梨树断陷页岩气水平井钻井关键技术

Key Drilling Techniques for Shale Gas Horizontal Well in Lishu Faulted Depression

为解决部署在梨树断陷的首口页岩气水平井梨页1HF井存在的井壁失稳风险高、机械钻速低、固井施工难度大、井眼轨迹控制难度大等技术难题。在梨页1HF井施工过程中,通过综合应用油基钻井液、旋转导向地质导向、双凝双密度水泥浆等技术,并进行了钻头优选和钻具组合优化。施工结果表明井眼稳定,井眼轨迹平滑,水平段共完成进尺1020 m,储层钻遇率92.7%,固井质量优秀。该井实现了安全、高效钻进,实际钻井周期22.56 d,较设计钻井周期缩短了14.94 d,平均机械钻速7.98 m/h,较设计提高了82.19%。该井良好的施工效果,可见对后续梨树断陷页岩气水平井施工具有积极的指导和借鉴作用。

The first shale gas horizontal well Liye 1HF deployed in the Lishu faulted depression came across some problems such as high risk of wellbore instability,low rate of penetration,difficult in cementing construction,and difficulty in wellbore trajectory control.To deal with it,many techniques were comprehensively applied in the construction process of the Liye 1HF well.They were the oil-based drilling fluid,rotary-steering geo-steering,double-condensation double-density cement slurry and other technologies,and the optimization of the drill bit and the drilling tool combination.The construction results show that the wellbore is stable and the wellbore trajectory is smooth.The horizontal section has a total footage of 1020 m,the reservoir drilling rate is 92.7%,and the cementing quality is excellent.The well achieves safe and efficient drilling.The actual drilling cycle is 22.56 d,which is shortened by 14.94 d compared with the designed drilling cycle,and the average rate of penetration is 7.98 m/h,which is 82.19%higher than the design.It is concluded that the good construction effect of the well has positive guidance and reference for the subsequent construction of shale gas horizontal wells in the Lishu faulted depression.