Top Drive Center Pipe - Core Power Transmission Component of Oil Drilling Top Drive Equipment

I. Product Positioning

The top drive center pipe is a core power transmission and fluid channel component of the oil drilling top drive system (top drive drilling unit). It is made of high-quality alloy structural steel, sulfur-resistant carbon steel, and special stainless steel as base materials, through precision forging, CNC deep hole machining, heat treatment strengthening, and surface anti-corrosion treatment. Specifically designed for torque transmission, drilling fluid delivery, and high-pressure sealing during drilling, it undertakes the key functions of driving the drill string to rotate, guiding drilling fluid directly to the bottom of the well, and bearing complex downhole loads. It is a core component ensuring efficient drilling and safe operation of top drive equipment, suitable for high-pressure, corrosive, and vibrating working conditions such as onshore/offshore oil and gas drilling and shale gas development.

II. Core Advantages

1. High-pressure bearing and impact resistance, reliable structure: Selected high-quality base materials such as 42CrMo, 35CrMo, and sulfur-resistant steel (N80QS, L80-13Cr). After quenching and tempering heat treatment (quenching + high-temperature tempering), the tensile strength is ≥1100MPa, yield strength ≥950MPa, and impact toughness ≥35J/cm². It can stably bear the drilling pressure (maximum applicable drilling pressure ≤5000kN), torque (maximum transmitted torque ≤60kN・m), and downhole impact loads during drilling. The structural safety factor is ≥1.8, eliminating the risk of fracture and deformation.
2. High-precision deep hole machining, efficient fluid transmission: Adopting CNC deep hole drilling machines and honing processes for precision machining, the inner hole diameter tolerance is ≤±0.03mm, roundness error ≤0.015mm, and inner hole surface roughness Ra ≤0.8μm, ensuring smooth delivery of drilling fluid (including drilling additives and cuttings) with a pressure drop loss ≤0.5MPa/10m. The connecting threads at both ends (API standard threads or custom threads) are precision turned and roll-strengthened, with a thread accuracy grade of 2A/2B and excellent sealing performance. The drilling fluid leakage rate is ≤1×10⁻⁷Pa・m³/s.
3. Wear and corrosion resistance, adapting to harsh working conditions: The inner hole is treated with plasma-sprayed cemented carbide or nitriding, with a surface hardness of HRC 60-65. The wear resistance is more than 3 times that of ordinary pipes, capable of resisting drilling fluid erosion and cutting wear. The outer surface adopts chrome plating, anti-corrosion coating, or stainless steel material, which can resist drilling fluid corrosion, marine salt spray erosion, and corrosion from acidic media such as hydrogen sulfide (H₂S) and carbon dioxide (CO₂). The service life is extended by 2-3 times in harsh environments such as sulfur-containing oil and gas wells and offshore drilling.
4. Customized adaptation, wide scene compatibility: Can customize pipe size (outer diameter φ89-φ245mm, inner diameter φ50-φ180mm, length 1500-6000mm), connecting thread type (API NC, IF, REG threads), and strengthening process (inner hole wear-resistant coating, outer surface anti-corrosion treatment) according to top drive equipment models (such as 150t, 250t, 350t class top drives) and drilling conditions. It is suitable for working pressure ≤70MPa, working temperature -40℃~150℃, and compatible with various drilling fluid systems such as water-based, oil-based, and synthetic-based.
5. Excellent fatigue resistance, long service life: Shot peening is used to eliminate surface residual stress, and the pipe transition fillet and structural design are optimized to avoid stress concentration. The fatigue resistance is improved by more than 40%, and the fatigue life is ≥5×10⁶ cycles, meeting the 24-hour continuous operation demand of top drive equipment, reducing downtime and replacement frequency, and lowering drilling costs.

III. Key Technical Parameters

IV. Application Fields

• Oil and gas drilling: Onshore oil and gas wells, offshore platform drilling top drive equipment;
• Shale gas development: Shale gas horizontal wells, extended-reach well top drive drilling systems;
• Deep/ultra-deep well drilling: High-temperature and high-pressure deep wells, ultra-deep well top drive equipment;
• Special oil and gas reservoir drilling: Sulfur-containing oil and gas wells, acidic medium oil and gas well top drive systems;
• Geothermal drilling: Geothermal resource development drilling top drive equipment;
• Coalbed methane drilling: Coalbed methane exploration and development top drive drilling devices.

V. Quality Assurance

1. Raw materials are selected from high-quality steel of well-known domestic and foreign steel mills, providing material certificates, spectral analysis reports, mechanical property test reports, and sulfur corrosion resistance test reports (for sulfur-containing working conditions). 100% spectral detection and appearance inspection are conducted before warehousing;
2. The entire production process complies with ISO 9001:2015 quality system and API Spec 7-1 oil drilling tool standards. Key processes (forging, heat treatment, deep hole machining, thread machining) are equipped with online testing equipment to achieve 100% full process inspection;
3. Finished products undergo non-destructive testing such as ultrasonic testing (UT), magnetic particle testing (MT), and penetrant testing (PT) to ensure no internal cracks, inclusions, pores, or other defects. At the same time, full-item testing such as dimensional accuracy, thread accuracy, and water pressure sealing test (test pressure ≥1.5 times the working pressure) is completed;
4. Provide customized design (including strength check, structural simulation optimization), installation guidance, on-site technical support, and top drive center pipe repair services. Free technical support and troubleshooting are provided during the warranty period, and precise matching and customization according to top drive equipment drawings are supported.