formation in Yongjin area, Junggar Basin","volume":"48","author":"Tian","year":"2024","journal-title":"J. Northeast Pet. Univ."},{"key":"2026090809111567100_cit27","doi-asserted-by":"publisher","first-page":"1461","DOI":"10.1016\/j.jngse.2016.01.002","article-title":"The effect of microstructure and rock mineralogy\non water imbibition characteristics in tight reservoirs","volume":"34","author":"Yang","year":"2016","journal-title":"J. Nat. Gas. Sci. 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Dev."},{"key":"2026090809111567100_cit31","doi-asserted-by":"publisher","first-page":"643","DOI":"10.2118\/209415-PA","article-title":"A Molecular\nDynamics Study on Low-Pressure\nCarbon Dioxide in the Water\/Oil Interface for Enhanced Oil Recovery","volume":"28","author":"Chang","year":"2023","journal-title":"SPE J."},{"key":"2026090809111567100_cit32","doi-asserted-by":"publisher","DOI":"10.3390\/molecules29051112","article-title":"Study on the Effects of Wettability and Pressure in Shale Matrix\nNanopore Imbibition during Shut-in Process by Molecular Dynamics Simulations","volume":"29","author":"Jiang","year":"2024","journal-title":"Molecules"},{"issue":"2","key":"2026090809111567100_cit33","first-page":"244","article-title":"Effect Evaluation\nand Process Parameter Optimization of Synergistic Pressure Flooding\nin Low Permeability Reservoir of Bohai B Oilfield","volume":"42","author":"Liu","year":"2025","journal-title":"Oilfield Chem."},{"key":"2026090809111567100_cit34","doi-asserted-by":"publisher","DOI":"10.1016\/j.geoen.2024.213202","article-title":"Nanopores-to-microfractures\nflow mechanism and remaining distribution of shale oil during dynamic\nwater spontaneous imbibition studied by NMR","volume":"241","author":"Lin","year":"2024","journal-title":"Geoenergy Sci. Eng."},{"issue":"11","key":"2026090809111567100_cit35","first-page":"1157","article-title":"Effects\nof surfactants on imbibition in low\npermeability reservoirs","volume":"48","author":"Wang","year":"2019","journal-title":"Petrochem. Technol."},{"key":"2026090809111567100_cit36","doi-asserted-by":"publisher","DOI":"10.1016\/j.geoen.2022.211403","article-title":"Nuclear magnetic resonance pore radius transformation\nmethod and fluid mobility characterization of shale oil reservoirs","volume":"221","author":"Li","year":"2023","journal-title":"Geoenergy Sci. 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Eng."},{"issue":"1","key":"2026090809111567100_cit41","doi-asserted-by":"publisher","DOI":"10.1016\/j.molliq.2023.122791","article-title":"Experimental\nand numerical simulation research\non counter-current imbibition distance in tight oil reservoirs","volume":"389","author":"Zhang","year":"2023","journal-title":"J. Mol. Liq."},{"issue":"4","key":"2026090809111567100_cit42","doi-asserted-by":"publisher","first-page":"779","DOI":"10.1016\/S1876-3804(19)60235-1","article-title":"Analysis on the influencing factors of imbibition\nand the effect evaluation of imbibition in tight reservoirs","volume":"46","author":"Yang","year":"2019","journal-title":"Pet. Exp. Dev."},{"key":"2026090809111567100_cit43","doi-asserted-by":"publisher","DOI":"10.3390\/pr13020503","article-title":"Experimental\nInvestigation of Factors Influencing Spontaneous Imbibition in Shale\nReservoirs","volume":"13","author":"Liu","year":"2025","journal-title":"Processes"},{"key":"2026090809111567100_cit44","doi-asserted-by":"crossref","DOI":"10.2118\/22594-MS","article-title":"Capillary\nimbibition and gravity segregation\nin low IFT systems","author":"Schechter","year":"1991"},{"issue":"32","key":"2026090809111567100_cit45","first-page":"338","article-title":"Performance evaluation and oil displacement\nmechanism analysis of nanomicroemulsion using in tight oil reservoir","volume":"39","author":"Zhao","year":"2022","journal-title":"Oilfield Chem."},{"key":"2026090809111567100_cit46","doi-asserted-by":"publisher","DOI":"10.3390\/en17092010","article-title":"Hartmann\u2013Sprenger\nEnergy Separation Effect for the Quasi-Isothermal Pressure Reduction\nof Natural Gas: Feasibility Analysis and Numerical Simulation","volume":"17","author":"Belousov","year":"2024","journal-title":"Energies"},{"key":"2026090809111567100_cit47","doi-asserted-by":"publisher","DOI":"10.1016\/j.geoen.2024.213057","article-title":"An efficient method\nfor imbibition in asphaltene-adsorbed tight oil-wet reservoirs","volume":"240","author":"Yan","year":"2024","journal-title":"Geoenergy Sci. Eng."},{"issue":"6","key":"2026090809111567100_cit48","doi-asserted-by":"publisher","first-page":"1259","DOI":"10.1016\/S1876-3804(24)60478-7","article-title":"Optimization of shut-in time based\non saturation rebalancing\nin volume-fractured tight oil reservoirs","volume":"50","author":"Xu","year":"2023","journal-title":"Pet.\nExp. Dev."},{"issue":"3","key":"2026090809111567100_cit49","doi-asserted-by":"publisher","first-page":"509","DOI":"10.32604\/fdmp.2025.060393","article-title":"Water Huff-n-Puff Optimization in\nHigh Saturation Tight Oil Reservoirs","volume":"21","author":"Zhang","year":"2025","journal-title":"Fluid\nDyn. Mater. Proc."},{"issue":"5","key":"2026090809111567100_cit50","first-page":"727","article-title":"Huff-n-puff\ntechnology\nand parameter optimization of large displacement water injection in\ntight oil reservoir","volume":"14","author":"Zhang","year":"2024","journal-title":"Pet. Reservoir Eval. Dev."}],"container-title":["ACS Omega"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pubs.acs.org\/doi\/pdf\/10.1021\/acsomega.6c03053","content-type":"application\/pdf","content-version":"vor","intended-application":"unspecified"},{"URL":"https:\/\/pubs.acs.org\/acsodf\/article-pdf\/11\/35\/52200\/67023840\/acsomega.6c03053.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/pubs.acs.org\/acsodf\/article-pdf\/11\/35\/52200\/67023840\/acsomega.6c03053.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,8]],"date-time":"2026-09-08T13:11:27Z","timestamp":1788873087000},"score":1,"resource":{"primary":{"URL":"https:\/\/pubs.acs.org\/acsodf\/article\/11\/35\/52200\/5289400\/Enhancement-Mechanisms-of-Multi-Scale-Huff-and"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,8,21]]},"references-count":50,"journal-issue":{"issue":"35","published-online":{"date-parts":[[2026,8,21]]},"published-print":{"date-parts":[[2026,9,8]]}},"URL":"https:\/\/doi.org\/10.1021\/acsomega.6c03053","relation":{},"ISSN":["2470-1343"],"issn-type":[{"value":"2470-1343","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,8,21]]}}}