管柱脱落的故障现象是：运行电流很低，基本上是电机的空载电流，除了有一股一股的气外，井口基本上无产液，正发循环时油套连通。The failure phenomenon of the string is: the running current is very low, basically the motor's no load current. Besides the gas with a single strand of gas, the wellhead basically has no liquid production, and the oil sleeve is connected when circulating.减少管柱脱落的措施有：将油管上扣扭矩由原来的值提高到值；采用油管螺纹垫片；定子上的装卸短节采用防松螺纹连接；采用油管锚或张力封隔器固定螺杆泵。The measures to reduce the falling off of the pipe string are as follows: increase the torque from the original value to the maximum value; use the oil pipe screw gasket; the loading and unloading joint on the stator is connected by loosening screw thread; and use the oil pipe anchor or tension packer to fix the screw pump.



Ｆ、抽油杆F, sucker rod所使用的抽油杆是常用的普通抽油杆、空心抽油杆和连续抽油杆，可根据油井确定。The sucker rod used is commonly used as a common 1sucker rod, hollow sucker rod and continuous sucker rod, which can be determined according to the oil well.Ｇ、定子扶正器G, stator centralizer定子扶正器为有一定弹性的笼形装罩，每一对由两半构成，中间大、两端小。作用是使定子居中和减小定子的摆动。The stator centralizer is a cage shaped cover with a certain elasticity. Each pair is made up of two halves, large in the middle and ***all at both ends. The function is to make the stator middle and reduce the stator wobble.Ｈ、锚定装置H, anchoring device对于没有封隔器的井和泵挂深度浅的井，用于固定定子、消除摆动和防止定子脱扣。采用普通的锚定装置即可。For wells without packers and shallow wells with deep pumps, it is used to fix the stator, eliminate the swinging and prevent the tripping of the stator. A common anchoring device can be used.

单螺杆泵工作时，两端分别作用着液体的吸排压力，因此对螺杆要产生轴向推力。螺杆泵厂家建议对于压差小于10千克力/cm2的小型泵，可以采用止推轴承。此外，还通过主动螺杆的***油孔将高压油引入各螺杆轴套的底部，从而在螺杆下端产生一个与轴向推力方向相反的平衡推力。

　　单螺杆泵和其它容积泵一样，当泵的排出口完全封闭时，泵内的压力就会上升到使泵损坏或使电动机过载的***程度。所以，螺杆泵厂家建议使用时在泵的吸排口处，就必须设置安全阀。

　单螺杆泵有以下优点：

　　1)因为泵内的回转部件惯性力较低，故可使用很高的转速;

　　2)结构坚实，安装***容易;

　　3)单螺杆泵的压力和流量范围宽阔。压力约在3.4-340千克力/cm2，流量可达18600cm3/分;

　　4)单螺杆泵的吸入性能好，具有自吸能力;

　　5)与其它回转泵相比，对进入的气体和污物不太敏感;

　　6)流量均匀连续，振动小，噪音低;

　　7)单螺杆泵的运送液体的种类和粘度范围宽广。

　　单螺杆泵的缺点是，螺杆的加工和装配要求较高;泵的性能对液体的粘度变化比较敏感。