As one of the most widely used technology to ameliorate the reservoir's heterogeneity, polymer gels have been applied for more than 60 years. However, how to plug fractured reservoirs with significant abnormal features, high temperature and high salinity, especially the divalent cations, is still a challenging target. This work systematically evaluated a novel salt-resistant re-crosslinkable preformed particle gel (SR-RPPG) designed for fractured reservoirs with excellent salt resistance (up to 5 % CaCl2). We evaluated the swelling kinetics, thermal stability and plugging efficiency of this SR-RPPG. We assessed the swelling kinetic and re-crosslinking behavior of the SR-RPPG through the bottle test method. High temperature-resistant glass tubes with thermally stable O-rings were employed to evaluate the long-term thermal stability of the SR-RPPG product, and the testing lasted for over 200 days. A fractured model was used to assess the plugging efficiency of the SR-RPPG product. Results showed that the SR-RPPG could swell more than 30 times its original volume in 5 % CaCl2 and a middle east formation water. Besides, the SR-RPPG gel slurry can re-crosslink to form a rubber-like elastic bulk gel at 80–100 °C, and the elastic modulus of the re-crosslinked bulk gel can reach up to 1350 Pa with a swelling ratio of 10. The SR-RPPG prepared in 1 % NaCl, 2 % KCl, middle east formation water and 5 % CaCl2 with a swelling ratio of 10 have been stable for over 200 days at 100 °C. The core flooding test demonstrated that the SR-RPPG could efficiently block the open fractures, and the water breakthrough pressure gradient reached 927.30 psi/ft (20.98 MPa/m).



Second Department

Geosciences and Geological and Petroleum Engineering


ConocoPhillips, Grant None

Keywords and Phrases

Fractured Reservoirs; Hydrogel; Re-Crosslinkable; Salt-Resistant; Water Management

International Standard Serial Number (ISSN)


Document Type

Article - Journal

Document Version

Final Version

File Type





© 2023 Elsevier, All rights reserved.

Publication Date

01 Jan 2023