casing tube and oil pipe

Casing tube is a kind of pipe to support oil and gas well sidewall to guarantee the drilling process and the whole oil well normal operation after drillings. According to different drilling depth and geological condition, each well uses several layers casing tube. Different from the oil pipe and drilling pipe, steel casing pipe is the one-time consumption materials without repeating using, so it adopts cement to fasten oil well. Therefore, the consumption of casing pipe is accounted for more than 70% of the total oil well pipe. Basing on the application, steel casing pipe can be divided into catheter, surface casing, intermediate casing and oil-string casing.

Casing Tube



Casing tube grades: H40， J55，K55， N80， L80， C90，T95， P110， Q125 etc.
Casing tube end processing forms: flush end, short round thread, long round thread, buttress thread and special shackle.

Physical properties:
★ According to the rule of SY/T6194-96, casing tube need to do flattening test (GB246-97), tension test (GB228-87) and hydraulic pressure test.
★ According to American Petroleum Institute APISPEC5CT1988 the first version, casing pipe also need to do hydrostatic testing, flattening test, sulfide stress corrosion cracking test, hardness test (ASTME18 or E10), tensile test, transverse impact test (ASTMA370, ASTME23 and related standard the latest version regulation).

Oil pipe is a kind of pipeline to transfer the crude oil and natural gas into the earth’s surface from hydrocarbon reservoir after completion of the drilling. It is used to support the pressure produced in the process of exploiting. Outside diameter of oil tube is generally from 60.3mm to 114.3mm. The oil tube end processing form has NU with thread and coupling, EU with thread and coupling and flush end.

Oil Pipe



Standard: API SPEC 5CT American Petroleum Institute
                  SYT 6194-2003 Petroleum and natural gas industry, oil gas casing pipe or oil tube
Application: Tripping into oil well to use as fluid or liquid injection pipe
Main Pipe Grade: J55、K55、N80、L80、P110 etc.
Classification: NU oil pipe, EU oil tube and IJ oil pipe

Dimension  Tolerance:

Types	Outer Diameter		Wall Thickness (s)
	OD (mm)	Allowed Tolerance (mm)
Casing Pipe	<114.3	±0.79	－12.5%
	≥114.3	－0.5%，+1%

Mechanical Properties:

Standard	Grades	Tensile Strength(Mpa)	Yield Strength(Mpa)	Elongation(%)	Hardness
API SPEC 5CT	J55	≥517	379～552	Check	-
	K55	≥517	≥655	-	-
	N80	≥689	552～758	-	-
	L80(13Cr)	≥655	552～655	≤241HB	-
	P110	≥862	758～965	-	-

Chemical Compositions:

Standard	Grade	Chemical Composition
		C	Si	Mn	P	S	Cr	Ni	Cu	Mo	V	Als
API 5CT	J55K55(37Mn5)	0.34～0.39	0.20～0.35	1.25～1.50	≤0.020	≤0.015	≤0.15	≤0.20	≤0.20			≤0.020
	N80(36Mn2V)	0.34～0.38	0.20～0.35	1.45～1.70	≤0.020	≤0.015	≤0.15				0.11～0.16	≤0.020
	L80(13Cr)	0.15～0.22	≤1.00	0.25～1.00	≤0.020	≤0.010	12.0～14.0	≤0.20	≤0.20			≤0.020
	P110(30CrMo)	0.26～0.35	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	≤0.020