西南石油大学学报(自然科学版) ›› 2017, Vol. 39 ›› Issue (1): 155-160.DOI: 10.11885/j.issn.1674-5086.2015.06.27.02

Previous Articles     Next Articles

Flushing Fluid for Diesel-based Drilling Fluid Cleaning

GUO Xiaoyang1, OU Hongjuan1,2, LI Ming1, GU Tao1, LIU Honghua1,3   

  1. 1. State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu, Sichuan 610500, China;
    2. Shaanxi China-Consulting Civil Engineering Technology Academy Co. Ltd., Xi'an, Shaanxi 713702, China;
    3. Shaanxi Changxing Petroleum Technology Co, Ltd., Xi'an, Shaanxi 710016, China
  • Received:2015-06-27 Online:2017-02-01 Published:2017-02-01

Abstract: A diesel-based drilling fluid (DBDF) is wildly applied in complex deep wells. However, its strong adhesion to the casing and the well would severely affect the cementing quality. To solve this problem, a study on the preflush system FYJ was conducted: (1) established an optimized method of a surfactant; (2) optimized the efficient surfactants; (3) evaluated indexes referring to the fluid flushing efficiency, the properties of wetting reverse, and compatibility with drilling mud, and we obtained a flushing fluid FYJ having a good comprehensive property. The results showed that (1) Anionic/non-ionic or mixed surfactants with HLB values of 12-15 should be used in preflush systems, the minimum surface tension of the surfactant solution ((γmin) should be close to or less than that of soaking surfaces of DBDF (γc≈23-27 mN/m), and the optimum addition amount of the surfactant should be greater than the critical micelle concentration (CMC value). (2) The preflush system FYJ can remove 82% of the DBDF attached to the well and casing walls, which have a strong temperature and salt resistance. (3) The preflush system FYJ provides good compatibility with DBDF and slurry, and it can effectively dilute the DBDF and slurry.

Key words: diesel-based drilling fluid, surfactant, flushing fluid, cleaning efficiency, wettability reversal, compatibility

CLC Number: