{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,13]],"date-time":"2026-10-13T20:45:01Z","timestamp":1791924301259,"version":"4.3.4"},"reference-count":31,"publisher":"American Chemical Society (ACS)","issue":"40","license":[{"start":{"date-parts":[[2026,9,29]],"date-time":"2026-09-29T00:00:00Z","timestamp":1790640000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100005046","name":"Natural Science Foundation of Heilongjiang Province","doi-asserted-by":"publisher","award":["XQ2026E017"],"award-info":[{"award-number":["XQ2026E017"]}],"id":[{"id":"10.13039\/501100005046","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,10,13]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>Water-lock damage in low-permeability sandstone reservoirs is primarily caused by small pore-throat structures, strong capillary forces, and hydrophilic rock surfaces. Conventional treatment methods mainly target either fluid-interface modification or pore blockage problems separately. In this study, a nanoemulsion\/mud acid composite system was developed to achieve a combined effect of fluid interfaces and localized mineral dissolution. Interfacial tension (IFT) measurements, contact angle analysis, constant-rate mercury intrusion (CRMI), nuclear magnetic resonance (NMR), and high-temperature high-pressure core flooding experiments were conducted to investigate the water-lock removal performance and underlying mechanisms of the composite system. The results demonstrate that the optimized 0.20 wt % nanoemulsion\/mud acid system reduced the oil\u2013water interfacial tension to 0.486 \u00d7 10\u20133 (mN\u00b7m\u20131) and increased the contact angle to 116.4\u00b0. The combined CRMI\u2013NMR characterization revealed that fluid mobility in low-permeability sandstone can be classified into bound, transition, and movable zones, rather than being described by a single flow threshold. Increasing the production pressure differential intensified deep water-phase invasion and retention, weakened the production enhancement effect caused by increased driving force, and further aggravated water-lock damage. Mineralogical analysis, NMR measurements, and permeability-recovery experiments collectively indicate that water-lock removal is associated with coupled interfacial regulation and localized pore\u2013throat modification. These findings provide a pore-scale theoretical basis for optimizing treatment-agent concentration and production pressure differential, while further field-scale validation remains necessary.<\/jats:p>","DOI":"10.1021\/acsomega.6c07390","type":"journal-article","created":{"date-parts":[[2026,9,30]],"date-time":"2026-09-30T01:02:04Z","timestamp":1790730124000},"page":"61781-61797","source":"Crossref","is-referenced-by-count":0,"title":["Mechanisms of Water-Lock\nRemoval by a Nanoemulsion\/Mud\nAcid Composite System in Low-Permeability Sandstone Reservoirs: Insights\nfrom Pore-Scale Characterization in the MB Block"],"prefix":"10.1021","volume":"11","author":[{"ORCID":"https:\/\/orcid.org\/0009-0008-3761-3747","authenticated-orcid":true,"given":"Guohui","family":"Qu","sequence":"first","affiliation":[{"name":"Key Laboratory of Enhanced Oil Recovery (Northeast Petroleum University) , , , ,","place":["Daqing, Heilongjiang, China, 163318"]},{"name":"Clausthal University of Technology , ,","place":["Clausthal-Zellerfeld, Germany, 38678"]},{"name":"University of Louisiana at Lafayette , , ,","place":["Lafayette, Louisiana, United States, 70504"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jingxuan","family":"Wu","sequence":"additional","affiliation":[{"name":"Key Laboratory of Enhanced Oil Recovery (Northeast Petroleum University) , , , ,","place":["Daqing, Heilongjiang, China, 163318"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8544-7172","authenticated-orcid":true,"given":"Michael Zhengmeng","family":"Hou","sequence":"additional","affiliation":[{"name":"Clausthal University of Technology , ,","place":["Clausthal-Zellerfeld, Germany, 38678"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yikun","family":"Liu","sequence":"additional","affiliation":[{"name":"Key Laboratory of Enhanced Oil Recovery (Northeast Petroleum University) , , , ,","place":["Daqing, Heilongjiang, China, 163318"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0000-9323-0814","authenticated-orcid":true,"given":"Louis Osei","family":"Twum","sequence":"additional","affiliation":[{"name":"Clausthal University of Technology , ,","place":["Clausthal-Zellerfeld, Germany, 38678"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8424-8975","authenticated-orcid":true,"given":"Ning","family":"Liu","sequence":"additional","affiliation":[{"name":"University of Louisiana at Lafayette , , ,","place":["Lafayette, Louisiana, United States, 70504"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"316","published-online":{"date-parts":[[2026,9,29]]},"reference":[{"key":"2026101315102375400_cit1","doi-asserted-by":"publisher","first-page":"213787","DOI":"10.1016\/j.geoen.2025.213787","article-title":"Effect of Pore-Throat Structure on\nIrreducible Water Saturation and Gas Seepage Capacity in a Multilayer\nTight Sandstone Gas Reservoir","volume":"249","author":"Wang","year":"2025","journal-title":"Geoenergy Sci.\nEng."},{"issue":"2","key":"2026101315102375400_cit2","doi-asserted-by":"publisher","first-page":"1","DOI":"10.3969\/j.issn.2095-4107.2025.02.001","article-title":"Differences\nin Pore-Throat Structure\nand Seepage Characteristics of Tight Sandstone Gas Reservoirs and\nTheir Effects on Water-Blocking: A Case Study of the Shanxi, Taiyuan,\nand Shihezi Formations in the Shenmu Gas Field, Ordos Basin","volume":"49","author":"Qiang","year":"2025","journal-title":"J. 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