Proceedings of the Thirty-second (2022) International Ocean and Polar Engineering Conference
Shanghai, China, June 5–10, 2022
Copyright © 2022 by the International Society of Offshore and Polar Engineers (ISOPE)
ISBN 978-1-880653-81-4; ISSN 1098-6189

www.isope.org

The design of well cement slurry with low hydration exothermic for cementing natural gas hydrate
reservoir under deep watera

Huajie Liu a,b, Meihua Huo a,b, Yuhuan BU a,b, Rui Ma a,b

Shandong Key Laboratory of Oilfield Chemistry, Key Laboratory of Unconventional Oil & Gas Development (China University of Petroleum (EastChina)), Ministry of Education.
b
School of Petroleum Engineering, China University of Petroleum (East China).
Qingdao, Shandong Province, China.

ABSTRACTThe hollow microspheres were prepared by inverse suspension
polymerization, which regarded metakaolin as raw material andregarded alkali solution as activator. Metakaolin was provided byYukun Mineral Company, Jiaozuo, China. Sodium hydroxide andsodium silicate were provided by Xilong Science and Technology Co.
Ltd. and Guangzhou Julan Chemical Co. Ltd. PCM-30 (variation rangeof phase transition temperature: 15-40 ℃) is a thermally stable andreliable oily hydrocarbon (No degradation occurring below 100 ℃ andcontinuous melting and freezing cycle shown), which has high phasetransformation latent heat storage capacity (189 J / g). Its latent heatand temperature remain unchanged after multiple endothermic andexothermic processes, and there is no phase separation and corrosivity.
Waterborne bisphenol A epoxy resin (ER) and waterborne polyamine
epoxy curing agent are produced by Shanghai Hanzhong Coatings Co.
Ltd., China. Class G oil well cement (600 mesh) is produced bySichuan Jiahua Special Cement Co. Ltd. The specific surface area ofClass G oil well cement is 332 m2 / kg, and the density of cement
powder is 3.1g/m3. Micro silicon (1000 mesh) was provided by Po Ken
International Trading Company, Shandong province, China, andfloating beads (6000 mesh) from Maanshan Institute of Mining
Research, Anhui province, China. Fluid loss additive (polycarboxylicacids) and dispersant (sulfonated aldehydes and ketones) were provided
by BO-XING engineering science and technology company of CNPC,
Tianjin, China.

Gas hydrate dissociation would damage the cementing quality seriously
due to the hydration exothermic of cement slurry. Therefore, the wellcement slurry with low hydration exothermic is necessary.
The design of well cement slurry with low hydration heat mainly
includes three steps. First, high-strength metakaolin-based hollow-coremicrospheres (HMHM) were prepared. Second, phase change materials(PCM) was applied for encapsulating HMHM to form energy storage
microsphere (ESM). Finally, the hydration heat of well cement withdifferent dosage of ESM were tested, and the strength, rheologicalproperty, sedimentation stability and other basic properties were alsoevaluated.

KEY WORDS: Well cement slurry; low hydration exothermic;
natural gas hydrate reservoir; deep Water; energy storage
microsphere.
INTRODUCTION
Hydrate reservoirs with high pressure and low temperature are
distributed in offshore deep-water areas (Ravi, 1999; Armstrong, 2002).
In the process of deep-water cementing, the temperature around thewellbore increases due to the heat release of cement slurry hydration,
which destroys the stability of natural gas hydrate (Wang, 2019). The
decomposition of natural gas hydrate will seriously damage thecementing quality (Xu, 2005). Paraffin is a phase change materials,
which can effectively reduce the hydration heat release of cement, butparaffin can not be directly added to cement. Therefore, HMHM wereintroduced as new energy storage microspheres to carry PCM to avoid
its directcontact with the cement slurry.

MethodThe preparation of ESM. The steps of forming ESM is as follows.
Firstly, metakaolin, sodium hydroxide, sodium silicate, pore forming
agent (a kind of soluble salt ball) and water were mixed in the ratio of
1:0.12:0.5:0.5:1 to prepare alkali activation metakaolin reaction system.
The alkali activation metakaolin reaction system was stirred anddispersed in the oil phase, which metakaolin was activated by alkali
and solidified rapidly to form microspheres. After HMHM wereprepared by dissolving pore forming agent, HMHM were filtered fromthe oil phase and then sintered in a muffle furnace to obtain highstrength. Then, the hollow microspheres were mixed with PCM-30

EXPERIMENTAL
Materials

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