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Investigation of rock salt layer creep and its effects on casing collapse

Taheri, S. R ; Sharif University of Technology | 2020

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  1. Type of Document: Article
  2. DOI: 10.1016/j.ijmst.2020.02.001
  3. Publisher: China University of Mining and Technology , 2020
  4. Abstract:
  5. Casing collapse is one of the costly incidents in the oil industry. In the oil fields of southwest Iran, most casing collapses have occurred in Gachsaran formation, and the halite rock salt layer in this formation may be the main cause for these incidents because of its peculiar creep behavior. In this research, triaxial creep experiments have been conducted on Gachsaran salt samples under various temperatures and differential stresses. The main purpose was to determine the creep characteristics of Gachsaran rock salt, and to examine the role of creep in several casing collapses that occurred in this formation. Results indicated that the halite rock salt of Gachsaran formation basically obeys the power law; however, its creep parameters are quite different from other halite rocks elsewhere. The time-dependent creep of Gachsaran rock salt exhibits strong sensitivity to temperature change; however, its sensitivity to variation of differential stress is rather low. The numerical simulation of the rock salt creep in a real oil well demonstrated the importance of creep and reservoir conditions on the safety factor of the tubing related to casing collapse. © 2020
  6. Keywords:
  7. Casing collapse ; Creep ; Gachsaran formation ; Numerical simulation ; Power law ; Rock salt ; Chloride minerals ; Computer simulation ; Numerical models ; Oil well casings ; Oil wells ; Rocks ; Safety factor ; Salt deposits ; Sensitivity analysis ; Sodium chloride ; Creep characteristics ; Gachsaran ; Power-law ; Sensitivity to temperatures ; Sensitivity to variations ; Triaxial creep experiments
  8. Source: International Journal of Mining Science and Technology ; Volume 30, Issue 3 , 2020 , Pages 357-365
  9. URL: https://www.sciencedirect.com/science/article/pii/S2095268618306463#!