松辽盆地西部斜坡区换热井钻完井工艺实践

Practice of drilling and completion technology of heat exchange well in western slope area of Songliao Basin

合理开发利用地热资源对于推动能源结构转型、推进绿色清洁能源发展和实现新时代下“双碳”目标方面具有重要意义。松辽盆地西部斜坡区大安地区具有丰富的中深层地热资源,但该地区目前尚未施工中深层换热井,缺乏成熟的钻完井工艺技术经验总结。依据探采结合井取得的地质资料,总结该地区地层岩性特征和钻井施工难点,并从换热井井深、孔径、结构和井群平面几何分布形式分析,确定了适宜该地区的直井和定向井的换热井方案。根据地层岩性特征差异,总结了二开井段软泥岩地层和三开井段花岗岩地层钻进工艺,认为能够大大缩短完井周期。根据钻井结构设计中心管规格并在底部设置稳流器,保证了换热井底充分换热和井内水流平稳。通过对钻完井工艺的探讨、总结,能够为该地区开发利用干热型中深层地热能提供参考。

The rational development and utilization of geothermal resources is of great significance in promoting the transformation of energy structure,advancing the development of green and clean energy and realizing the goal of“double carbon”in the new era.The Da’an region in the western slope area of Songliao Basin is rich in medium-deep geothermal resources,but the medium-deep heat exchange wells have not been constructed in the region,and there is a lack of mature drilling and completion technology experience.Based on the geological data obtained from exploration-and production-combined wells,we summarize the formation lithology characteristics and drilling difficulties in this area,analyze the depth,aperture,structure of heat exchange wells and the geometric distribution of well groups,and determine the heat exchange well scheme suitable for vertical and directional wells in this region.According to the difference of formation lithology characteristics,the drilling technology of soft mudstone formation in the second section and granite formation in the third section is summarized,which can greatly shorten the completion period.In light of the drilling structure,the specification of the center pipe is designed and the flow stabilizer is set at the bottom to ensure the full heat exchange at the bottom of the well and the steady water flow in the well.The study can provide a reference for the development and utilization of dry heat medium and deep geothermal energy in the region.