What types of structures does Octg casing have?

What types of structures does Octg casing have?

Oil pipes are mainly used for oil and gas well drilling and oil and gas transportation. It includes oil drilling pipe, oil casing, oil extraction pipe. Oil drill pipe is mainly used to connect drill collars and drill bits and transmit drilling power. The oil casing is mainly used to support the well wall during the drilling process and after the well completion, so as to ensure the drilling process and the normal operation of the entire oil well after the well completion. The oil suction pipe mainly transports the oil and gas at the bottom of the oil well to the surface.

The structure of Octg casing

Weight calculation
[(outer diameter-wall thickness)*wall thickness]*0.02466=kg/m (weight per meter)

Chemical composition
(1) According to the regulations of SY/T6194-96. The casing and its couplings shall be of the same steel grade. Sulfur content <0.045%, phosphorus content <0.045%;
(2) Take chemical analysis samples according to the provisions of GB/T222-84. Carry out chemical analysis according to the relevant parts of GB223;
(3) According to the first edition of API SPEC 5CT 1988 of the American Petroleum Institute. The chemical analysis shall be prepared according to the latest version of ASTME59, and the chemical analysis shall be carried out according to the latest version of ASTME350.

Physical properties
(1) According to the regulations of SY/T6194-96. For flattening test (GB246-97) tensile test (GB228-2010) and hydraulic test;
(2) Hydrostatic pressure test, flattening test, sulfide stress corrosion cracking test, hardness test (ASTME18 or E10 latest version), tensile test, transverse impact test ( ASTMA370, ASTME23 and the latest version of relevant standards), grain size determination (the latest version of ASTME112 or other methods).

Different Types of Casings Used During Oil Extraction:

Surface oil casing: protect the drilling well from being polluted by shallow water layers and shallow gas layers, support wellhead equipment and maintain the weight of other layers of casing.
Technical oil casing: separate the pressure of different layers so that the drilling fluid can flow normally and protect the production casing, and install anti-burst devices, leak-proof devices and tail pipes in the drilling.
Reservoir Oil Casing: Leads oil and gas out of subsurface reservoirs. Used to protect drilling wells and stratify drilling mud. When the oil casing is produced, the outer diameter is usually 114.3mm to 508mm.

According to SY/T6194-96 "Petroleum casing", the types and packaging of oil casing are divided into two types: short threaded casing and its coupling, and long threaded casing and its coupling.