深部咸水层CO2地质封存钻井施工技术研究——以山东省首个咸水层CO2地质封存项目为例

Research on drilling construction technology for CO2 geological storage in deep saline aquifers： A case study of the first CO2 geological storage project in deep saline aquifers in Shandong Province

摘要:

井孔是CO₂注入目标层位的通道，是对注入地层中的CO₂及其对地层影响进行长期监测研究的基础和关键。相比常规的地热钻井，深部咸水层CO₂地质封存钻井需满足更高的密封性与耐腐蚀要求。本研究以山东省首个咸水层CO₂地质封存项目为例，列举了钻井施工难点，提供了主要的技术对策，为其他地区咸水层CO₂地质封存项目钻井施工提供依据。研究结果表明，钻井施工过程中采取快速钻进及相应钻井液护壁技术，解决井壁稳定性差问题。通过在取心管底部增加防止岩心掉落的卡簧装置，解决取心难的问题。采用高强度套管成井解决套管的气密性与安全性问题。采用BCE?750S型防腐蚀水泥固井射孔成井工艺，解决固井水泥腐蚀性问题。通过在CO₂注入管柱增加卡瓦封隔器装置，保障CO₂注入的气密性与稳定性。同时，采用石油开采领域的采油树井口装置，并安装压力监测表，解决井口装置长期承压及监测问题。

Abstract:

The wellbore serves as the pathway for CO₂ injection into the target formation and constitutes the fundamental basis for long-term monitoring and research on both the CO₂ injected into the formation and its impact on it. Compared with conventional geothermal drilling， the wellbore of CO₂ geological storage in deep saline aquifers requires higher standards of sealing and corrosion resistance. This study takes the first CO₂ geological storage project in deep saline aquifers in Shandong Province as an example， the difficulties in drilling construction are listed， the main technical countermeasures are offered， and guidance for drilling construction of other CO₂ geological storage projects in deep saline aquifers is provided. The research results show that during the drilling construction process， the rapid drilling and corresponding mud wall protection technologies are adopted to solve the problem of poor wellbore stability. The difficulty of core sampling was solved by adding a spring clip device to prevent core from falling at the bottom of the coring tube. High-strength casing is used to solve the gas tightness and safety problems of the casing. The integrated technology of cementing， perforating and well completion using BCE-750S anti-corrosion cement is adopted to solve the problem of cement corrosion. By adding the slips packer device to the CO₂ injection pipe string， the gas tightness and stability of CO₂ injection are guaranteed. At the same time， the oil wellhead device in the oil production field is adopted， and a pressure monitoring instrument is installed to solve the long-term pressure-bearing and monitoring problems of the wellhead device.