Petroleum Science >2011, Issue 3: 328-334 DOI: https://doi.org/10.1007/s12182-011-0149-6
Mechanism and performance of a lithium chloride accelerator Open Access
文章信息
作者：Wang Chengwen,Wang Ruihe,Cheng Rongchao and Chen Erding
作者单位：
School of Petroleum Engineering, China University of Petroleum, Qingdao, Shandong 266555, China;School of Petroleum Engineering, China University of Petroleum, Qingdao, Shandong 266555, China;Department of Drilling Strategy and Planning, CNPC Drilling Research Institute, Beijing 100195, China;Drilling Engineering and Technology Corp., Shengli Petroleum Administration Bureau, Dongying, Shandong 257064, China
投稿时间：2010-10-02
引用方式：Wang, C., Wang, R., Cheng, R. et al. Pet. Sci. (2011) 8: 328. https://doi.org/10.1007/s12182-011-0149-6
文章摘要
To address present concerns about thickening time and high early-strength in deepwater
cementing at low temperatures when using conventional accelerators, a new type of set-accelerating admixture comprising of lithium chloride, aluminium hydroxide and alkaline metal chlorides, named as LS-A, was studied in this paper. Mechanism analysis and performance tests show that the accelerator LS-A accelerated the hydration of tri- and dicalcium silicates (C3S and C2S) at low-temperatures by speeding up the breakdown of the protective hydration film and shortening the hydration induction period. Therefore, LS-A could shorten the low-temperature thickening time and the transition time of critical gel strength from 48 to 240 Pa of the Class-G cement slurry, and improve the early compressive strength of set cement at low-temperatures. It exhibited better performance than calcium chloride and had no effect on the type of hydration products, which remain the same as those of neat Class-G cement, i.e. the calcium silicate gel, Ca(OH) 2 crystals and a small amount of ettringite Aft crystals. LS-A provides an effective way to guarantee the safety of cementing operations, and to solve the problems of low temperature and shallow water/gas fl owing faced in deepwater cementing.
cementing at low temperatures when using conventional accelerators, a new type of set-accelerating admixture comprising of lithium chloride, aluminium hydroxide and alkaline metal chlorides, named as LS-A, was studied in this paper. Mechanism analysis and performance tests show that the accelerator LS-A accelerated the hydration of tri- and dicalcium silicates (C3S and C2S) at low-temperatures by speeding up the breakdown of the protective hydration film and shortening the hydration induction period. Therefore, LS-A could shorten the low-temperature thickening time and the transition time of critical gel strength from 48 to 240 Pa of the Class-G cement slurry, and improve the early compressive strength of set cement at low-temperatures. It exhibited better performance than calcium chloride and had no effect on the type of hydration products, which remain the same as those of neat Class-G cement, i.e. the calcium silicate gel, Ca(OH) 2 crystals and a small amount of ettringite Aft crystals. LS-A provides an effective way to guarantee the safety of cementing operations, and to solve the problems of low temperature and shallow water/gas fl owing faced in deepwater cementing.
关键词
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Deepwater cementing, accelerator, lithium chloride, Class-G cement, mechanism