Oil tubing falls into three types: Non‑upset Tubing (NU), External‑upset Tubing (EU) and Integral‑joint Tubing (IJ).

NU：Pipe ends remain non‑upset, threaded and coupled directly.

EU：Both ends are externally upset, then threaded and fitted with couplings.

IJ：One end is externally upset with external thread; the other end is externally upset with internal thread, for direct

        connection without couplings.

Functions of Oil Tubing：

1. Oil & Gas Production: After well drilling and cementing, tubing is run inside casing to bring oil and gas up to           

surface.

2. Water Injection: Inject water downhole through tubing when down‑hole pressure is insufficient.

3. Steam Injection: Insulated tubing delivers steam for thermal recovery of heavy‑oil wells.

4. Acidizing & Fracturing: Deliver acidizing and fracturing media or proppants through tubing at later

well‑completion stage to boost well output.

Steel Grade：H40, J55, K55, N80-1, N80-Q, L80-1,L80-9Cr, L80-13Cr, P110, Q125 etc

SIZE：OD: 42.16 MM-114.3 MM(1.66"--4 1/2") WT: 3.56-16mm(2.3ppf-26.1ppf)

Standard：API 5CT, GB, ISO11960, GOST

Type：NU, EU, IJ

Length：R1, R2, R3