The Main Technical Specification of Type A,B,C Crossover Sub

Item

Description

Type

Upper connection

Lower connection

1

Kelly crossover sub

A or B

Kelly

Drill pipe

2

Drill pipe crossover sub

A or B

Drill pipe

Drill pipe

3

Crossover sub

A or B

Drill pipe

Drill collar

4

Drill collar crossover sub

A or B

Drill collar

Drill collar

5

Drill bit crossover sub

A or B

Drill collar

Drill bit

6

Swivel crossover sub

C

Swivel lower sub

Kelly

7

Fishing crossover sub

C

Kelly

Drill pipe

C

Drill pipe

Fishing tool