Packing box

Abstract

The invention provides a packing box. The packing box comprises an upper fixed seal part, a lower connector and a retractable sleeve, the upper fixed seal part is fixed to a polished rod and comprises a seal packing box, seal packing and a pressing cap, wherein the polished rod can be sleeved with the seal packing box, the seal packing is arranged in the seal packing box, and the pressing cap can be used for pressing the seal packing into the seal packing box so that the seal packing and the polished rod can be fixedly sealed. The lower connector is used for being connected with a Christmas tree. The retractable sleeve can retract and stretch between the upper fixed seal part and the lower connector so that the distance between the upper fixed seal part and the lower connector can be changed. The first end of the retractable sleeve is connected with the seal packing box in a sealed mode, and the second end of the retractable sleeve is connected with the lower connector in a sealed mode. According to the packing box, a sliding seal part is not needed, the packing box will not be abraded, and therefore the service life of the packing box is greatly prolonged. Meanwhile, the labor amount of workers is reduced, and while the faults of an oil pumping system are reduced, a lot of oil pumping machine electric energy is saved.

Description

technical field [0001] The invention relates to the technical field of wellhead accessories for oil production in oil fields, in particular to a maintenance-free packing box for wellhead sealing during oil production with rods. Background technique [0002] The packing box is a sealing device for the polished rod at the wellhead of the pumping unit, which plays a role in sealing the annular space between the oil pipe and the polished rod during the normal operation of the oil well. In the case of no failure in the pumping well, the most likely problem at the production wellhead is oil leakage from the packing box. Although engineers and technicians have developed various self-aligning packing boxes, as the pumping unit drives the polished rod to move up and down repeatedly, the polished rod and the sealing packing will wear out for a long time, and the packing box will leak after a period of time, and it needs to be tightened again Packing cap. Due to repeated tightening, ...

AI Technical Summary

Problems solved by technology

Although engineers and technicians have developed various self-aligning packing boxes, as the pumping unit drives the polished rod to move up and down repeatedly, the polished rod and the sealing packing will wear out for a long time, and the packing box will leak after a period of time, and it needs to be tightened again Packing cap

Due to repeated tightening, the friction between the sealing packing and the polished rod increases, and the pumping unit wastes a lot of electric energy to overcome the useless work generated by this friction

In addition, after tightening to a certain extent, tightening again does not work. At this time, it is necessary to stop the pumping unit and replace the sealing packing, which increases the workload

More importantly, during the shutdown process, the sand contained in the produced oil in the tubing will sink and sink between the oil well pump barrel and the oil well pump plunger. When the packing box is replaced and started twice , Sand stuck or wax stuck accidents often occur, the entire oil well needs to be taken out for inspection, and the maintenance cost is further increased

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