深井高温抗二氧化碳腐蚀水泥浆体系设计与优选

Design and select of resisting corrosion cement slurries by carbon dioxide for high temperature deep well

张聪 张景富 乔宏宇 彭邦洲

ZHANG Cong ZHANG Jingfu QIAO Hongyu PENG Bangzhou

东北石油大学提高油气采收率教育部重点实验室，黑龙江大庆　163318

Key Laboratory for Enhanced Oil and Gas Recovery of the Ministry of Education, Daqing Petroleum Institute, Daqing 163318, China

以分析高温条件下CO2腐蚀水泥作用过程为基础，研究了腐蚀条件对腐蚀深度的影响规律，分析了腐蚀深度对水泥石强度降低率的影响特点，对水泥浆体系基本组成进行了优选。结果表明，腐蚀深度随温度、CO2分压、腐蚀时间的增加而增加，分别近似存在对数、线性、平方根的关系，据此建立了腐蚀深度预测模型；不添加抗腐蚀填充材料（RCTM）的水泥浆，腐蚀后水泥石强度降低率随腐蚀深度的增加呈增加趋势，添加RCTM的水泥浆，水泥石抗压强度降低率在腐蚀初期随腐蚀深度增加有上升趋势，腐蚀后期有下降趋势。通过合理设计体系组成，改善水泥石微观结构提高原始强度，能有效提高水泥石抗腐蚀能力。本文设计的6#体系适用于大庆油田120~150 ℃的深井固井。

On the base of analyzing corrosion action process of oilwell cement by carbon dioxide at high temperature, effect law of corrosive conditions on corrosive depth were studied and effect characteristics of corrosive depth on the drop rate of compressive strength were analyzed. The basic composition of cement slurry was selected. The following conclusions are obtained: With the increase of temperature, CO2 deferential pressure and corrosion time, corrosive depth was increased. On the relationship of linear, logarithm and extract the square root between corrosive depth and corrosion time, temperature, CO2 deferential pressure, the corrosive depth prediction model was established. With the increase of corrosive depth, drop rate of compressive strength was increased for cement slurries without Resisting Corrosion Tampon Materials（RCTM）, when the cement slurries were added RCTM, compressive strength drop rate of corrosion cement stone were increased at early curing time, but decreased at later curing time. The resisting ability for cement corrosion by CO2 cloud be enhanced by reasonably designing composition of cement slurry, improving microstructure, increasing original compressive strength. No.6 cement slurry designed by this paper is effective for deep well cementing of temperature 120~150 ℃ to resist cement corrosion by CO2 in Daqing oil field.