Tube Casing is important to oil drilling equipment, its main equipment including drill pipe, tube and core casing, drill collars and drilling small diameter steel pipe and so on. Domestic steel casing to geological drilling made by the hot-rolled or cold drawn, steel with the "Geology" (DZ), said common grade steel casing has DZ40, DZ55, DZ753 species.
OCTG mainly used for oil and gas well drilling and oil and gas transportation. It includes oil drilling pipe, oil casing, tubing pumping. Major oil drill pipe drill collar and drill bit used to connect and pass drilling power. Casing is mainly used for drilling and completion of the wall after the support, to ensure that the conduct and completion of the drilling process, after the normal operation of the wells. Major pipeline pumping oil to the bottom of the wells, gas transmission to the ground. Oil well casing is run to maintain the lifeline. Because the geological conditions are different, the underground complex stress state, tensile, compressive, bending, torsional stress acting on the combined effect of the tube, the casing itself, which made a higher quality requirements. Once the casing itself is damaged for some reason, could lead the whole production wells, or even scrapped.
According to their strength steel casing can be divided into different grades of steel, that is J55, K55, N80, L80, C90, T95, P110, Q125, V150, etc. Well conditions, different depth, using different grades of steel. In the corrosive environment also requires the casing itself has anti-corrosion. Place in complex geological conditions also require casing with anti-collapsing properties.