The tubing is divided into flat tubing(NU), thickened tubing (EU) and integral joint tubing (IJ). Flat tubing

means that the end of the tubing is directly threaded and coupled without thickening. Thickened tubing

refers to the two ends after external thickening, then the car threads and with coupling. Integral joint

tubing refers to one end through the internal thickening of the external threads of the vehicle, the other

end through the external thickening of the internal threads of the vehicle, directly connecting without

coupling.

Function of tubing: oil and gas extraction: After completion of well drilling and cementing, the tubing is

placed in the casing of the reservoir to extract oil and gas to the surface. Water injection: When the

downhole pressure is insufficient, water is injected into the well through the tubing. Steam injection: In the

process of heavy oil thermal recovery, heat insulation tubing is used to input steam into the well.

Acidification and fracturing: In order to improve the production of oil and gas wells in the late stage of

well drilling, acidizing and fracturing media or fixed-line substances need to be input into the reservoir,

and the media or solidified substances are transported through the tubing.