一种新型煤层气旋转控制头旋转总成的温升影响因素分析

Analysis on influence factors of temperature rise in rotary assembly of a new CBM rotary control head

可靠有效的冷却润滑系统是旋转控制头安全、高效工作的保证。结合现有成熟技术,设计出一种集冷却润滑系统与旋转总成为一体的新型旋转控制头。为确保其旋转总成冷却润滑的要求,建立1/2实体三维数值模型,分析了密封井压、钻杆转速、井口偏心距对其温升的影响。结果表明:三影响因素均是旋转总成温升的主要因素,随三者的增大旋转总成的热平衡最高温升呈非线性增大,但在其运转所允许的温升范围内;三影响因素对旋转总成的动密封系统温升的影响最为明显,说明动密封系统是旋转总成的主要热源点;井口偏心距的增大较另外两种影响因素的增大,对旋转总成的热平衡最高温升值影响更大,进一步证实了旋转控制头安装过程中减少井口偏心距的重要性。

The reliable and effective cooling and lubrication system is the assurance for safe and efficient working of rotary control head. Combined with the existing mature technology,a new rotary control head with the cooling and lubrication system and rotary assembly as a whole was designed. In order to satisfy the cooling and lubricating requirements of rotary assembly,a 3D numerical model representing 1 /2 solid was built,and the influence of sealing pressure,rotation speed of drill pipe and wellhead eccentricity on the temperature rise in rotary assembly was analyzed. The results showed that all the three influence factors are the main factors of temperature rise in rotary assembly. The maximum temperature rise in thermal equilibrium of rotary assembly present non- linear increase with the increase of each factor,but within the allowable range of temperature rise for operation. The influence of three factors on the temperature rise of dynamic sealing system of rotary assembly is the most obvious,which explains that the dynamic sealing system is the main heat source of rotary assembly. Compared with the increase of other two influence factors,the increase of wellhead eccentricity has a larger influence on the maximum temperature rise in thermal equilibrium of rotary assembly,which further confirms the importance of reducing the wellhead eccentricity during the installation process of rotating control head.