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

International Journal of Mining Science and Technology

Meisam Razifar¹  Ali Pak²  Behzad Mehrgini²  S. Reza Taheri³  Saeed Shad³ 

[1] Corresponding author.;Upstream Petroleum Research Institute, Sharif University of Technology, Tehran, Iran;Civil Engineering Department, Sharif University of Technology, Tehran, Iran;

关键词: Rock salt;    Gachsaran formation;    Creep;    Power law;    Casing collapse;    Numerical simulation;   

DOI  :  

来源: DOAJ

【 摘 要 】

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.

【 授权许可】

Unknown