地热井堵漏材料研究进展

Research Progress of Plugging Materials for Geothermal Wells

地层漏失是地热能勘探开发过程中经常遇到的问题,会影响施工安全、钻探效率和施工成本,尤其是地层稳定性差的热储层失返性漏失问题。当地热井非热储层段发生严重漏失时,采用常规的水泥、桥接堵漏材料等堵漏材料后堵漏成功率不高,亟需研发低成本、堵漏效果好、绿色环保的地热井堵漏材料。本文综述了地热井堵漏技术要求、堵漏材料研究与应用现状、地热井非热储层用堵漏材料和热储层用暂堵材料,分析了不同堵漏材料的优缺点,重点介绍了现有地热井堵漏材料的应用效果和自降解暂堵水泥、自降解型交联凝胶、温敏型形状记忆聚合物等3种热储层用暂堵材料的堵漏原理与进展,尤其是自降解型交联凝胶。随着地热能向深部勘探开发,提出了研发堵漏成功率高的广谱型堵漏技术、抗高温堵漏材料以及热储层段暂堵材料应用验证和热储层伤害评价等研究方向。研究成果对地热井钻遇漏失地层堵漏研究与工程实践具有重要的参考价值。

The problem of lost circulation occurs frequently during the development of geothermal wells,which will reduce drilling efficiency,and result in major economic loss and downhole accidents,especially the total loss of geothermal reservoir with poor formation stability.When severe loss occurs in non-reservoir section of geothermal well,conventional cement,bridging plugging materials and other plugging materials often have poor plugging effect.It is therefore urgent to develop low-cost,good plugging effect and environmental friendly plugging materials for geothermal wells.This work reviewed the technical requirements of plugging in geothermal wells,the research and application status of plugging materials,the plugging materials for non-reservoir and the temporary plugging materials for geothermal reservoirs.The advantages and disadvantages of different plugging materials were analyzed.We introduced the application effect of existing plugging materials in geothermal wells and plugging principle,progress of three kinds of temporary plugging materials for geothermal reservoirs,such as self-degradable temporary sealing cement,self-degradable crosslinked gel and temperature-sensitive shape memory polymer.With the exploration and development of deep geothermal energy,the research directions of plugging materials for geothermal wells were put forward,such as broad-spectrum plugging technology with high plugging success rate,high temperature resistant lost circulation materials and application verification of temporary plugging material.This study will provide important reference for the study and engineering practice of plugging materials for geothermal wells.