Drill Rods Top Subs with API Regular Box, API Regular Pin thread
Drill pipe joint buckle type
Internal Flush connection threads:
Internal Flush connection threads: mainly used for outer thickening
drill pipe. The characteristic is that the inner diameter of the
drill pipe is the same, and the flow resistance of the drilling
fluid is small; but the outer diameter is large and easy to wear.
Full Hole Connection threads:
Full Hole Connection threads: mainly used for thickening drill rods
inside and outside. It is characterized in that the drill pipe has
two inner diameters, and the drilling fluid flow resistance is
greater than the inner flat type, but the outer diameter is smaller
than the regular type.
Regular Connection threads:
Regular Connection threads: mainly used for inner thickening drill
pipe and drill bit, fishing tools. The characteristic is that the
inner diameter of the joint inner diameter is smaller than the
inner diameter of the pipe body, and the drilling fluid has large
flow resistance, and the relative flow resistance is the largest
among the three buckle types, but the outer diameter is the
smallest and the strength is large.
The above three types of joints are all V-shaped threads, but the
buckle type, the buckle length, the taper and the size are all very
different.
NC type thread
Number style connection threads
The digital (NC) series connector is a US national standard coarse
thread series. It has been adopted as an international standard by
the API. NC threads are also V-threaded, and some NC-type joints
have the same pitch circle diameter, taper, pitch and thread length
as the old API standard joints and can be used interchangeably.
Most of the oil drill pipe joints are in the form of outer
thickening or inner and outer thickening. The outer diameter of the
drill pipe joint is larger than the outer diameter of the pipe
body. During the drilling process, the inner wall or the casing is
in constant contact with the friction, resulting in wear and tear,
so as to avoid broken joints. For drilling accidents such as poles
and trips, drill pipe joint wear belts must be provided on the
drill pipe female joint.
