西南石油大学学报(自然科学版)

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Study on the Mechanism of Chlorine Coagulant in Heavy Oil Thermal Wells Cementing

Li Zaoyuan, Luo Jie, Wang Yan, Cheng Xiaowei, Guo Xiaoyang   

  1. State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation,Southwest Petroleum University,Chengdu,Sichuan 610500,China
  • Online:2014-08-01 Published:2014-08-01

Abstract:

The chlorine coagulant has been used in thermal recovery cementation. Few in-depth researches have been made on the effects and the mechanism of oil well cementing performance under the high temperature condition. In this paper,the effects of different types and dosage of coagulant on the compressive strength of silica sand cement are evaluated,and the effects of chlorine coagulant on the compressive strength of silica sand cement is studied in detail;the structure of hydrate component and microstructure before and after high temperature are measured by means of XRD and SEM,and the functional mechanism of chlorine coagulant on the structural change of silica sand cement is discussed. The results shows that the hydration products Xonotlite is the main reason for the non-decline of the compressive strength of cement after high temperature. When the temperature exceeds 230℃,the component of hydration products of cement is affected by the chloride ions,generating a new inclined long calcium stone component,and changing the microstructure of cement,which is the main reason for the sharp decline of the compressive strength.

Key words: heavy oil thermal recovery well, G cement with silica sand, chlorine coagulant, compressive strength, decline
mechanism