DRILL COLLARS
COMMAND-SMFI drill collars are thick-walled tubulars machined from solid steel bars and manufactured to specifications to meet and/or exceed API or NS-1 requirements. The quality of the heat treatment is critical in the production of raw materials and must be uniform and deep enough through the thickness of the bar to ensure the mechanical properties.
Drill collars are used as a component of the bottom-hole assembly (BHA) and provide the following:
Drill collars are used as a component of the bottom-hole assembly (BHA) and provide the following:
- Drilling weight-on-bit (WOB)
- BHA directional control
- Hole size integrity
- Stiffness to maintain hole straightness
- Clearance for the drill string
- Compressive and torsional loads
- Mitigate differential sticking and stuck pipe thanks to spiraled grooves
Product Performance
Drill collars come in slick and spiral-grooved designs with additional features for safe surface-handling and trouble-free operations. We provide the full range of collars manufactured in AISI 4145H-modified steel with mechanical properties guaranteed 1 inch below steel surface at ambient temperature.
Product range and features
Standard:
- ODs from 2-7/8” to 11”
- API 7.1 & 7.2 specifications
- Slick or spiraled
- API & H90 connections
- Fatigue resistance features (threads cold rolled, API pin stress relief groove, and API box bore-back)
- Range 2 and 3 lengths
- Phosphate coated threads
- Slip and elevator recess
- Pressed steel thread protectors
- A variety of steel grades: API, Sour Service, NS1, Low Temp, Non Magnetic
Options:
- Hardbanding
- Internal plastic coating for OD <6 1/2”
- High-performance double shoulder connections upon request
- Customized elevator and slip recess
- NS-1 or DS-1 or customers specifications
- Make and Break
Spiral Design + Slip & Elevator Recess
Spiral Design:
In order to reduce differential pressure sticking and wellbore contact, the surface of Drill Collars can be spiral-grooved. Spiral Drill Collars are the perfect solution for deep, directional or deviated drilling. Cross sections of the drill collars reduce the contact area with the wall of the hole.
Slip & Elevator Recess:
Slip and elevator recesses improve handling efficiency and safety. These features are machined in accordance with API standard RP7G. The upper radius of the elevator recess is cold rolled to increase the product service life. Slip and elevator recesses can be manufactured together or separately.
Drill Collar Material Table
| Connection | API | NS1 | NS1 | DS1 common / DS1 critical |
|---|---|---|---|---|
| API | All | OD < 9 1/2” | OD >= 9 1/2” | All |
| 4145H-modified | 4145H-modified | 4145H-modified | 4145H-modified | |
| 110 KSI | 110 KSI | 100 KSI | 110 KSI / 120 KSI |
| Connection | Sour Service | Sour Service | Sour Service | Sour Service |
|---|---|---|---|---|
| API | <= 6 3/4” OD | > 6 3/4” OD | <= 6 3/4” OD | > 6 3/4” OD |
| (with NACE test 45% SMYS) | (with NACE test 45% SMYS) | (No NACE test) | (No NACE test) | |
| (45% SMYS guaranteed) | (45% SMYS guaranteed) | |||
| ASCOWELL C | ASCOWELL C | ASCOWELL C | ASCOWELL C | |
| 110 KSI | 100 KSI | 110 KSI | 100 KSI |
Hardbanding (flush or raised)
Type B hardbanding is recommended on drill collars with slip and elevator recesses and is applied in a 4” long wear pad above the elevator recess, a 1” long wear pad above the slip recess and a 10” long wear pad under the slip recess. For drill collars with a slip recess only, type C hardbanding is applied to a 10” long wear pad under the slip recess and a 4” long wear pad above the slip recess. For drill collars without any recess, type A hardbanding is applied in a 10” long wear pad located 30” from the end of the pin.
Operational Benefits
COMMAND-SMFI has been producing high quality drill collars for over 60 years and we were the first company to manufacture small diameter drill collars from solid bars. Bars are trepanned in-house using specialty equipment to guarantee product performance and reliability. Our experience in material specification,mechanical properties, heat treatment, machining connections, and inspection are reflected in our product performance.
COMMAND-SMFI has been producing high quality drill collars for over 60 years and we were the first company to manufacture small diameter drill collars from solid bars. Bars are trepanned in-house using specialty equipment to guarantee product performance and reliability. Our experience in material specification,mechanical properties, heat treatment, machining connections, and inspection are reflected in our product performance.
