天然气水合物多级降压+注化学剂联合开采实验研究

Experimental Study on Combined Production of Natural Gas Hydrate Multi⁃Stage Depressurization and Chemical Injection

宋志康 王雷 黄鑫 许文俊 纪国法

Zhikang Song Lei Wang Xin Huang Wenjun Xu Guofa Ji

长江大学 石油工程学院, 湖北 武汉 430100 油气钻采工程湖北省重点实验室, 湖北 武汉 430100 中国石化石油勘探开发研究院, 北京 122206

School of Petroleum Engineering，Yangtze University，Wuhan Hubei 430100，China Key Laboratory of Drilling and Production Engineering for Oil and Gas，Hubei Province，Wuhan Hubei 430100，China Sinopec Petroleum Exploration and Development Research Institute，Beijing 122206，China

模拟海底高压低温条件合成较高饱和度的天然气水合物，以多级降压模式开采天然气水合物作为空白组，研究了多级降压+注醇类、多级降压+注无机盐类以及不同质量分数化学剂对天然气水合物分解和开采效率的影响。同时，根据实验结果，优选了分解效率最优的化学剂。结果表明，多级降压+注化学剂开采天然气水合物比纯多级降压模式能有效提高瞬时产气速率，且提高整体分解效率；在多级降压+注醇类模式中，多级降压+注30%乙二醇模式性能最佳，与纯多级降压模式相比，其分解效率提高51.3%，2 h内的开采效率提高67.3%；在多级降压+注无机盐类模式中，多级降压+注15%氯化钙模式性能最优，与纯多级降压模式相比，其分解效率提高47.3%，2 h内的开采效率提高60.4%。在实际开采过程中，应选择适宜的化学剂质量分数，以避免污染环境。

The synthesis of gas hydrates with higher saturation under high pressure and low temperature conditions on the seabed was simulated, and use the multi?stage depressurization mode to extract the hydrate as the blank group, and the effects of multi?stage depressurization + alcohol injection, multi?stage depressurization + inorganic salts and chemical agents with different mass concentrations on the decomposition and recovery efficiency of natural gas hydrate were studied. At the same time, according to the experimental results, the chemical agent with the best decomposition efficiency was preferably evaluated. The results show that: the multi?stage depressurization + chemical injection to recover natural gas hydrate can effectively increase the instantaneous gas production rate and improve the overall decomposition efficiency compared with pure depressurization. Among them, the multi?stage depressurization + injection of 30% ethylene glycol has the best performance in alcohols, compared with the pure multi?stage depressurization mode, its decomposition efficiency is increased by 51.3%, and the recovery efficiency within 2 h is increased by 67.3%; the multi?stage depressurization + injection of 15% calcium chloride has the best performance in inorganic salts, compared with the pure multi?stage depressurization mode, its decomposition efficiency is increased by 47.3%, and the recovery efficiency within 2 h is increased by 60.4%. In the actual mining process, the appropriate chemical concentration should be used to avoid environmental pollution.

中国石化科技部项目群课题“天然气水合物有效开采关键技术研究”(P20040?4)

10.3969/j.issn.1672-6952.2022.05.007