What is the material of N80 in the N80 oil casing

N80 oil casing and N80 seamless steel pipe are important equipment for oil drilling, and its main equipment also includes drill pipe, core pipe and casing, drilling collar and small diameter drilling steel pipe.

There are three lengths specified in the API standard for N80 oil casing and N80 seamless steel pipe: R-1 is 4.88~7.62m, R-2 is 7.62~10.36m, and R-3 is 10.36m to longer.

API 5CT N80 Casing:

N80 Casing is placed downhole to provide structural integrity to the wellbore and must withstand external-collapse pressure from rock formations and internal-yield pressure from fluid and gas. It must also hold its own deadweight and withstand the torque and transaxial pressure placed on it while running downhole.

API 5CT N80 Tubing:

N80 Tubing is placed within the casing. It is used to transport oil and gas from the source rock to the wellhead.

N80 oil casing and N80 seamless steel pipe are mainly used for oil well drilling for the support of the well wall during drilling and after completion to ensure the normal operation of the drilling process and the entire oil well after completion

The types and packaging of N80 oil casing and N80 seamless steel pipe are divided into two types: short threaded casing and its coupling and long threaded casing and its coupling according to SY/T6194-96 “oil casing”. According to SY/T6194-96, domestic casing should be bundled with steel wire or steel belt. Each sleeve and the exposed part of the clamp thread should be screwed with a protective ring to protect the thread.

N80 oil casing and N80 seamless steel pipe according to SY/T6194-96. The casing and its couplings are of the same steel grade. The sulfur content < 0.045%, and the phosphorus content < 0.045%.

N80 oil casing and N80 seamless steel pipe are taken according to the provisions of GB222-84 for chemical analysis. Chemical analysis is carried out in accordance with the provisions of the relevant part of GB223.

N80 oil casing and N80 seamless steel pipe American Petroleum Institute ARISPEC5CT1988 1st edition regulations. Chemical analysis according to the latest version of ASTME59 preparation, according to the latest version of ASTME350 chemical analysis.

Casing Pipe Specifications
Standards:	API SPEC 5CT
Model in Common Use:	2-3/8″, 2-7/8″, 3-1/2″, 4″, 4-1/2″
Length Range:	R1(6.10-7.32m), R2(8.53-9.75m), R3(11.58-12.8m)
Steel Grade (Casing Grades, Tubing Grades):	N80-1, N80-Q, L80, P110
Type of Screw Thread:	Non upset threaded end(NUE), External upset threaded end(EUE)
Specialties	Threading Heat treating External upset Drifting (Full-length, or just ends) Hydrostatic Testing Full third-party inspection capabilities (EMI, SEA, and Weld Line) Couplings – EUE, AB Modified, turned down, special clearance couplings Coating to customer specifications Pup Joints

PRODUCT	GRADE	DIAMETER	END TYPE
N80 TUBING	JFBNAU, L80, P110, 1% Chrome	2.375″ – 3.5″	Plain End EUE 8RD
N80 CASING	L80 HC, P110 HC	4.5″ – 9.625″ (J55, L80 HC, P110 HC) 10.75” – 20” (J55)	Plain End, STC, LTC, BTC

N80 TUBING SIZES, CASING DRIFT SIZES AND AVAILABLE GRADES:

OD	Wall	PE # / ft	T&C # / ft	Collar	API Drift	Available Grades
2.375″	.190	4.44	4.7	EUE, AB MOD	1.901	J-FBNAU, N80, L80, P110
2.875″	.217	6.17	6.5	EUE, AB MOD	2.347	J-FBNAU, N80, L80, P110
3.5″	.254	8.81	9.3	EUE, AB MOD	2.867	J-FBNAU, N80, L80, P110

Casing Sizes And Grades, Casing And Tubing Dimensions

Pipe Casing Sizes, Oilfield Casing Sizes & Casing Drift Sizes
Outer Diameter (Casing Pipe Sizes)	4 1/2″-20″, (114.3-508mm)
Standard Casing Sizes	4 1/2″-20″, (114.3-508mm)
Thread Type	Buttress thread casing, Long round thread casing, Short round thread casing
Function	It can protect the tubing pipe.

Oil Tube For Petroleum And Natural Gas Industries

Name of Pipes	Specification			Steel Grade	Standard
	D	(S)	(L)
	(mm)	(mm)	(m)
Petroleum Casing Pipe	127-508	5.21-16.66	6-12	J55. M55. K55. L80. N80. P110.	API Spec 5CT (8)
Petroleum Tubing	26.7-114.3	2.87-16.00	6-12	J55. M55. K55. L80. N80. P110.	API Spec 5CT (8)
Coupling	127-533.4	12.5-15	6-12	J55. M55. K55. L80. N80. P110.	API Spec 5CT (8)

API 5CT N80 Casing Tubing Chemical Composition, mass fraction (%)

Group	Grade	Type	C		Mn		Mo		Cr		Ni max.	Cu max.	P max.	S max.	Si max.
Group	Grade	Type	min.	max.	min.	max.	min.	max.	min.	max.	Ni max.	Cu max.	P max.	S max.	Si max.
1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16
1	H40	–	–	–	–	–	–	–	–	–	–	–	0.03	0.03	–
	J55	–	–	–	–	–	–	–	–	–	–	–	0.03	0.03	–
	K55	–	–	–	–	–	–	–	–	–	–	–	0.03	0.03	–
	N80	1	–	–	–	–	–	–	–	–	–	–	0.03	0.03	–
	N80	Q	–	–	–	–	–	–	–	–	–	–	0.03	0.03	–
	R95	–	–	0.45 c	–	1.9	–	–	–	–	–	–	0.03	0.03	0.45
2	M65	–	–	–	–	–	–	–	–	–	–	–	0.03	0.03	–
	L80	1	–	0.43 a	–	1.9	–	–	–	–	0.25	0.35	0.03	0.03	0.45
	L80	9Cr	–	0.15	0.3	0.6	0.9	1.1	8	10	0.5	0.25	0.02	0.01	1
	L80	13Cr	0.15	0.22	0.25	1	–	–	12	14	0.5	0.25	0.02	0.01	1
	C90	1	–	0.35	–	1.2	0.25 b	0.85	–	1.5	0.99	–	0.02	0.01	–
	T95	1	–	0.35	–	1.2	0.25 d	0.85	0.4	1.5	0.99	–	0.02	0.01	–
	C110	–	–	0.35	–	1.2	0.25	1	0.4	1.5	0.99	–	0.02	0.005	–
3	P110	e	–	–	–	–	–	–	–	–	–	–	0.030 e	0.030 e	–
4	Q125	1	–	0.35		1.35	–	0.85	–	1.5	0.99	–	0.02	0.01	–
a The carbon content for L80 may be increased up to 0.50 % maximum if the product is oil-quenched. b The molybdenum content for Grade C90 Type 1 has no minimum tolerance if the wall thickness is less than 17.78 mm. c The carbon content for R95 may be increased up to 0.55 % maximum if the product is oil-quenched. d The molybdenum content for T95 Type 1 may be decreased to 0.15 % minimum if the wall thickness is less than 17.78 mm. e For EW Grade P110, the phosphorus content shall be 0.020 % maximum and the sulfur content 0.010 % maximum. NL = no limit. Elements shown shall be reported in product analysis.

API 5CT N80 Casing Tubing Mechanical Properties

Standard	Type	Tensile Strength MPa	Yield Strength MPa	Hardness Max.
API SPEC 5CT	J55	≥517	379 ~ 552	—-
	K55	≥517	≥655	—
	N80	≥689	552 ~ 758	—
	L80(13Cr)	≥655	552 ~ 655	≤241HB
	P110	≥862	758 ~ 965	—-

Group	Grade	Type	Total elongation under load %	Yield strength MPa		Tensile strength min. MPa	Hardness a max.		Specified wall thickness mm	Allowable hardness variation b HRC
Group	Grade	Type	Total elongation under load %	min.	max .		HRC	HBW	Specified wall thickness mm	Allowable hardness variation b HRC
1	2	3	4	5	6	7	8	9	10	11
1	H40	–	0.5	276	552	414	–	–	–	–
	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	–	–	–	–
	R95	–	0.5	655	758	724	–	–	–	–
2	M65	–	0.5	448	586	586	22	235	–	–
	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	1	0.5	621	724	689	25.4	255	≤ 12.70 12.71 to 19.04 19.05 to 25.39 ≥ 25.40	3.0 4.0 5.0 6.0
	T95	1	0.5	655	758	724	25.4	255	≤ 12.70 12.71 to 19.04 19.05 to 25.39 ≥ 25.40	3.0 4.0 5.0 6.0
	C110	–	0.7	758	828	793	30	286	≤ 12.70 12.71 to 19.04 19.05 to 25.39. ≥ 25.40	3.0 4.0 5.0 6.0
3	P110	–	0.6	758	965	862	–	–	–	–
4	Q125	1	0.65	862	1034	931	b	–	≤ 12.70 12.71 to 19.04 ≥ 19.05	3.0 4.0 5.0
a In case of dispute, laboratory Rockwell C hardness testing shall be used as the referee method. b No hardness limits are specified, but the maximum variation is restricted as a manufacturing control in accordance with 7.8 and 7.9 of API Spec. 5CT.

API 5CT N80 Casing Tubing Steel color code

Name	J55	K55	N80-1	N80-Q	L80-1	P110
Casing	a bright green band	two bright green bands	a bright red band	a bright red band + a green band	a red band + a brown band	a bright white band
Coupling	entire green coupling + a white band	entire green coupling	entire red coupling	entire red coupling + a green band	entire red coupling + a brown band	entire white coupling

ISO/API casing/ API 5CT N80 Casing Tubing specifications

Codea		Outer diameter	Nominal weight (with thread and coupling) b,c	Wall thickness	End processing type
Codea		mm	kg/m	mm	H40	J55	M65	L80	N80	C90d	P110	Q125d
In	Lb/ft	mm	kg/m	mm	H40	K55	M65	C95	1, Q	T95d	P110	Q125d
1	2	3	4	5	6	7	8	9	10	11	12	13
9-5-8	32.3	244.48	48.07	7.92	S	–	–	–	–	–	–	–
9-5-8	36	244.48	53.57	8.94	S	SLB	SLB	–	–	–	–	–
9-5-8	40	244.48	59.53	10.03	–	SLB	SLB	LB	LB	LB	–	–
9-5-8	43.5	244.48	64.73	11.05	–	–	LB	LB	LB	LB	LB	–
9-5-8	47	244.48	69.94	11.99	–	–	LB	LB	LB	LB	LB	LB
9-5-8	53.5	244.48	79.62	13.84	–	–	–	LB	LB	LB	LB	LB
9-5-8	58.4	244.48	86.91	15.11	–	–	–	LB	LB	LB	LB	LB
10-3-4	32.75	273.05	48.74	7.09	S	–	–	–	–	–	–	–
10-3-4	40.5	273.05	60.27	8.89	S	SB	SB	–	–	–	–	–
10-3-4	45.5	273.05	67.71	10.16	–	SB	SB	–	–	–	–	–
10-3-4	51	273.05	75.9	11.43	–	SB	SB	SB	SB	SB	SB	–
10-3-4	55.5	273.05	82.59	12.57	–	–	SB	SB	SB	SB	SB	–
10-3-4	60.7	273.05	90.33	13.84	–	–	–	–	–	SB	SB	SB
10-3-4	65.7	273.05	97.77	15.11	–	–	–	–	–	SB	SB	SB
11-3-4	42	298.45	62.5	8.46	S	–	–	–	–	–	–	–
11-3-4	47	298.45	69.94	9.53	–	SB	SB	–	–	–	–	–
11-3-4	54	298.45	80.36	11.05	–	SB	SB	–	–	–	–	–
11-3-4	60	298.45	89.29	12.42	–	SB	SB	SB	SB	SB	SB	SB
13-3-8	48	339.72	71.43	8.38	S	–	–	–	–	–	–	–
13-3-8	54.5	339.72	81.1	9.65	–	SB	SB	–	–	–	–	–
13-3-8	61	339.72	90.78	10.92	–	SB	SB	–	–	–	–	–
13-3-8	68	339.72	101.19	12.19	–	SB	SB	SB	SB	SB	SB	–
13-3-8	72	339.72	107.15	13.06	–	–	–	SB	SB	SB	SB	SB
16	65	406.4	96.73	9.53	S	–	–	–	–	–	–	–
16	75	406.4	111.61	11.13	–	SB	SB	–	–	–	–	–
16	84	406.4	125.01	12.57	–	SB	SB	–	–	–	–	–
18-5-8	87.5	473.08	130.21	11.05	S	SB	SB	–	–	–	–	–
20	94	508	139.89	11.13	SL	SLB	SLB	–	–	–	–	–
20	106.5	508	158.49	12.7	–	SLB	SLB	–	–	–	–	–
20	133	508	197.93	16.13	–	SLB	–	–	–	–	–	–
S-Short round thread, L-Long round thread, B-Buttress thread
a. Code is used for ordering reference.
b. The nominal weight of threaded and coupled casing (column 2) is shown for reference only.
c. Martensitic chromium steel (L80 9Cr and 13Cr) differs from carbon steel in density. The shown weight of martensitic chromium steel is not an exact value. The mass correction factor 0.989 can be used.
d. C90, T95 and Q125 steel grade casing should be supplied according to specification, weight and wall thickness listed in the above table or order.

Codea		Outer Dia	Nominal weight (with thread and coupling) b,c	Wall Thickness	End processing type
Codea		mm	kg/m	mm	H40	J55	M65	L80	N801	C90d	P110	Q125d
In	Lb/ft	mm	kg/m	mm	H40	K55	M65	C95	N80Q	T95d	P110	Q125d
1	2	3	4	5	6	7	8	9	10	11	12	13
4-1-2	9.5	114.3	14.14	5.21	S	S	S	–	–	–	–	–
4-1-2	10.5	114.3	15.63	5.69	–	SB	SB	–	–	–	–	–
4-1-2	11.6	114.3	17.26	6.35	–	SLB	LB	LB	LB	LB	LB	–
4-1-2	13.5	114.3	20.09	7.37	–	–	LB	LB	LB	LB	LB	–
4-1-2	15.1	114.3	22.47	8.56	–	–	–	–	–	–	LB	LB
5	11.5	127	17.11	5.59	–	S	S	–	–	–	–	–
5	13	127	19.35	6.43	–	SLB	SLB	–	–	–	–	–
5	15	127	22.32	7.52	–	SLB	LB	LB	LB	LB	LB	–
5	18	127	26.79	9.19	–	–	LB	LB	LB	LB	LB	LB
5	21.4	127	31.85	11.1	–	–	LB	LB	LB	LB	LB	LB
5	23.2	127	34.53	12.14	–	–	–	LB	LB	LB	LB	LB
5	24.1	127	35.86	12.7	–	–	–	LB	LB	LB	LB	LB
5-1-2	14	139.7	20.83	6.2	S	S	S	–	–	–	–	–
5-1-2	15.5	139.7	23.07	6.98	–	SLB	SLB	–	–	–	–	–
5-1-2	17	139.7	25.3	7.72	–	SLB	LB	LB	LB	LB	LB	–
5-1-2	20	139.7	29.76	9.17	–	–	LB	LB	LB	LB	LB	–
5-1-2	23	139.7	34.23	10.54	–	–	LB	LB	LB	LB	LB	LB
6-5-8	20	168.28	29.76	7.32	S	SLB	SLB	–	–	–	–	–
6-5-8	24	168.28	35.72	8.94	–	SLB	LB	LB	LB	LB	LB	–
6-5-8	28	168.28	41.67	10.59	–	–	LB	LB	LB	LB	LB	–
6-5-8	32	168.28	47.62	12.06	–	–	–	LB	LB	LB	LB	LB
7	17	177.8	25.3	5.87	S	–	–	–	–	–	–	–
7	20	177.8	29.76	6.91	S	S	S	–	–	–	–	–
7	23	177.8	34.23	8.05	–	SLB	LB	LB	LB	LB	–	–
7	26	177.8	38.69	9.19	–	SLB	LB	LB	LB	LB	LB	–
7	29	177.8	43.16	10.36	–	–	LB	LB	LB	LB	LB	–
7	32	177.8	47.62	11.51	–	–	LB	LB	LB	LB	LB	–
7	35	177.8	52.09	12.65	–	–	–	LB	LB	LB	LB	LB
7-5-8	24	193.68	35.72	7.62	S	–	–	–	–	–	–	–
7-5-8	26.4	193.68	39.29	8.33	–	SLB	SLB	LB	LB	LB	LB	–
7-5-8	29.7	193.68	44.2	9.52	–	–	LB	LB	LB	LB	LB	–
7-5-8	33.7	193.68	50.15	10.92	–	–	LB	LB	LB	LB	LB	–
7-5-8	39	193.68	58.04	12.7	–	–	–	LB	LB	LB	LB	LB
7-5-8	42.8	193.68	63.69	14.27	–	–	–	LB	LB	LB	LB	LB
7-5-8	45.3	193.68	67.41	15.11	–	–	–	LB	LB	LB	LB	LB
7-5-8	47.1	193.68	70.09	15.88	–	–	–	LB	LB	LB	LB	LB
8-5-8	24	219.08	35.72	6.71	–	S	S	–	–	–	–	–
8-5-8	28	219.08	41.67	7.72	S	–	S	–	–	–	–	–
8-5-8	32	219.08	47.62	8.94	S	SLB	SLB	–	–	–	–	–
8-5-8	36	219.08	53.57	10.16	–	SLB	SLB	LB	LB	LB	LB	–
8-5-8	40	219.08	59.53	11.43	–	–	LB	LB	LB	LB	LB	–
8-5-8	44	219.08	65.48	12.7	–	–	–	LB	LB	LB	LB
8-5-8	49	219.08	72.92	14.15	–	–	–	LB	LB	LB	LB	LB

API Tubing Specifications

Size	Linear Mass lb/ft		Outside diameter		Wall thickness		Type of end-finish
	Linear Mass lb/ft		Outside diameter		Wall thickness		Grade
	Non-upset T﹠C	Ex-Upset T﹠C	ln.	mm	ln.	mm	J-55	L-80	N-801, N-80Q	C-90	T-95	P-110
2 3/8″	4.00	—	2.375	60.33	0.167	4.24	PN	PN	PN	PN	PN	—
	4.60	4.70	2.375	60.33	0.190	4.83	PNU	PNU	PNU	PNU	PNU	PNU
	5.80	5.95	2.375	60.33	0.254	6.45	—	PNU	PNU	PNU	PNU	PNU
	6.60	—	2.375	60.33	0.295	7.49	—	P	—	P	P	—
	7.35	7.45	2.375	60.33	0.336	8.53	—	PU	—	PU	PU	—
2 7/8″	6.40	6.50	2.875	73.03	0.217	5.51	PUN	PNU	PNU	PNU	PNU	PNU
	7.80	7.90	2.875	73.03	0.276	7.01	—	PNU	PNU	PNU	PNU	PNU
	8.60	8.70	2.875	73.03	0.308	7.82	—	PNU	PNU	PNU	PNU	PNU
	9.35	9.45	2.875	73.03	0.340	8.64	—	PU	—	PU	PU	—
	10.50	—	2.875	73.03	0.392	9.96	—	P	—	P	P	—
	11.50	—	2.875	73.03	0.440	11.18	—	P	—	P	P	—
3 1/2″	7.70	—	3.500	88.90	0.216	5.49	PN	PN	PN	PN	PN	—
	9.20	9.30	3.500	88.90	0.254	6.45	PNU	PNU	PNU	PNU	PNU	PNU
	10.20	—	3.500	88.90	0.289	7.34	PN	PN	PN	PN	PN	—
	12.70	12.95	3.500	88.90	0.375	9.52	—	PNU	PNU	PNU	PNU	PNU
	14.30	—	3.500	88.90	0.430	10.92	—	P	—	P	P	—
	15.50	—	3.500	88.90	0.476	12.09	—	P	—	P	P	—
	17.00	—	3.500	88.90	0.530	13.46	—	P	—	P	P	—
4″	9.50	—	4.000	101.60	0.226	5.74	PN	PN	PN	PN	PN	PU
	10.70	11.00	4.000	101.60	0.262	6.65	PU	PU	PU	PU	PU	PU
	13.20	—	4.000	101.60	0.33.	8.38	—	P	—	P	P	—
	16.10	—	4.000	101.60	0.415	10.54	—	P	—	P	P	—
	18.90	—	4.000	101.60	0.500	12.70	—	P	—	P	P	—
	22.20	—	4.000	101.60	0.610	15.49	—	P	—	P	P	—
4 1/2″	12.60	12.75	4.500	114.30	0.271	6.88	PNU	PNU	PNU	PNU	PNU	—
	15.20	—	4.500	114.30	0.337	8.56	—	P	—	P	P	—
	17.00	—	4.500	114.30	0.380	9.65	—	P	—	P	P	—
	18.90	—	4.500	114.30	0.43	10.92	—	P	—	P	P	—
	21.50	—	4.500	114.30	0.500	12.70	—	P	—	P	P	—
	23.70	—	4.500	114.30	0.560	14.22	—	P	—	P	P	—
	26.10	—	4.500	114.30	0.630	16.00	—	P	—	P	P	—
Non-Upset T﹠C-Non-upset threaded and coupled Ex-Upset T﹠C-External upset threaded and coupled P-Plain end N-Non-upset threaded and coupled U-External upset threaded and coupled

API 5CT N80 Casing Tubing Features

API 5CT N80 Casing Tubing is offered with a free length range from 8 to 13m on basis of the SY/T6194-96 norm. However, it is also available no less than 6m length and its quantity should be no more than 20%
Any deformation such as crease, hairline, separation, crack or scab is not acceptable on both inner and outer surfaces of the product. All these defects should be completely removed, and the removed depth must not exceed 12.5% of nominal wall thickness.
Deformations which mentioned above are not allowed to appear on the outer surface of API 5CT N80 Casing Tubing coupling
The surface of thread of coupling and API 5CT N80 Casing Tubing should be smooth without any burr, tear or other defects that may have a negative impact on the strength and close connection.