连续管振动减摩钻井技术研究

Research on the CT Vibration Antifriction Drilling Technology

连续管振动减摩钻井技术可以较好地降低连续管钻井过程中的摩擦阻力。构建了连续管振动减摩钻井模型,对连续管的受力及运动进行了分析。通过搭建振动钻进试验台,模拟激振器在连续管屈曲段的微井眼振动能量,开展相应的振动试验对连续管振动钻井技术进行了验证,并对不同条件下的井筒摩阻进行了比较分析。分析结果表明,轴向振动减摩效果优于旋转振动减摩效果,适当增加振动频率可提高减摩效果,应优先发展轴向振动减摩工具与钻井工艺方法;合适的振动幅度、振动频率与连续管的整体力学性能、地层特性有关;单纯通过井下工具虽可达到减摩降阻效果,但增加了井下结构的复杂性,给钻井带来了额外风险。

The coiled tubing （CT） vibration antifriction drilling technology can satisfactorily reduce the frictional resistance in the process of CT drilling. The CT vibration antifriction drilling model was established and the force and motion of CT were analyzed. The vibration drilling test bench was built to simulate the micro-hole vibration energy of the exciter in the CT buckling section. The corresponding vibration test was carried out to verify the technology and make a comparative analysis of well bore frictional resistance in different conditions. The analysis shows that the axial vibration antifriction effect is better than the rotating vibration antifriction effect. A suitable increase of vibration frequency can improve the antifriction effect. Priority should be given to the development of the axial vibration antifrietion tool and the drilling technology. The proper vibration amplitude and frequency are related to the whole mechanical property of CT and the formation property. Although mere dependence on downhole tools can achieve the effect of friction reduction and resistance decrease, the complexity of the downhole structure will increase, bringing about the additional risk for drilling.