Our Spiral Drill Collar is made from AISI 4145H modified alloy steel, and completely meets the requirement of API Spec 7-1 and SY/T5144 Standard. It is a kind of drill collar which adds three dextrogyrate spiral groove on the outer circle of ordinary drill collar when processing, and the purpose is to reduce the area of contact and friction with the well wall, which can effectively prevent the pressure sticking. The single weight of the spiral drill collar is round about 4% lighter than the ordinary drill collar with the same specification, and the shape and thread of the both ends are the same with the drill collar.
Materials: Drill collars are manufactured from AISI 4145H modified steel, and are supplied in the "as rolled" surface finish condition. Alternative surface finishes are available.
Trepanning and Heat Treatment: Drill collars are trepanned and drifted to API Spec 7-1. Full-length heat-treatment processes ensure that mechanical properties meet or exceed API Spec 7-1 requirements. A hardness range of 285-341, Brinell hardness and Charpy.
Main Features of Application of Our Drill Collar
- Put pressure on the drill bit
- To ensure the necessary strength of compression
- To reduce the vibration of the drill bit, swing, and beating, so that the drill work smoothly.
- In the process of drilling well deflection control.
Technical Specifications of Our Oilfield Drill Collar
| Type | OD(mm) | ID(mm) |
L(m)
±152.4mm
d |
DF(mm)
±0.4 |
NC23-31 | 79.4 | 31.8 | 9.14 | 76.2 |
| NC26-35 | 88.9 | 38.1 | 9.14 | 82.9 |
| NC31-41 | 104.8 | 50.8 | 9.14or9.45 | 100.4 |
| NC35-47 | 120.6 | 50.8 | 9.14or9.45 | 114.7 |
| NC38-50 | 127 | 57.2 | 9.14or9.45 | 121 |
| NC44-60 | 152.4 | 57.2 | 9.14or9.45 | 144.5 |
| NC44-60 | 152.4 | 71.4 | 9.14or9.45 | 144.5 |
| NC46-62 | 158.8 | 57.2 | 9.14or9.45 | 149.2 |
| NC46-62 | 158.8 | 71.4 | 9.14or9.45 | 150 |
| NC46-65 | 165.1 | 57.2 | 9.14or9.45 | 154.8 |
| NC46-65 | 165.1 | 71.4 | 9.14or9.45 | 154.8 |
| NC46-67 | 171.4 | 57.2 | 9.14or9.45 | 159.5 |
| NC50-70 | 177.8 | 57.2 | 9.14or9.45 | 164.7 |
| NC50-70 | 177.8 | 71.4 | 9.14or9.45 | 164.7 |
| NC50-72 | 184.2 | 71.4 | 9.14or9.45 | 169.5 |
| NC56-77 | 196.8 | 71.4 | 9.14or9.45 | 185.3 |
| NC56-80 | 203.2 | 71.4 | 9.14or9.45 | 190.1 |
| 6-5/8REG | 209.6 | 71.4 | 9.14or9.45 | 195.6 |
| NC61-90 | 228.6 | 71.4 | 9.14or9.45 | 212.7 |
| 7-5/8REG | 241.3 | 76.2 | 9.14or9.45 | 223.8 |
| NC70-97 | 247.6 | 76.2 | 9.14or9.45 | 232.6 |
| NC70-100 | 254 | 76.2 | 9.14or9.45 | 237.3 |
| 8-5/8REG | 279.4 | 76.2 | 9.14or9.45 | 266.7 |
| NC50-67 | 171.5 | 71.4 | 9.14or9.45 | 159.5 |
Our Service
1. We possess a 24 hr response system to provide convenient, fast, and effective pre-sale, during sale and after-sale service.
2. Our promise: Any equipment sold by Dongying Robust at any place in the world, we will provide after-sale service promptly and efficiently. Any equipment component damaged by manufacturing defect or quality problem during the warranty period, Dongying Robust will bear the direct cost of the damaged parts.
3. Warranty period: 18 months from the day that the unit leaves factory or 12 months from the date that the unit is put into use (choose the earliest one which comes to an end as the calculation standard).
Competitive Advantages
1. We offer high quality products at competitive price.
2. Shortest delivery time.
3. Flexible payment terms.
4. Timely after-sale service.
5. Most of our equipment can be replaceable with international brands.
6. Our products have been exported to Argentina, Egypt, US, Australia, Romania, Pakistan, Dubai, Abu Dhabi, Iran, India, Indonesia, Vietnam, Malaysia and many other countries.
