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 "V" notch minimum impact strength of 40 ft-lb at 70 F are guaranteed one inch below the surface.
Drill collar material and process trace ability are maintained from receipt of the mill's certified raw material to completion of manufacturing. Serial numbers are die stamped on bar bodies.
Rigid Inspection Procedures:
We inspect all our drill collars to ensure compliance with API SPEC 7-1 standard. These inspections include visual dimensional checks as well as ultrasonic inspections over the entire body of the drill collar.
Drill collar thread roots, as well as elevator recess upper radius, are cold-rolled. Cold rolling creates a compressive recess upper radius stress condition that increases fatigue life by minimizing crack initiation.
Phosphate-coated or Copper Plating:
All connections are phosphate-coated or copper plated to improve resistance to corrosion.
Slip Groove, Elevator Groove and Size:
Saigao offers optional slip and elevator recesses to improve handling efficiency and safety. Unless otherwise specified, slip and elevator recesses are machined in compliance with API spec 7-1 guidelines.
Eccentric-weight drill collar is an effective anti-deviation drilling tool, with high drill pressure used in oblique areas, rectifying oblique as well.
When drilling directional wells eccentric-weight drill collar is an effective tool to reduce oblique or straighten the good hole using high drilling pressure.
Eccentric-weight drill collar has the advantages of simple structure, convenient use, connected directly to a common drill collar without centralizers, and greatly convenient for sinking in, fishing and milling operations.
Eccentric-weight drill collar runs downhole safely, the danger of leakage or bit freezing hard to appear.
As a dependable drill collar and spiral drill collar manufacturer, Saigao is and will always be your best partner by supplying the top drill collar and spiral drill collar.
|Drill collar thread type||OD||ID||Length (mm)|
|NC26-35 ( 23/8 ″ IF )||79.4||3 1/8||31.8||11月4日||9150|
|NC31- 41(27/8 ″ IF)||88.9||31/2||38.1||11月2日||9150|
|NC38-50(31/2 ″ IF)||120.7||Apr-43||50.8||2||9150|
|NC44-60||152.4||6||57.2||4月21日||9150 (or) 9450|
|NC44-62||152.4||6||71.4||2 13/16||9150 (or) 9450|
|NC46-62(4 ″ IF)||158.8||Apr-61||57.2||4月21日||9150 (or) 9450|
|NC46-65(4 ″ IF)||158.8||Apr-61||71.4||2 13/16||9150 (or) 9450|
|NC46-67(4 ″ IF)||165.1||Feb-61||57.2||2 13/16||9150 (or) 9450|
|N50-67(4 1/2 ″ IF)||165.1||Feb-61||71.4||2 13/16||9150 (or) 9450|
|NC50-70(4 1/2 ″ IF)||171.4||Apr-63||57.2||2 13/16||9150 (or) 9450|
|NC50-70(4 1/2 ″ IF)||171.4||Apr-63||71.4||2 13/16||9150 (or) 9450|
|NC50-72(4 1/2 ″ IF)||177.8||7||57.2||2 1/4||9150 (or) 9450|
|NC50-70(4 1/2 ″ IF)||177.8||7||71.4||2 13/16||9150 (or) 9450|
|NC50-72(4 1/2 ″ IF)||184.2||Apr-71||71.4||2 13/16||9150 (or) 9450|
|NC56-77||196.8||Apr-73||71.4||2 13/16||9150 (or) 9450|
|NC56-80||203.2||8||71.4||2 13/16||9150 (or) 9450|
|6 5/8 ″ REG||209.6||Apr-81||71.4||2 13/16||9150 (or) 9450|
|NC61-90||228.6||9||71.4||2 13/16||9150 (or) 9450|
|7 5/8 ″ REG||241.3||9 1/2||76.2||3||9150 (or) 9450|
|NC70-97||247.6||Apr-93||76.2||3||9150 (or) 9450|
|NC70-100||254||10||76.2||3||9150 (or) 9450|
|8 5/8 ″ REG||279.4||11||76.2||3||9150 (or) 9450|
No 12111,Jingshi Road, Lixia District, Jinan City, Shandong Province. P.R. China
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