{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,23]],"date-time":"2026-03-23T20:02:21Z","timestamp":1774296141229,"version":"3.50.1"},"reference-count":39,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2025,10,30]],"date-time":"2025-10-30T00:00:00Z","timestamp":1761782400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Sinopec Northwest Oilfield Company, Xinjiang Urumqi","award":["KJ202336"],"award-info":[{"award-number":["KJ202336"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Gels"],"abstract":"<jats:p>Profile control is widely employed to improve oil recovery in fractured-vuggy carbonate reservoirs. However, the limitation of current experimental evaluation methods restricts their practical guidance for field applications. In this study, urea-formaldehyde resin gel (URG) is studied using SEM, rheological analysis, FTIR, and Raman spectroscopy. Typical structural models of fractured-vuggy reservoirs are fabricated by 3D printing technology. The distribution patterns of the URG in different fractured-vuggy models are also investigated by using online NMR analysis and core slice characterization. Results show that URG exhibits a kind of 3D mesh structure with a size of 10 \u03bcm after gelation at 140 \u00b0C. The storage modulus (G\u2032) and loss modulus (G\u2033) of the URG gel are 387.51 Pa and 131.48 Pa, respectively. Chemical composition analysis reveals that URG is mainly composed of amide groups and sulfonate groups, showing excellent thermal stability and salt tolerance. Furthermore, after injecting URG into three types of typical models, URG displays a longitudinally decreasing distribution pattern from the injection side to the outlet side, accompanied by transverse accumulation phenomenon along the fracture walls in the slab fracture model. In the fractured-vuggy model, the gel shows continuous longitudinal distribution and uniform transverse distribution characteristics. In the beaded-vug train model, the gel\u2019s distribution morphology gradually transforms from a \u201cpipeline-filling\u201d pattern at the injection side to a \u201cconduit-dominant\u201d pattern toward the outlet side, with a stepped distribution in the transverse direction. The breakthrough pressures during subsequent water flooding are as follows: beaded-vug train model (11.6 MPa) &gt; fractured-vuggy model (8.1 MPa) &gt; slab fracture model (5.9 MPa). Field application results show that the water cut is reduced from 85% to 30%, with a total incremental oil production of 2416 tons. This study conducts experimental investigations on the distribution patterns of URG in simulated fractured-vuggy models, thereby establishing a novel technical evaluation method for profile control in actual fractured-vuggy carbonate reservoirs.<\/jats:p>","DOI":"10.3390\/gels11110868","type":"journal-article","created":{"date-parts":[[2025,10,31]],"date-time":"2025-10-31T05:28:43Z","timestamp":1761888523000},"page":"868","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Research on the Distribution Characteristics of Urea-Formaldehyde Resin Gel Influenced by Structural Development in Fractured-Vuggy Reservoirs"],"prefix":"10.3390","volume":"11","author":[{"given":"Zhengcong","family":"Song","sequence":"first","affiliation":[{"name":"Sinopec Northwest Oilfield Company, Urumqi 830014, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Weipeng","family":"Wu","sequence":"additional","affiliation":[{"name":"Sinopec Northwest Oilfield Company, Urumqi 830014, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1771-8011","authenticated-orcid":false,"given":"Ming","family":"Qu","sequence":"additional","affiliation":[{"name":"Sanya Offshore Oil and Gas Research Institute, Northeast Petroleum University, Sanya 572025, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jiaxin","family":"Xi","sequence":"additional","affiliation":[{"name":"Oil and Gas Technology Research Institute of PetroChina Changqing Oilfield Company, Xi\u2019an 710018, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Min","family":"Yang","sequence":"additional","affiliation":[{"name":"Sinopec Northwest Oilfield Company, Urumqi 830014, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xingliang","family":"Jia","sequence":"additional","affiliation":[{"name":"Sinopec Northwest Oilfield Company, Urumqi 830014, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yuheng","family":"Zhao","sequence":"additional","affiliation":[{"name":"Unconventional Petroleum Research Institute, China University of Petroleum, Beijing 102249, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lu","family":"Liu","sequence":"additional","affiliation":[{"name":"Sinopec Northwest Oilfield Company, Urumqi 830014, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Haihua","family":"Cui","sequence":"additional","affiliation":[{"name":"Sinopec Northwest Oilfield Company, Urumqi 830014, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,10,30]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"213643","DOI":"10.1016\/j.geoen.2025.213643","article-title":"Multi-field coupling effects in fractured-vuggy gas storage reservoirs: A high-precision large-scale spatiotemporal numerical simulation","volume":"246","author":"Zhang","year":"2025","journal-title":"Geoenergy Sci. 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