{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,29]],"date-time":"2026-10-29T01:34:47Z","timestamp":1793237687029,"version":"4.5.0"},"reference-count":43,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2025,2,23]],"date-time":"2025-02-23T00:00:00Z","timestamp":1740268800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Polymers"],"abstract":"<jats:p>To address the challenges of micro-fracture development in shale formations, frequent wellbore instability, and the limited plugging capability of water-based drilling fluids in unconventional reservoirs, a nano-plugging agent (NPA) was synthesized using emulsion polymerization. The synthesized NPA was characterized through thermogravimetric analysis (TGA) and transmission electron microscopy (TEM), revealing excellent high-temperature stability and a spherical or sub-spherical morphology, with particle diameters ranging from approximately 20 to 50 nm. The rheological, filtration, and plugging properties of NPA were systematically evaluated, and its sealing mechanism was analyzed. The results demonstrate that at a test temperature of 180 \u00b0C, the optimal NPA concentration in the drilling fluid base slurry is 1.5%, achieving a 60.5% reduction in HTHP (high-temperature high-pressure) sand disc filtration loss. Additionally, the API filtration loss and HTHP filtration loss reduction rates reached 58.1% and 50.3%, respectively, highlighting the remarkable filtration loss reduction and plugging efficiency of NPA under high-temperature conditions. After NPA treatment, the specific surface area and pore volume of shale cuttings decreased to 9.348 m2\/g and 0.035 cm3\/g, respectively, indicating effective surface plugging. The mechanism analysis suggests that due to its nanoscale size, NPA can penetrate deep into micro-pores and fractures within the shale, achieving deep-layer plugging. Furthermore, NPA forms a physical plugging barrier on the shale surface, effectively suppressing shale hydration and swelling. This study provides valuable insights and guidance for addressing wellbore instability and the insufficient plugging performance of drilling fluids in unconventional reservoir drilling operations.<\/jats:p>","DOI":"10.3390\/polym17050588","type":"journal-article","created":{"date-parts":[[2025,2,24]],"date-time":"2025-02-24T10:52:47Z","timestamp":1740394367000},"page":"588","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":12,"title":["Preparation and Performance Evaluation of High-Temperature Polymer Nano-Plugging Agents for Water-Based Drilling Fluids Systems Applicable to Unconventional Reservoirs"],"prefix":"10.3390","volume":"17","author":[{"given":"Lei","family":"Yao","sequence":"first","affiliation":[{"name":"China Oilfield Services Ltd., Tianjin 300451, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xiaohu","family":"Quan","sequence":"additional","affiliation":[{"name":"Oil and Gas Resources Research Center, Ningxia University, Yinchuan 750021, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yongjie","family":"Zhang","sequence":"additional","affiliation":[{"name":"China Oilfield Services Ltd., Tianjin 300451, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3658-7221","authenticated-orcid":false,"given":"Shengming","family":"Huang","sequence":"additional","affiliation":[{"name":"Ministry of Education (MOE) Key Laboratory of Petroleum Engineering, College of Petroleum Engineering, China University of Petroleum (Beijing), Beijing 102249, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Qi","family":"Feng","sequence":"additional","affiliation":[{"name":"Ministry of Education (MOE) Key Laboratory of Petroleum Engineering, College of Petroleum Engineering, China University of Petroleum (Beijing), Beijing 102249, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Xin","family":"Zhang","sequence":"additional","affiliation":[{"name":"Ministry of Education (MOE) Key Laboratory of Petroleum Engineering, College of Petroleum Engineering, China University of Petroleum (Beijing), Beijing 102249, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,2,23]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"354","DOI":"10.1007\/s12182-012-0219-4","article-title":"High temperature and high pressure rheological properties of high-density water-based drilling fluids for deep wells","volume":"9","author":"Wang","year":"2012","journal-title":"Pet. Sci."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"You, F., Zheng, Y., and Gong, X. (2024). Filtration control properties of four native starches in water-based drilling fluids. Int. J. Biol. Macromol., 283.","DOI":"10.1016\/j.ijbiomac.2024.137580"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"110712","DOI":"10.1016\/j.petrol.2022.110712","article-title":"A review of synthetic polymers as filtration control additives for water-based drilling fluids for high-temperature applications","volume":"215","author":"Balaga","year":"2022","journal-title":"J. Pet. Sci. Eng."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"212628","DOI":"10.1016\/j.geoen.2023.212628","article-title":"Compatibility and efficiency of hydrophilic\/hydrophobic nano silica as rheological modifiers and fluid loss reducers in water-based drilling fluids","volume":"234","author":"Li","year":"2024","journal-title":"Geoenergy Sci. Eng."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"106424","DOI":"10.1016\/j.petrol.2019.106424","article-title":"Insights into the application of new eco-friendly drilling fluid additive to improve the fluid properties in water-based drilling fluid systems","volume":"183","author":"Alkinani","year":"2019","journal-title":"J. Pet. Sci. Eng."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"115221","DOI":"10.1016\/j.molliq.2020.115221","article-title":"Preparation, characterization and filtration control properties of crosslinked starch nanospheres in water-based drilling fluids","volume":"325","author":"Zhong","year":"2021","journal-title":"J. Mol. Liq."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"284","DOI":"10.1016\/j.colsurfa.2019.01.055","article-title":"Synthesis of a novel environment-friendly filtration reducer and its application in water-based drilling fluids","volume":"568","author":"Chang","year":"2019","journal-title":"Colloids Surf. A Physicochem. Eng. Asp."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"140430","DOI":"10.1016\/j.jclepro.2023.140430","article-title":"Modified-starch applications as fluid-loss reducers in water-based drilling fluids: A review of recent advances","volume":"434","author":"Davoodi","year":"2014","journal-title":"J. Clean. Prod."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"484","DOI":"10.1016\/j.petrol.2018.07.065","article-title":"Synthesis and characterization of lignosulfonate\/acrylamide graft copolymers and their application in environmentally friendly water- based drilling fluid","volume":"171","author":"Abdollahi","year":"2018","journal-title":"J. Pet. Sci. Eng."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"110021","DOI":"10.1016\/j.petrol.2021.110021","article-title":"Biopolymeric formulations for filtrate control applications in water-based drilling muds: A review","volume":"210","author":"Ali","year":"2022","journal-title":"J. Pet. Sci. Eng."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"123","DOI":"10.1016\/j.petrol.2004.03.008","article-title":"Rheological study of a water-based oil well drilling fluid","volume":"45","author":"Mahto","year":"2004","journal-title":"J. Pet. Sci. Eng."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"96","DOI":"10.1016\/j.clay.2016.11.015","article-title":"Influence of an ionic liquid on rheological and filtration properties of water-based drilling fluids at high temperatures","volume":"136","author":"Luo","year":"2017","journal-title":"Appl. Clay. Sci."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"338","DOI":"10.1016\/j.petrol.2015.01.012","article-title":"Fluid filtration and rheological properties of nanoparticle additive and intercalated clay hybrid bentonite drilling fluids","volume":"127","author":"Barry","year":"2015","journal-title":"J. Pet. Sci. Eng."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"222","DOI":"10.1021\/am2012799","article-title":"Graphene Oxide as a High-Performance Fluid-Loss-Control Additive in Water-Based Drilling Fluids","volume":"4","author":"Kosynkin","year":"2021","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"127478","DOI":"10.1016\/j.colsurfa.2021.127478","article-title":"Synthesis and characterization of thermo-responsive polymer based on carboxymethyl chitosan and its potential application in water-based drilling fluid","volume":"629","author":"Lei","year":"2021","journal-title":"Colloids Surf. A Physicochem. Eng. Asp."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"1028","DOI":"10.1016\/j.petrol.2019.01.002","article-title":"Water-based drilling fluids for high-temperature applications and water-sensitive and dispersible shale formations","volume":"175","author":"Akpan","year":"2019","journal-title":"J. Pet. Sci. Eng."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"116833","DOI":"10.1016\/j.carbpol.2020.116833","article-title":"Insight into \u03b2-cyclodextrin polymer microsphere as a potential filtration reducer in water-based drilling fluids for high temperature application","volume":"249","author":"Zhong","year":"2020","journal-title":"Carbohyd. Polym."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"11963","DOI":"10.1021\/acs.energyfuels.7b02354","article-title":"Novel Acrylamide\/2-Acrylamide-2-methylpropanesulfonic Acid\/4-Vinylpyridine Terpolymer as an Anti-calcium Contamination Fluid-Loss Additive for Water-Based Drilling Fluids","volume":"31","author":"Cao","year":"2017","journal-title":"Energy Fuels"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"118725","DOI":"10.1016\/j.molliq.2022.118725","article-title":"Nanoparticle applications as beneficial oil and gas drilling fluid additives: A review","volume":"352","author":"Davoodi","year":"2022","journal-title":"J. Mol. Liq."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"61","DOI":"10.1016\/j.petrol.2017.11.067","article-title":"Effect of nanoparticles on the modifications of drilling fluids properties: A review of recent advances","volume":"161","author":"Rafati","year":"2018","journal-title":"J. Pet. Sci. Eng."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"76","DOI":"10.1016\/j.clay.2013.10.017","article-title":"Clay nanoparticles modified drilling fluids for drilling of deep hydrocarbon wells","volume":"86","author":"Abdo","year":"2013","journal-title":"Appl. Clay. Sci."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"108","DOI":"10.1016\/j.ijthermalsci.2013.10.016","article-title":"Rheology of mineral oil-SiO2 nanofluids at high pressure and high temperatures","volume":"77","author":"Anoop","year":"2014","journal-title":"Int. J. Therm. Sci."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"42698","DOI":"10.1021\/acsomega.4c00501","article-title":"Research and Evaluation of a Nanometer Plugging Agent for Shale Gas Horizontal Wells","volume":"9","author":"Tian","year":"2024","journal-title":"ACS Omega"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"134676","DOI":"10.1016\/j.colsurfa.2024.134676","article-title":"Study on the preparation and mechanism of two-dimensional nanomaterials as plugging agents for oil-based drilling fluids","volume":"702","author":"Bai","year":"2024","journal-title":"Colloids Surf. A Physicochem. Eng. Asp."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"7733","DOI":"10.1021\/acs.energyfuels.3c04295","article-title":"Temperature-Responsive Nano-SiO2 Composite for Improving Shale Stability in Oil-Based Drilling Fluids","volume":"38","author":"Fan","year":"2024","journal-title":"Energy Fuels"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"21902","DOI":"10.1021\/acsanm.4c03906","article-title":"Experiment and Simulation of Nanoparticles from the Assembly of Poly(St-(1-Octene)-EGDMA) as a Nano-Plugging Agent in Water-Based Drilling Fluids","volume":"7","author":"Xie","year":"2024","journal-title":"ACS Appl. Nano Mater."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"213223","DOI":"10.1016\/j.geoen.2024.213223","article-title":"Investigation on the plugging mechanism of nanocomposite polyacrylate copolymers in water-based drilling fluids: Experiments and applications","volume":"242","author":"Xie","year":"2024","journal-title":"Geoenergy Sci. Eng."},{"key":"ref_28","doi-asserted-by":"crossref","unstructured":"Liu, K., Wang, R., Rong, K., Yin, Z., Liu, T., Yu, Y., Li, Y., Yang, Z., Yang, J., and Zhao, Z. (2023). Synthesis and Plugging Performance of Nano-Micron Polymeric Gel Microsphere Plugging Agents for Oil-Based Drilling Fluids. Gels, 9.","DOI":"10.3390\/gels9040290"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"485704","DOI":"10.1088\/1361-6528\/ac1dd2","article-title":"Dispersive and filter loss performance of calcium carbonate nanoparticles in water for drilling fluid applications","volume":"32","author":"Bai","year":"2021","journal-title":"Nanotechnology"},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"505","DOI":"10.1016\/j.petrol.2015.10.014","article-title":"Synthesis of nano-plugging agent based on AM\/AMPS\/NVP terpolymer","volume":"135","author":"An","year":"2015","journal-title":"J. Pet. Sci. Eng."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"168","DOI":"10.1021\/acs.iecr.6b03450","article-title":"Poly(2-acrylamide-2-methylpropanesulfonic acid)-Modified SiO2 Nanoparticles for Water-Based Muds","volume":"56","author":"Wu","year":"2017","journal-title":"Ind. Eng. Chem. Res."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"880","DOI":"10.1016\/j.petrol.2018.10.064","article-title":"Effect of Nano ZnO on wellbore stability in shale: An experimental investigation","volume":"173","author":"Pourkhalil","year":"2019","journal-title":"J. Pet. Sci. Eng."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"2628","DOI":"10.2118\/209805-PA","article-title":"The Utilization of Self-Crosslinkable Nanoparticles as High-Temperature Plugging Agent in Water- Based Drilling Fluid","volume":"27","author":"Lei","year":"2022","journal-title":"SPE J."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"28304","DOI":"10.1021\/acsomega.2c02784","article-title":"Preparation of the Tetrameric Poly(VS-St-BMA-BA) Nano-Plugging Agent and Its Plugging Mechanism in Water-Based Drilling Fluids","volume":"7","author":"Cheng","year":"2022","journal-title":"ACS Omega"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"128275","DOI":"10.1016\/j.colsurfa.2022.128275","article-title":"Development of a high temperature resistant nano-plugging agent and the plugging performance of multi-scale micropores","volume":"639","author":"Huang","year":"2022","journal-title":"Colloids Surf. A Physicochem. Eng. Asp."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"103082","DOI":"10.1016\/j.jngse.2019.103082","article-title":"Improving the stability of multi-walled carbon nano-tubes in extremely environments: Applications as nano-plugging additives in drilling fluids","volume":"74","author":"Ma","year":"2020","journal-title":"J. Nat. Gas. Sci. Eng."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"5927","DOI":"10.1007\/s10853-018-03239-0","article-title":"Core-shell structure acrylamide copolymer grafted on nano-silica surface as an anti-calcium and anti-temperature fluid loss agent","volume":"54","author":"Ma","year":"2019","journal-title":"J. Mater. Sci."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"418","DOI":"10.1016\/j.jngse.2018.05.023","article-title":"Application of core-shell structural acrylic resin\/nano-SiO2 composite in water based drilling fluid to plug shale pores","volume":"55","author":"Huang","year":"2018","journal-title":"J. Nat. Gas. Sci. Eng."},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Jing, M., Yuan, Z., Li, X., Huang, J., and Tian, Y. (2022). Performance Evaluation and Field Application of Nano Plugging Agent for Shale Water-Based Drilling Fluid. Energies, 15.","DOI":"10.3390\/en15207529"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"123656","DOI":"10.1016\/j.molliq.2023.123656","article-title":"Degradation behavior and mechanism of P(AM\/AA\/AMPS)@PLA core-shell self-degrading temporary plugging agent","volume":"393","author":"Liu","year":"2024","journal-title":"J. Mol. Liq."},{"key":"ref_41","unstructured":"(2014). Petroleum and Natural Gas Industries\u2014Field Testing of Drilling Fluids\u2014Part 1: Water-Based Fluids (Standard No. GB\/T 16783-2014)."},{"key":"ref_42","first-page":"212414","article-title":"Novel polymeric organic gelator as lost circulation material for oil-based drilling fluids","volume":"231","author":"Yang","year":"2023","journal-title":"J. Pet. Sci. Eng."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"310","DOI":"10.1166\/nnl.2017.2293","article-title":"Hyperbranched Polyamine as Nano-Plugging Agent Used in Water-Based Drilling Fluid","volume":"9","author":"Xie","year":"2017","journal-title":"Nanosci. Nanotechnol. Lett."}],"container-title":["Polymers"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2073-4360\/17\/5\/588\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T16:40:44Z","timestamp":1760028044000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2073-4360\/17\/5\/588"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,2,23]]},"references-count":43,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2025,3]]}},"alternative-id":["polym17050588"],"URL":"https:\/\/doi.org\/10.3390\/polym17050588","relation":{},"ISSN":["2073-4360"],"issn-type":[{"value":"2073-4360","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,2,23]]}}}