Casing & Tubing

Sizes:

Out Diameter: 1.315″- 20″
Wall Thickness: 0.133″-0.500″
Length:R1(group1),R2(group2),R3(group3)

Materials & Grades:

Casing: J55, K55, N80, L80, P110

Application:

oil well extracting

borehole

borewell

Types:

Seamless Casing

ERW Casing

Connections:

P (Plain end)

STC (short threads)

LTC (long threads)

BTC (buttress threads)

Premium gas-tight connectors

Non-upset ends (NUE)

External upset ends (EUE)

Premium gas-tight connectors

Others special connectors

Chemical compositions of casing pipe

Standard	Grade	Chemical compositions（％）
API SPEC 5CT	J55	C	Si	Mn	P	S	Cr	Ni	Cu	Mo	V
	K55	0.34～0.39	0.20～0.35	1.25～1.50	≤0.020	≤0.015	≤0.15	≤0.20	≤0.20	/	/
	N80	0.34～0.38	0.20～0.35	1.45～1.70	≤0.020	≤0.015	≤0.15	/	/	/	0.11～0.16
	L80	0.15～0.22	≤1.00	0.25～1.00	≤0.020	≤0.010	12.0～14.0	≤0.20	≤0.20	/	/
	P110	0.26～0.395	0.17～0.37	0.40～0.70	≤0.020	≤0.010	0.80～1.10	≤0.20	≤0.20	0.15～0.25	≤0.08

 

Mechanical properties of casing pipe

 

Grade	Type	Total elongation under load (%)	Yield strength (min)Mpa	Yield strength (max)Mpa	Tensile strength min Mpa	Hardness Max (HRC)	Hardness Max (HBW)
J55	–	0.5	379	552	517	–	–
K55	–	0.5	379	552	655	–	–
N80	1	0.5	552	758	689	–	–
N80	Q	0.5	552	758	689	–	–
L80	1	0.5	552	655	655	23	241
L80	9Cr	0.5	552	655	655	23	241
L80	13Cr	0.5	552	655	655	23	241
C90	–	0.5	621	724	689	25.4	255
C95	–	0.5	655	758	724	–	–
T95	–	0.5	655	758	724	25.4	255
P110	–	0.6	758	965	862	–	–
Q125	All	0.65	862	1034	931	–	–

 

Casing Pipe Manufacturing Process:

Steel ingot heating → hydraulic punching → reheating → extension → periodic rolling → reheating → sizing → cooling → straightening → pipe cutting → inspection

1. An annular heating furnace is required for ingot heating;
2. Punching and reheating with hydraulic press;
3. The oil casing plant uses a two-roller guide plate extension machine for extension;
4. Re-use a disc heating furnace for periodic rolling, and use a non-entry furnace for reheating, cooling, straightening, pipe cutting, and inspection.