Introduction to  API specification 5CT seamless steel Pipe Oil Casing

API Specification 5CT Seamless Steel Pipe Oil Casing J55/K55/N80/L80/ C90/T95/P110/Q125 API Specification 5CT is a standard developed by the American petroleum institute (API) that specifies the technical requirements for seamless steel pipe oil casing used in the petroleum industry. This specification covers various grades of casing, including J55, K55, N80, L80, C90, T95, p110, and Q125. These grades are designed to meet specific performance requirements for different applications in Oil and gas wells. Seamless steel pipe oil casing is an essential component in oil and gas drilling operations. It is used to protect the wellbore and ensure the stability of the well during drilling and production. The casing is inserted into the wellbore and cemented in place to prevent the collapse of the wellbore and the migration of fluids between different geological formations. Hollow Round Seamless Oil Casing api 5ct l80 carbon steel Pipe API Specification 5CT sets the technical requirements for seamless steel pipe oil casing, including dimensions, mechanical properties, chemical composition, and testing procedures. The specification covers both plain-end and threaded-end casing, with various connection types, such as API round thread, API buttress thread, and non-upset tubing. One of the most commonly used grades of casing is J55. It has a minimum yield strength of 55,000 psi and a minimum tensile strength of 75,000 psi. J55 casing is suitable for shallow to medium-depth wells and has good resistance to corrosion and cracking. k55 casing is similar to J55 but has a higher minimum tensile strength of 95,000 psi. It is often used in wells with higher pressure and deeper depths. N80 Casing is a higher-grade material with a minimum yield strength of 80,000 psi. It has excellent mechanical properties and is suitable for medium to high-pressure wells. L80 casing has a minimum yield strength of 80,000 psi and is commonly used in wells with high pressure and high temperature conditions. It has good resistance to corrosion and is suitable for sour service applications.

							Calculated Mass c
			Nominal linear Mass T& C b,c	Wall thick– ness				em, Mass Gain or Loss Due to End Finishing d
Labels a		Outside diameter			Inside Diameter	Drift Diameter	Plain- end	kg
								Round Thread		Buttress Thread
							wpe
		D	kg/m	t	D	mm	kg/m	Short	Long	RC	SCC
		mm		mm	mm
1	2	3	4	5	6	7	8	9	10	11	12
10 3/4	32.75	273.05	48.74	7.09	258.9	254.91	46.5	13.94	—	— 15.38	— 3.03
10 3/4	40.5	273.05	60.27	8.89	255.3	251.31	57.91	11.91	—	14.21	1.86
10 3/4	45.5	273.05	67.71	10.16	252.7	250.82 e 248.77 246.23 246.33	65.87	11	—	14.21	1.86
10 3/4	45.5	273.05	67.71	10.16	252.7	244.48 e	65.87	11	—	13.05	0.7
10 3/4	51	273.05	75.9	11.43	250.2	244.48 e 243.94 243.94 241.40 241.40 238.86 238.86 234.95 231.80 228.60	73.75	10.11	—	13.05	0.7
10 3/4	51	273.05	75.9	11.43	250.2		73.75	10.16 f	—	12.25	–0.09
10 3/4	55.5	273.05	82.59	12.57	247.9		80.75	9.3	—	12.01	–0.34
10 3/4	55.5	273.05	82.59	12.57	247.9		80.75	9.35 f	—	12.25	–0.09
10 3/4	55.5	273.05	82.59	12.57	247.9		80.75	9.3	—	12.01	–0.34
10 3/4	55.5	273.05	82.59	12.57	247.9		80.75	9.35 f	—	11.07	—
10 3/4	60.7	273.05	90.33	13.84	245.4		88.47	8.42	—	10.87	—
10 3/4	60.7	273.05	90.33	13.84	245.4		88.47	8.47 f	—	9.98	—
10 3/4	65.7	273.05	97.77	15.11	242.8		96.12	7.54	—	9.74	—
10 3/4	65.7	273.05	97.77	15.11	242.8		96.12	7.60 f	—	—	—
10 3/4	73.2	273.05	108.93	17.07	238.9		107.76	—	—	—	—
10 3/4	79.2	273.05	117.86	18.64	235.8		116.95	—	—	—	—
10 3/4	85.3	273.05	126.94	20.24	232.6		126.19	—	—
11 3/4	42	298.45	62.5	8.46	281.5	279.40 e 277.50 275.44 272.39	62.56	13.27	—	—	—
11 3/4	42	298.45	62.5	8.46	281.5	269.88 e	62.56	13.27	—	— 16.04	—
11 3/4	47	298.45	69.94	9.52	279.41	269.88 e	67.83	12.42	—	14.5	—
11 3/4	54	298.45	80.36	11.05	276.4	269.65	78.32	11.23	—	13.12	—
11 3/4	60	298.45	89.29	12.42	273.6	269.65 e	87.61	10.17	—	13.12	—
11 3/4	60	298.45	89.29	12.42	273.6	269.88 e 267.36 264.92	87.61	9.77 f	—	13.12	—
11 3/4	60	298.45	89.29	12.42	273.6		87.61	10.17	—	13.12	—
11 3/4	60	298.45	89.29	12.42	273.6		87.61	9.77 f	—	—	—
11 3/4	65	298.45	96.73	13.56	271.3		95.27	—	—	—	—
11 3/4	65	298.45	96.73	13.56	271.3		95.27	—	—	—	—
11 3/4	71	298.45	105.66	14.78	268.9		103.4	—	—		—

C90 casing has a minimum yield strength of 90,000 psi and is used in wells with high pressure and high temperature conditions. T95 casing has a minimum yield strength of 95,000 psi and is suitable for deep and high-pressure wells. p110 casing has a minimum yield strength of 110,000 psi and is used in wells with high pressure and high temperature conditions. q125 casing