The crossover sub is used to crossover from one connection size to another or as the disposable component used to extend the connection life of a more expensive drill stem member.It is is the basic component in downhole work.
It is divided into drill string cross-over sub and tubing Cross-over sub.and in three basic types:
A Pin (male) * Box (female); B Pin (male) * Pin (male); C Box (female) * Box (female)
And we can design and manufacture special types of subs to satisfy clients’ ideas or drawings .
|Description||Upper junction block .||Lower junction block||Type|
|Kelly sub||Kelly||Drill pipe sub||Type A or B|
|Drill pipe sub||Drill pipe||Drill pipe sub||Type A or B|
|Crossover sub||Drill pipe||Drill collar||Type A or B|
|Drill collar sub||Drill collar||Drill collar||Type A or B|
|Bit sub||Drill collar||Bit||Type A or B|
|Swivel sub||Swivel lower sub||Kelly||Type C|
|Fish sub||Kelly||Drill pipe sub||Type C|
|Fish sub||Drill pipe||Fishing tool||Type C|
A type is straight OD sub, B type is reduced section sub, C type is left hand.
- The length of crossover subs is generally measured from shoulder to shoulder.
- Typical lengths range from 6″ – 28″. going up in increments of 2 inches with AISI 4145H, AISI 4145H Mod, AISI 4340, AISI 4140-4142 and Non-magnetic material.
- All connections are phosphate-coated or copper plated to improve resistance to corrosion.
- Crossover subs can be in three basic types: A Pin (male) * Box (female); B Pin (male) * Pin (male); C Box (female) * Box (female)
The Crossover sub is mainly used to connect upper and lower drill tools in different connectors in drilling operations. Also it can be used to protect other tooling in drill stem (called saver sub) or be used to deliver outgoing air to the bit face just above the bit (called bit sub).
How to order?
- 1. Identify sub use. Example: Kelly Sub, crossover drill pipe to drill collar, drill collar to drill collar, bit sub, etc
- 2. Overall length
- 3. Largest diameter
- 4. Bore ID
- 5. Size and type of upper and lower connections, indicating pin or box
- 6. Cast or pressed-steel thread protectors
- 7. For Reduced Section Subs, add: diameter of reduced section.(Length of reduced section: 8″, 12″, 18″ or 24″ For Bit Subs, add: float bore size and type if desired)
- Crossover Subs are manufactured from 4145M or 4140HT alloy steel.
- The connections are protected by a phosphate surface coating that minimizes galling on initial make-up.