{
  "abstract": "Bubble-point behavior of shale oil under nanoconfinement is critical for understanding phase evolution during CO2-enhanced shale-oil recovery. In this study, visual micro/nanofluidic PVT experiments were conducted to systematically investigate bubble-point pressure deviations of pentane–CO2, hexadecane–CO2, pentane/decane/hexadecane–CO2, and shale oil–CO2 systems. Measurements were performed at gas–oil ratios of 130 and 260 and temperatures of 65–125 °C using a 10 nm single-scale pore model and a coupled 10 μm–10 nm pore-network model. Experimental results were compared with theoretical predictions from a confinement-modified Peng–Robinson equation of state incorporating capillary pressure, surface adsorption, and critical-property shifts. Furthermore, a metastable nucleation limit was introduced to describe the experimentally observed phase-transition pressure below the equilibrium bubble-point boundary. Pronounced downward deviations toward the metastable region were observed in isolated 10 nm pores. For the pentane–CO2 system at 65 °C and GOR = 130, the experimentally observed phase-transition pressure was approximately 3.5 MPa, compared with an equilibrium prediction of 4.3 MPa, corresponding to a relative deviation of 18.35%. The deviation decreased as temperature approached the critical region and was reduced at higher GOR. For example, at GOR = 260, the deviation of the hexadecane–CO2 system decreased from 40.63% at 65 °C to 10.01% at 125 °C. Fluid composition also strongly affected confinement sensitivity, with heavier hydrocarbon systems exhibiting stronger shifts toward metastable behavior. In contrast, bubble-point pressures in the coupled 10 μm–10 nm network remained close to the equilibrium predictions of the micrometer-scale pores and deviated significantly from the metastable limit. For the shale oil–CO2 system at 65 °C and GOR = 130, the relative deviation decreased from 29.77% in the isolated 10 nm pore model to only 2.43% in the coupled 10 μm–10 nm network. These results demonstrate that nanoconfined bubble-point behavior is governed by the coupled effects of thermodynamic conditions, fluid composition, metastability, and pore-scale connectivity.",
  "abstract_shown": true,
  "affiliations": [
    "Daqing Oilfield of China National Petroleum Cooperation, Daqing 163700, China",
    "State Key Laboratory of Continental Shale Oil, Daqing 163712, China",
    "State Key Laboratory of Deep Oil and Gas, School of Petroleum Engineering, China University of Petroleum (East China), Qingdao 266580, China"
  ],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 9,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Dongyan Qi"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Jiawei Li"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Qiang Liu"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Shuang Wang"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Siyuan Cui"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Yue Lang"
    },
    {
      "affs": [
        2
      ],
      "name": "Jiayi Zhao"
    },
    {
      "affs": [
        2
      ],
      "name": "Xiaozhe Liang"
    },
    {
      "affs": [
        2
      ],
      "name": "Junjie Zhong",
      "orcid": "0000-0001-6293-9580"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/dc3gma3xyd8ac.bib",
  "cited_by": 0,
  "doi": "10.3390/nano16191260",
  "fulltext_url": "https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13667126/?tool=EBI",
  "id": "dc3gma3xyd8ac",
  "issns": [
    "2079-4991"
  ],
  "landing_url": "https://europepmc.org/article/PMC/PMC13667126",
  "language": "eng",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "2212|Enhanced Oil Recovery Techniques"
    ]
  ],
  "openalex": "W7220707653",
  "pdf_url": "https://www.ncbi.nlm.nih.gov/pmc/articles/PMC13667126/pdf/?tool=EBI",
  "pmcid": "PMC13667126",
  "pmid": null,
  "published": "2026-10-01",
  "publisher": "MDPI AG",
  "ris": "https://research.draconitic.com/paper/dc3gma3xyd8ac.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:31Z",
      "native_id": "PMC:PMC13667126",
      "source": "europepmc",
      "url": "https://europepmc.org/article/PMC/PMC13667126"
    },
    {
      "first_seen": "2026-10-30T12:18:45Z",
      "native_id": "10.3390/nano16191260",
      "source": "crossref",
      "url": "https://www.mdpi.com/2079-4991/16/19/1260"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "issn:2079-4991",
      "subfield": "materials-polymers"
    }
  ],
  "title": "Bubble-Point Pressure Deviations and Metastable Nucleation in Nanoconfined CO2–Shale Oil Systems: Effects of Temperature, Composition, Gas–Oil Ratio, and Pore-Scale Coupling",
  "title_text": "Bubble-Point Pressure Deviations and Metastable Nucleation in Nanoconfined CO2–Shale Oil Systems: Effects of Temperature, Composition, Gas–Oil Ratio, and Pore-Scale Coupling",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:18:45Z",
  "url": "https://research.draconitic.com/paper/dc3gma3xyd8ac",
  "venue": "Nanomaterials (Basel, Switzerland)",
  "versions": []
}