API 5CT Steel Pipe
Product Introduction
API 5CT is the internationally recognized standard published by the American Petroleum Institute (API) for Casing and Tubing used in oil and gas wells. Unlike general line pipe, API 5CT pipes are designed to withstand the extreme conditions of a wellbore, including high pressure, corrosive fluids, and heavy mechanical loads. The specification covers two types of pipe: Casing, which lines the wellbore to prevent collapse and fluid leakage, and Tubing, which is placed inside the casing to transport oil and gas to the surface.
Product Features
Diverse Steel Grades: API 5CT defines specific groups of steel grades to suit different well depths and conditions. These include:
Standard Grades: H40, J55, K55, N80, and L80 (e.g., N80 offers a minimum yield strength of 552 MPa).
High-Strength Grades: C90, T95, and P110 (P110 offers a minimum yield strength of 758 MPa) for deep wells requiring high collapse resistance.
Corrosion-Resistant Grades: L80 13Cr and C90 13Cr, which contain chromium to resist corrosion in wells with high CO2 or H2S content.
Specialized End Finishes: The pipes are manufactured with precise threading to ensure a gas-tight seal. Common thread types include:
Short/Long Round Thread Coupling (STC/LTC): Standard for general applications.
Buttress Thread (BTC): Designed for high axial loads in deep wells.
Integral Joint (IJ) & Premium Connections: For high-pressure and high-integrity requirements.
Strict Testing Standards: API 5CT mandates rigorous quality control, including hydrostatic testing, hardness testing, and full-length body inspection to detect flaws that could lead to failure downhole.
Product Applications
Well Casing: Used to line the drilled wellbore to stabilize the formation, prevent the well from collapsing, and isolate underground fluid layers (e.g., separating fresh water from oil zones).
Production Tubing: Inserted inside the casing to serve as the conduit for extracting oil and natural gas from the reservoir to the surface facilities.
Drilling Operations: Used as drill pipe in specific contexts, though API 5D is the primary standard for drill pipe.
Geothermal & Water Wells: Also utilized in deep geothermal energy extraction and large-diameter water wells due to their durability and strength.
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