工业水处理 ›› 2025, Vol. 45 ›› Issue (5): 166-176. doi: 10.19965/j.cnki.iwt.2024-0364

• 试验研究 • 上一篇    

深层煤层气采出水CO2除钙技术

刘凯文1(), 贾潇2, 李向伟1, 张政3,4, 陈江豪3,4, 谢慧嘉3,4, 李延隆5, 陈武3,4()   

  1. 1. 中石油江汉机械研究所有限公司,湖北 武汉 430074
    2. 中石油长庆油田采气六厂,陕西 西安 710016
    3. 长江大学化学与环境工程学院,湖北 荆州 434023
    4. 中国石油HSE重点实验室(长江大学),湖北 荆州 434023
    5. 中国石油集团渤海石油装备制造有限公司辽河钻采装备分公司,辽宁 盘锦 124010
  • 收稿日期:2024-10-14 出版日期:2025-05-20 发布日期:2025-05-22
  • 通讯作者: 陈武
  • 作者简介:

    刘凯文(1968— ),高级工程师,E-mail:

  • 基金资助:
    中国石油集团油田技术服务有限公司科学研究与技术开发项目(2024T-001-001); 中国石油天然气集团有限公司科学研究与技术开发项目(2021DJ6606)

CO2 calcium removal technology for deep coalbed methane produced water

Kaiwen LIU1(), Xiao JIA2, Xiangwei LI1, Zheng ZHANG3,4, Jianghao CHEN3,4, Huijia XIE3,4, Yanlong LI5, Wu CHEN3,4()   

  1. 1. PetroChina Jianghan Machinery Research Institute Co. , Ltd. , Wuhan 430074, China
    2. PetroChina Changqing Oilfield Gas Production Plant No. 6, Xi’an 710016, China
    3. School of Chemistry and Environmental Engineering, Yangtze University, Jingzhou 434023, China
    4. HSE Key Laboratory of PetroChina (Yangtze University), Jingzhou 434023, China
    5. Liaohe Drilling & Production Equipment Branch, China National Petroleum Group Bohai Petroleum Equipment Manufacturing Co. , Ltd. , Panjin 124010, China
  • Received:2024-10-14 Online:2025-05-20 Published:2025-05-22
  • Contact: Wu CHEN

摘要:

长庆油田某气井的煤层气采出水含有高达10 100 mg/L的Ca2+,严重影响其回用。以CO2作为化学沉淀剂,联合pH调节剂用于采出水除钙。结果表明,采出水初始pH越高,越有利于前期CO2吸收溶解;采出水CO2注入饱和后回调pH越高,释放的CO3 2-越多,除钙效果越好;通气速率与通气时间决定了CO2溶解的速度与数量;温度越高,除钙效果越好;搅拌速率的影响较小;CO2气泡尺寸越小,CO2气体压力越大,越有利于CO2吸收溶解。响应曲面工艺优化结果表明,常温常压下,原水pH=11.0,通气速率为200 mL/min,采用微气泡发生装置通气10 min,回调pH=12.8时,除钙率可达99.21%,处理后的采出水Ca2+质量浓度能够满足回用配制压裂液的要求。CO2除钙不仅是一种既能实现高效除钙、使水资源重复利用,又可实现CO2永久封存与转化的有效技术,还有助于早日实现“碳中和”,是用于处理此类含钙采出水的优秀选择之一。

关键词: 煤层气采出水, 软化除钙, 水处理, CO2

Abstract:

The produced water of coalbed methane from a gas well in Changqing Oilfield contains up to 10 100 mg/L Ca2+, which seriously affects its reuse. CO2 was used as a chemical precipitant in combination with pH regulators for calcium removal from produced water. The results showed that the higher the initial pH of produced water, the more conducive for CO2 absorption and dissolution in early stage. The higher the reverting pH of the produced water after CO2 injection saturation, the more CO3 2- released, and the better the calcium removal effect. The ventilation rate and aeration time determined the speed and amount of CO2 dissolution. The higher the temperature, the better the calcium removal effect. The influence of stirring rate was relatively small in reaction process. The smaller the size of the CO2 bubble and the greater the CO2 gas pressure, the more favorable for CO2 absorption and dissolution. The results of response surface process optimization showed that the calcium removal effect could reach 99.21% at normal temperature and pressure, raw water pH of 11.0, aeration rate of 200 mL/min, aeration time of 10 min by microbubble generator, and reverting pH of 12.8. Ca2+ mass concentration of the treated produced water could meet the requirements for preparing fracturing fluid for reuse. CO2 calcium removal was not only an effective technology that could efficiently remove calcium and reuse water resources, but also achieved permanent CO2 storage and conversion. It also helped to achieve “carbon neutrality” as soon as possible, making it an excellent choice for treating this kind of calcium containing produced water.

Key words: coalbed methane produced water, softening and calcium removal, water treatment, CO2

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