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.