Casing and tubing strings are the main parts of the well construction. All wells drilled for the purpose of oil or gas production (or injecting materials into underground formations) must be cased with material with sufficient strength and functionality.
What is casing pipe?
Casing is installed in layers, in sections of decreasing diameter that are joined together to form casing strings. The five types of casing string are conductor casing, surface casing, intermediate casing, casing liner, and production casing.
What is tubing?
The tubing is a tube that is lowered into the casing of the well when the well is being produced normally. From the well, the oil flows through the oil pipe into the ground and enters the gathering process. In the coal mining well, the combination of oil pipe, sucker rod and deep well pump draws oil to the ground and enters the gathering process.
Casing & Tubing
Standard:API SPEC 5CT
OD:
4 1/2",5",5 1/2",6 5/8",7",7 5/8"9 5/8",10 3/4",13 3/8",16"18 5/8",20"
Wall thickness:
5.21-16.13 mm
Thread type:
SC(Short round thread),LC(Longround thread),
BC(Buttress thread)
Length:
Rl(4.88-7.62m),R2(7.62-10.36m),
R3(10.36-14.63m)
Steel grade of API 5CT:
API 5CT J55,API 5CT K55,API 5CT N80,API 5CT L80,API 5CT P110.
