{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,29]],"date-time":"2026-09-29T16:07:41Z","timestamp":1790698061545,"version":"4.1.0"},"reference-count":31,"publisher":"American Chemical Society (ACS)","issue":"38","license":[{"start":{"date-parts":[[2026,9,16]],"date-time":"2026-09-16T00:00:00Z","timestamp":1789516800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by-nc-nd\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100018537","name":"National Science and Technology Major Project","doi-asserted-by":"publisher","award":["2025ZD1407300"],"award-info":[{"award-number":["2025ZD1407300"]}],"id":[{"id":"10.13039\/501100018537","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":[],"published-print":{"date-parts":[[2026,9,29]]},"abstract":"<jats:title>Abstract<\/jats:title>\n                  <jats:p>To address the characteristics of strong heterogeneity, complex pore-throat structures, and poor adaptability of conventional flooding systems in conglomerate reservoirs, a systematic comparative study on the oil displacement efficiency of middle-phase microemulsion and conventional binary systems (polymer + surfactant) was conducted using a combination of long-core displacement experiments, interfacial tension measurements, and polarizing microscopy observations. Representative cores with permeability ranging from 50 to 500 mD were selected for displacement experiments under varying conditions of injection rate, permeability contrast, timing of chemical injection, and surfactant concentration. A three-stage experimental procedure comprising waterflooding, chemical flooding, and post-waterflooding was employed to compare and analyze the injectivity, enhanced oil recovery (EOR) magnitude, and water control performance of the two flooding systems. The results indicate that the middle-phase microemulsion exhibits significantly superior oil displacement efficiency compared to the binary system across the entire permeability range. It demonstrates excellent injectivity in medium-permeability reservoirs above 50 mD, rapidly achieving an ultra-low interfacial tension on the order of 10\u20133 mN\/m, which effectively mobilizes residual oil trapped in fine pore throats. The final enhanced oil recovery increment is 3\u20137 percentage points higher than that achieved with the binary system. The applicability boundaries for middle-phase microemulsion flooding are defined as follows: permeability should not be lower than that of conventional low-permeability reservoirs; injection conversion is preferably implemented during the high water-cut stage; the permeability heterogeneity ratio should not exceed 10. Additionally, supporting measures for channeling control are required to accommodate reservoir stress sensitivity. The middle-phase microemulsion effectively inhibits water channeling, and its stability and profile control capability are significantly superior to those of the binary system. The research findings provide technical support and a theoretical basis for enhanced oil recovery in conglomerate reservoirs and analogous highly heterogeneous reservoirs.<\/jats:p>","DOI":"10.1021\/acsomega.6c04634","type":"journal-article","created":{"date-parts":[[2026,9,16]],"date-time":"2026-09-16T12:01:55Z","timestamp":1789560115000},"page":"57106-57116","source":"Crossref","is-referenced-by-count":0,"title":["Experimental Study\non the Mechanism and Effect of\nMiddle-Phase Microemulsion Flooding in a Conglomerate Reservoir"],"prefix":"10.1021","volume":"11","author":[{"given":"Hongzhi","family":"Shao","sequence":"first","affiliation":[{"name":"PetroChina , , ,","place":["Karamay, China, 834000"]},{"name":"PetroChina , , ,","place":["Karamay, China, 834000"]},{"name":"PetroChina , , ,","place":["Karamay, China, 834000"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6763-2203","authenticated-orcid":true,"given":"Tongjing","family":"Liu","sequence":"additional","affiliation":[{"name":"China University of Petroleum-Beijing at Karamay , , , ,","place":["Karamay, Xinjiang, China, 834000"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dan","family":"Guan","sequence":"additional","affiliation":[{"name":"PetroChina , , ,","place":["Karamay, China, 834000"]},{"name":"PetroChina , , ,","place":["Karamay, China, 834000"]},{"name":"PetroChina , , ,","place":["Karamay, China, 834000"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0006-1820-1232","authenticated-orcid":true,"given":"Jiangfei","family":"Sun","sequence":"additional","affiliation":[{"name":"China University of Petroleum-Beijing , , ,","place":["Beijing, China, 102249"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wenjie","family":"Tang","sequence":"additional","affiliation":[{"name":"PetroChina , , ,","place":["Karamay, China, 834000"]},{"name":"PetroChina , , ,","place":["Karamay, China, 834000"]},{"name":"PetroChina , , ,","place":["Karamay, China, 834000"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zirui","family":"Zhao","sequence":"additional","affiliation":[{"name":"China University of Petroleum-Beijing at Karamay , , , ,","place":["Karamay, Xinjiang, China, 834000"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Huoxin","family":"Luan","sequence":"additional","affiliation":[{"name":"PetroChina , , ,","place":["Karamay, China, 834000"]},{"name":"PetroChina , , ,","place":["Karamay, China, 834000"]},{"name":"PetroChina , , ,","place":["Karamay, China, 834000"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Patiguli","family":"Maimaiti","sequence":"additional","affiliation":[{"name":"PetroChina , , ,","place":["Karamay, China, 834000"]},{"name":"PetroChina , , ,","place":["Karamay, China, 834000"]},{"name":"PetroChina , , ,","place":["Karamay, China, 834000"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jiahao","family":"Zhan","sequence":"additional","affiliation":[{"name":"China University of Petroleum-Beijing at Karamay , , , ,","place":["Karamay, Xinjiang, China, 834000"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Baokang","family":"Ren","sequence":"additional","affiliation":[{"name":"China University of Petroleum-Beijing at Karamay , , , ,","place":["Karamay, Xinjiang, China, 834000"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"316","published-online":{"date-parts":[[2026,9,16]]},"reference":[{"issue":"1","key":"2026092911105646000_cit1","first-page":"222","article-title":"Progress and development\ntrend of seismic interpretation technology for large fan delta conglomerate\nreservoirs: taking hydrocarbon exploration in Mahu Sag, Junggar Basin\nas an example","volume":"61","author":"Lin","year":"2026","journal-title":"Oil Geophys. Prospect."},{"key":"2026092911105646000_cit2","first-page":"213","article-title":"Current\nstatus and trends of chemical flooding technology for tertiary oil\nrecovery","volume":"7","author":"Jiang","year":"2023","journal-title":"Chem. Eng. Equip."},{"issue":"7","key":"2026092911105646000_cit3","first-page":"79","article-title":"Application and\nprospect of chemical\nflooding technology in shale oil development","volume":"39","author":"Huang","year":"2025","journal-title":"Chem. Eng."},{"issue":"1","key":"2026092911105646000_cit4","first-page":"87","article-title":"Water-oil seepage characteristics\nof thermochemical flooding in super heavy oil reservoirs","volume":"31","author":"Sun","year":"2024","journal-title":"Spec. Oil Gas Reservoirs"},{"issue":"5","key":"2026092911105646000_cit5","first-page":"1212","article-title":"Laboratory study on\nenhanced oil recovery by microemulsion chemical flooding","volume":"52","author":"Mei","year":"2023","journal-title":"Contemp. Chem. Ind."},{"issue":"3","key":"2026092911105646000_cit6","first-page":"421","article-title":"Experimental study\non oil displacement effect of surfactant-polymer\nbinary composite flooding","volume":"38","author":"Wang","year":"2021","journal-title":"Oilfield Chem."},{"issue":"10","key":"2026092911105646000_cit7","first-page":"55","article-title":"Analysis on chemical\nproperties and EOR of binary composite flooding system","volume":"39","author":"Chen","year":"2025","journal-title":"Chem. Eng."},{"key":"2026092911105646000_cit8","first-page":"40","article-title":"Study on oil displacement contribution of polymer-surfactant\nbinary composite system","volume":"13","author":"Liu","year":"2025","journal-title":"Contemp. Chem. Ind.\nRes."},{"issue":"11","key":"2026092911105646000_cit9","first-page":"2564","article-title":"Experimental study on\nalternating flooding and EOR of binary composite system","volume":"53","author":"Peng","year":"2024","journal-title":"Contemp. Chem. Ind."},{"issue":"5","key":"2026092911105646000_cit10","first-page":"11","article-title":"Study on alkali-free binary composite\nflooding system","volume":"26","author":"Zhao","year":"2025","journal-title":"Adv. Fine Petrochem."},{"issue":"1","key":"2026092911105646000_cit11","first-page":"48","article-title":"Study and application of temperature-resistant\nsalt-tolerant strong emulsifying polymer-surfactant binary flooding\nsystem","volume":"39","author":"Xu","year":"2024","journal-title":"J. Xi\u2019an Shiyou Univ."},{"issue":"5","key":"2026092911105646000_cit12","first-page":"41","article-title":"Mixed sulfonate surfactant\/polymer\nbinary oil displacement system","volume":"31","author":"Chen","year":"2023","journal-title":"Sci. Technol.\nChem. Indus."},{"issue":"5","key":"2026092911105646000_cit13","first-page":"1132","article-title":"Study and application\nof polymer\/surfactant binary flooding system in medium and low permeability\nreservoirs","volume":"54","author":"Gao","year":"2025","journal-title":"Contemp. Chem. Ind."},{"issue":"2","key":"2026092911105646000_cit14","first-page":"81","article-title":"Laboratory study on\nenhanced oil recovery by reactive polymer after polymer flooding","volume":"32","author":"Wu","year":"2025","journal-title":"World Petroleum Indus."},{"key":"2026092911105646000_cit15","first-page":"16","article-title":"Study on\noil displacement effect of strong emulsifying binary system for high\nviscosity crude oil","volume":"2","author":"Wang","year":"2024","journal-title":"Chem. Eng. Equip."},{"issue":"2","key":"2026092911105646000_cit16","first-page":"296","article-title":"Matching relationship\nbetween hydrodynamic size of binary flooding system and reservoir\nthroat size","volume":"41","author":"Wang","year":"2024","journal-title":"Oilfield Chem."},{"issue":"3","key":"2026092911105646000_cit17","first-page":"56","article-title":"Study on optimal middle-phase\nmicroemulsion flooding system","volume":"30","author":"Zhou","year":"2016","journal-title":"Chem. Eng."},{"issue":"11","key":"2026092911105646000_cit18","first-page":"35","article-title":"Study on oil displacement\neffect of middle-phase microemulsion","volume":"29","author":"Zhou","year":"2015","journal-title":"Chem.\nEng."},{"issue":"5","key":"2026092911105646000_cit19","first-page":"1071","article-title":"Effect of NaCl mass fraction on phase behavior and\nsolubilization performance of middle-phase microemulsion","volume":"51","author":"Wang","year":"2022","journal-title":"Contemp. Chem. Ind."},{"issue":"8","key":"2026092911105646000_cit20","first-page":"1175","article-title":"Formation\nof middle-phase\nmicroemulsion and determination methods of characteristic parameters","volume":"41","author":"Zhang","year":"2024","journal-title":"Chin. J. Appl. Chem."},{"issue":"4","key":"2026092911105646000_cit21","first-page":"690","article-title":"In-situ\nformed middle-phase\nmicroemulsion oil displacement system for low permeability reservoirs","volume":"38","author":"Liang","year":"2021","journal-title":"Oilfield Chem."},{"issue":"9","key":"2026092911105646000_cit22","first-page":"2551","article-title":"Screening of middle-phase\nmicroemulsion flooding system for low permeability reservoirs","volume":"52","author":"Wu","year":"2023","journal-title":"Appl. Chem. Ind."},{"issue":"2","key":"2026092911105646000_cit23","first-page":"456","article-title":"Research progress on\noil displacement\nmechanism and application of middle-phase microemulsion","volume":"38","author":"Li","year":"2022","journal-title":"Acta Petrol. Sin."},{"issue":"2","key":"2026092911105646000_cit24","first-page":"233","article-title":"Enhanced oil recovery\nby middle-phase microemulsion of petroleum sulfonate flooding system","volume":"54","author":"Guan","year":"2025","journal-title":"Petrochem. Technol."},{"issue":"5","key":"2026092911105646000_cit25","first-page":"1234","article-title":"Study on influencing factors of middle-phase\nmicroemulsion flooding in heterogeneous cores","volume":"51","author":"Li","year":"2022","journal-title":"Appl. Chem. Ind."},{"issue":"5","key":"2026092911105646000_cit26","first-page":"1234","article-title":"Study on influencing factors of middle-phase\nmicroemulsion flooding in heterogeneous cores","volume":"51","author":"Li","year":"2022","journal-title":"Appl. Chem. Ind."},{"issue":"16","key":"2026092911105646000_cit27","doi-asserted-by":"publisher","first-page":"11955","DOI":"10.1021\/acs.energyfuels.3c01646","article-title":"Interfacial Properties and Efficient Imbibition Mechanism of Anionic\u2013Nonionic\nSurfactants in Shale Porous Media","volume":"37","author":"Liu","year":"2023","journal-title":"Energy Fuels"},{"issue":"20","key":"2026092911105646000_cit28","doi-asserted-by":"crossref","first-page":"19442","DOI":"10.1021\/acs.energyfuels.4c03442","article-title":"Highly\nefficient oil displacement\nperformance of amphiphilic carbon nanosheets with interfacial regulation\nfunction","volume":"38","author":"Xiong","year":"2024","journal-title":"Energy Fuels"},{"issue":"43","key":"2026092911105646000_cit29","first-page":"31663","article-title":"Interfacial activity\nsynergism of ionic liquid-long chain surfactant\ncomposite system for crude oil displacement","volume":"14","author":"Gong","year":"2024","journal-title":"RSC Adv."},{"key":"2026092911105646000_cit30","first-page":"154856","article-title":"Lignin nanoparticle Pickering emulsifiers for ultra-stable oil-water\nmicroemulsion in EOR","volume":"606","author":"Li","year":"2022","journal-title":"Appl. Surf. Sci."},{"key":"2026092911105646000_cit31","first-page":"122631","article-title":"Nanoparticle reinforced microemulsion\nsystem for heavy oil mobilization","volume":"311","author":"Zhang","year":"2022","journal-title":"Fuel"}],"container-title":["ACS Omega"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pubs.acs.org\/doi\/pdf\/10.1021\/acsomega.6c04634","content-type":"application\/pdf","content-version":"vor","intended-application":"unspecified"},{"URL":"https:\/\/pubs.acs.org\/acsodf\/article-pdf\/11\/38\/57106\/68528915\/acsomega.6c04634.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/pubs.acs.org\/acsodf\/article-pdf\/11\/38\/57106\/68528915\/acsomega.6c04634.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,29]],"date-time":"2026-09-29T15:50:25Z","timestamp":1790697025000},"score":1,"resource":{"primary":{"URL":"https:\/\/pubs.acs.org\/acsodf\/article\/11\/38\/57106\/5431106\/Experimental-Study-on-the-Mechanism-and-Effect-of"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,16]]},"references-count":31,"journal-issue":{"issue":"38","published-online":{"date-parts":[[2026,9,16]]},"published-print":{"date-parts":[[2026,9,29]]}},"URL":"https:\/\/doi.org\/10.1021\/acsomega.6c04634","relation":{},"ISSN":["2470-1343"],"issn-type":[{"value":"2470-1343","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,16]]}}}