What is OCTG and what are its main components?
OCTG stands for Oil Country Tubular Goods. It is a family of seamless or welded steel pipes specifically designed for use in oil and gas wells. OCTG is essential for drilling, completing, and producing from a well. The three primary components are:
Casing: The structural "backbone" of the well. It is run into the drilled hole to prevent the wellbore from collapsing and to isolate different underground formations (e.g., freshwater zones from oil/gas zones).
Tubing: The conduit placed inside the casing. It serves as the channel through which oil or gas is brought to the surface during production.
Drill Pipe: The heavy, thick-walled pipe used to transmit drilling fluid to the drill bit and to rotate the bit during the drilling process.
What steel grades do you supply, and what do they mean?
We supply a comprehensive range of API 5CT standard steel grades, each designed for specific well conditions. The grade indicates the minimum yield strength (in ksi) and the material's properties.
Group 1 (Standard Grades):
H40, J55, K55: General-purpose grades for shallow to medium-depth wells with low to moderate pressure. K55 is commonly used for surface casing.
Group 2 (Higher Strength):
N80 (Type 1 & 2): A versatile, high-strength grade suitable for a wide range of applications, including intermediate and production casing.
L80 (Type 1, 9Cr, 13Cr): Designed for sour service environments (containing H₂S). L80-13Cr offers superior corrosion resistance.
Group 3 (High Performance):
C90, T95: Used in high-pressure, high-temperature (HPHT) wells and sour service applications.
P110, Q125: High-strength grades for deep wells and high-pressure environments where maximum burst and collapse resistance are required.
What types of connections (threads) are available?
The connection is a critical component of any OCTG string. We offer both standard API connections and advanced Premium Connections.
API Connections:
Short Round Thread (STC): A simple, cost-effective connection for shallow wells.
Long Round Thread (LTC): Similar to STC but with a longer thread for slightly better performance.
Buttress Thread (BTC): Provides high tensile strength and is suitable for deeper, heavier wells.
Premium Connections (Non-API):
These are engineered for extreme conditions, offering superior gas-tight sealing, high tensile strength, and excellent fatigue resistance. They are essential for HPHT wells, deepwater applications, and complex well geometries. We can supply various premium connection types based on your specific project requirements.
How do you ensure the quality and integrity of the pipes?
We implement a rigorous multi-stage quality control process to ensure every pipe meets the required specifications:
Chemical Composition Analysis: Verifying the steel grade's elemental makeup.
Mechanical Property Testing: Including tensile, yield, hardness, and impact tests.
Hydrostatic Testing: Every pipe is pressure-tested to ensure it can withstand specified internal pressures without leaking.
Non-Destructive Testing (NDT): We utilize advanced NDT methods such as Ultrasonic Testing (UT) and Electromagnetic Testing (ET) to detect any internal or surface imperfections.
Dimensional Inspection: Precise measurement of outside diameter (OD), wall thickness, weight, and length.
What is your typical lead time and packaging for export?
Lead Time: For standard API grades and sizes, our lead time is typically 15-30 days after receiving the deposit and final order confirmation. For specialized grades or premium connections, the timeline may be longer.
Packaging: To ensure safe ocean transport, all OCTG products are securely packed. Threads are protected with steel or plastic protectors, and pipes are bundled with steel straps. We can also apply anti-corrosion oil or varnish and use wooden crates for extra protection as per customer requirements.
