Drill Collar

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Drill Collar

Drill collar is obtained from rolled or forged AISI4145H chromium- molybdenum alloy steel. As a main component of a drilling motor, it is mounted at the bottom of drill string or drill pipe. It comes with the main features of up to 38~ 53mm in outside diameter or wall thickness, equivalently 4 ~ 6 times of drill string in wall thickness. Due to its large outside diameter, it has a high rigidity and high strength. During tripping or drilling operations, our collar is able to prevent broach from vibrating, shaking and bouncing, ensuring the stability of broach. It also will exert some pressure to the broach and guarantee the essential strength under compression. In addition to this, it can prevent well from slanting or tilting. To facilitate our drilling operations, slip groove and elevator groove are able to be mounted on the external surface of internal thread.

Generally speaking, there are three kinds of collars which include spiral drill collar, integral drill collar and non magnetic drill collar. The first one is machined with about three dextral spiral grooves and it used to reduce contact area with hole so as to avoid efficiently bit sticking from differential pressure. The second one is fabricated with threads. And the last one is ideal for survey during petroleum drilling process. It has the same structure with the second one. The third product is manufactured from N1310 low carbon alloy steel which is forged by chemicals analysis. N1310 low carbon alloy steel comes with low permeability and good mechanical properties. In addition, this low carbon alloy steel is built to meet international standards in hardness, ductibility, impact, and anti corrosion properties.

Technical Parameters
Drill Collar NumberO.D.I.D.LengthBeval DiameterRef. Bending Strength Ratio
NC23-3179.4 3 1/831.81 1/4915076.22.57:1
NC26-35(2-3/8 IF)88.9 3 1/238.11 1/2915082.92.42:1
NC31-41(2-7/8 IF)104.8 4 1/850.82 9150100.42.43:1
NC35-47120.7 4 3/450.82 9150114.72.58:1
NC38-50(3-1/2 IF)127.0 5 57.22 1/491501212.38:1
NC44-60152.4 6 57.22 1/49150&9450144.52.49:1
NC44-60152.4 6 71.42 13/169150&9450144.52.84:1
NC44-62158.8 6 1/457.22 1/49150&9450149.22.91:1
NC46-62(4 IF)158.8 6 1/471.42 13/169150&94501502.63:1
NC46-65(4 IF)165.1 6 1/257.22 1/49150&9450154.82.76:1
NC46-65(4 IF)165.1 6 1/271.42 13/169150&9450154.83.05:1
NC46-67(4 IF)171.4 6 3/457.22 1/49150&9450159.53.18:1
NC50-67(4-1/2 IF)171.4 6 3/471.42 13/169150&9450159.52.37:1
NC50-70(4-1/2 IF)177.8 7 57.22 1/49150&9450164.72.54:1
NC50-70(4-1/2 IF)177.8 7 71.42 13/169150&9450164.72.73:1
NC50-72(4-1/2 IF)184.2 7 1/471.42 13/169150&9450169.53.12:1
NC56-77196.8 7 3/471.42 13/169150&9450185.32.70:1
NC56-80203.2 8 71.42 13/169150&9450190.13.02:1
6-5/8 REG209.6 8 1/471.42 13/169150&9450195.72.93:1
NC61-90228.6 9 71.42 13/169150&9450212.73.17:1
7-5/8 REG241.3 9 1/276.23 9150&9450223.82.81:1
NC70-97247.6 9 3/476.23 9150&9450232.62.57:1
NC70-100254.0 10 76.23 9150&9450237.32.81:1
8-5/8 REG279.4 11 76.23 9150&9450266.72.84:1

DONGCHEN is a professional drill collar manufacturer in China. The wide range of products we offer includes pneumatic sample delivery device, continuous casting mould oscillation unit, bearing assembly and more.

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