大套变井连续油管带压注水泥塞技术

Under Pressure Cementing for the Severe Casing Deformation Well Through CT

华北油田留70-85井具有井筒严重套变、井口带压、地层存在漏失等特点,采用常规的60.3 mm油管难以下入到井筒的设计深度进行泵注暂堵水泥塞施工作业。鉴于此,利用连续油管(CT)刚度小、柔性好、可带压作业的特点,采用50.8 mm连续油管下入到套变井筒中进行泵注暂堵水泥塞施工作业。该井在施工过程中严格控制排量和泵压,解决了地层漏失、水泥浆高压失水闪凝等难题。结果表明,在此类井筒中采用连续油管注水泥塞具有作业精度高、施工作业安全可靠等特点,水泥塞质量合格,为今后套损套变井带压修井中的泵注水泥浆暂堵施工提供了重要的参考。

The Liu70-85 well in Huabei oilfield is characterized by severe casing deformation,high pressure,and formation leakage. The conventional 60. 3mm tubing can not be lowered into the designed depth of the wellbore to complete operation of the pump temporary plugging cement. In view of this,by using advantages such as small stiffness,flexible,and being operated under high pressure of the coiled tubing( CT),50. 8mm type of continuous tubing is selected for this well's cementing plug operation. During the operation,discharging amount and pumping pressure of the CT are strictly controlled to solve problems such as formation leakage,cement slurry's flash setting under high-pressure condition successfully. The results show that cementing plug with coiled tubing has features of high precision,safety and reliable for this kind of well,plugging cement is qualified,which provides an important reference for the operation of the severe casing deformation well with high pressure.