复杂地层压力条件下长裸眼全井封固配套固井技术

中原油田为了控制成本，调整井只下入了表层套管和油层套管，为防止地层中的流体腐蚀套管，需进行超长封固段固井，但中原油田经过长期的注水开发，地层压力非常复杂，严重影响了固井质量。针对这种情况，中原油田通过科技攻关形成了“动、静结合，局部封堵、全井防窜，外引内推、控制返速”等一套较为完整的复杂地层压力条件下长裸眼固井技术。现场应用表明，采用该套固井技术后，固井一次成功率100％，固井合格率达到98％以上，较好地解决了复杂地层压力条件下长裸眼全井封固段固井质量问题。

The Supporting Techniques for Cementing a Long Open Hole under Complex Formation Pressure

In order to decrease drilling costs, only surface and production casing strings are run in adjusting wells in Zhongyuan Oilfield. Regarding such scenario, it is necessary to cement ultra-long open hole sections to prevent casings from corrosion caused by formation fluids, however, Zhongyuan Oilfield has experienced long term water-injection operations, its formation pressure system becomes complicated which severely affects cementing qualities. In dealing with such situations, Zhongyuan Oilfield has established a series of integrated cementing techniques--combining dynamic and static, sealing hole sections, overall preventing from channeling, controlling annular velocity, etc. After employing such cementing techniques, Zhongyuan Oifield achieved 100G cementing success rate and 98% cementing qualification rate, and solved long-open-hole-cementing problems under complicated formation pressures.