The drill collar is positioned at the lower section of the drill string assembly. Its primary function is to provide drilling pressure to the drill bit and ensure the rigidity of the drill string. As a core thick-walled tool, it is essential for achieving
| Drill Collar OD Range (mm) | Min. Yield Strength | Min. Tensile Strength | Elongation (%) | Min. Brinell Hardness (HBW) | V-notch Impact Test at 21°C ± 3°C (Avg/Min) |
|---|---|---|---|---|---|
| 3 1/8 in – 6 7/8 in | 110 ksi | 140 ksi | 13 | ≥ 285 | 40 ft·lbs / 35 ft·lbs |
| 79.4 – 174.6 mm | 758 MPa | 965 MPa | 54 J / 47 J | ||
| 7 in – 11 in | 100 ksi | 135 ksi | 13 | ≥ 285 | 40 ft·lbs / 35 ft·lbs |
| 177.8 – 279.4 mm | 689 MPa | 931 MPa | 54 J / 47 J |
Specifications
Dimensions (OD): 3-1/8“ to 11” (customizable)
Type
Solid drill collars, helical drill collars, non-magnetic drill collars, sulfur-resistant drill collars
Material:
4145H, W1813N, P530, P550, P650, etc.
Standards
API Spec 7-1, API Spec 7-2, DS-1, NS-1, etc.
nspection → End upsetting → Integral heat treatment → Pipe straightening → Pipe inspection (leakage, ultrasonic) → Physical and chemical testing → Finished pipe inspection → Cold straightening → Pipe end machining
Tool joint material incoming inspection → Sawing and forging (if necessary) → Joint upsetting → Joint marking → Joint heat treatment → Joint Brinell hardness testing → Physical and chemical testing → Ultrasonic inspection
Make-up/break-out test (if necessary) → Phosphating → Magnetic particle inspection → Joint marking → Cold rolling (if necessary) → Finished joint inspection → Joint thread machining → Joint profile machining
Final joint inspection
Drill pipe & joint end face preparation → Friction welding → Weld post-heating → Weld flash removal → Weld heat treatment (quenching, tempering) → Physical and chemical testing → Weld finishing → Magnetic particle inspection
Ultrasonic inspection → Finished product inspection → Hardbanding (if necessary) → Internal coating (if necessary) → Measuring, weighing and marking → Final inspection → Packaging → Delivery
