Wellbore casing, downhole casing, drilling casing, oil well casing, wellbore liner, production casing.

### Product Introduction I: Oil Country Tubular Goods (OCTG) - Casing

#### I. Product Overview

Oil country tubular goods (OCTG), specifically casing, are indispensable components in oil extraction. They support the wellbore, prevent collapse, and provide a conduit for the transportation of oil and gas. Tianjin Longkai Lai Company manufactures OCTG casings in strict compliance with international standards such as API 5CT, ensuring the reliability of product quality and performance. Our casings are widely used in both land-based and offshore oil and gas fields, meeting the demands of different well depths and geological conditions.

#### II. Outer Diameter Specifications

Tianjin Longkai Lai Company offers a variety of outer diameter specifications for OCTG casings to meet the needs of different customers. Common specifications include:

- 4.5 inches (114.3mm)

- 5.5 inches (139.7mm)

- 6.625 inches (168.3mm)

- 7 inches (177.8mm)

- 9.625 inches (244.5mm)

These casing sizes are manufactured using advanced production processes to ensure precision in outer diameter and uniformity in wall thickness, thereby enhancing the overall performance of the casing.

#### III. Yield Strength

Yield strength is a critical performance indicator for casing, determining the maximum pressure it can withstand underground. Tianjin Longkai Lai Company's casing offers a wide range of yield strengths to meet the needs of different extraction environments:

- J55 casing: Minimum yield strength of 35,000 psi (241 MPa)

- N80 casing: Minimum yield strength of 45,000 psi (310 MPa)

- P110 casing: Minimum yield strength of 75,000 psi (517 MPa)

- 13CR casing: Minimum yield strength of 75,000 psi (517 MPa), maximum yield strength of 105,000 psi (724 MPa)

These different strength grades of casing can adapt to various complex conditions, from shallow to deep wells and from conventional extraction to high-sulfur hydrogen environments.

#### IV. Tianjin Longkai Lai Company's Competitive Pricing Advantage

As a well-known manufacturer of oil country tubular goods, Tianjin Longkai Lai Company leverages its advanced production equipment and efficient production processes to offer competitive pricing. Our pricing advantages are mainly reflected in the following aspects:

1. Large-scale production: The company has a large modern production base that can achieve large-scale production, thereby reducing unit costs.

2. Direct sales: As the manufacturer, we directly engage with customers, eliminating intermediary links to ensure that customers can purchase high-quality products at the most favorable prices.

3. Customized services: We provide customized production services, adjusting product specifications and performance according to specific customer needs while maintaining reasonable prices.

#### V. Special Connection Advantages

Tianjin Longkai Lai Company has extensive experience in the design and manufacturing of special connections. Our casing uses advanced special connection technology, offering the following advantages:

1. High sealing performance: The special connection design ensures high sealing performance of the casing connections, effectively preventing gas and liquid leakage.

2. High-strength connection: The special connection can withstand higher tensile and compressive forces, ensuring the stability of the connection under complex working conditions.

3. Corrosion resistance: The special connection is treated with special processes, providing excellent corrosion resistance and extending the service life of the casing.

4. Quick installation: The special connection design simplifies the installation process, improves construction efficiency, and reduces construction costs.

#### VI. Application Scenarios

The OCTG casings produced by Tianjin Longkai Lai Company are suitable for a variety of oil and gas extraction environments, including but not limited to:

- Conventional oil and gas field extraction

- Deep and ultra-deep well extraction

- High-sulfur hydrogen (H₂S) and high-carbon dioxide (CO₂) environments

- Offshore oil and gas field extraction

Whether on land or offshore, our casings provide reliable solutions to ensure the safety and efficiency of the extraction process.

#### VII. Customer Case

Tianjin Longkai Lai Company has established long-term cooperative relationships with many internationally renowned oil companies. For example, a Middle Eastern oil company used our 13CR casing for deep well extraction. After years of use, the casing performance has been stable, with no quality issues arising, and has received high praise from the customer.

#### VIII. Conclusion

The OCTG casings produced by Tianjin Longkai Lai Company, with their outstanding performance, diverse specifications, competitive pricing, and advanced special connection design, have become the ideal choice for the oil and gas extraction industry. We are committed to providing customers with high-quality products and excellent services to help them achieve efficient and safe extraction goals.