Integral heavy weight drill collars

Integral heavy weight drill pipe is manufactured from AISI 4142H-4145H modified drill collar material according to SY/T 5146-1997,thick-walled pipe called integral heavy weight drill pipe was developed to provided a gradual transition from the heavy drill collars to the relatively light weight drill pipe. This intermediate weight pipe has a wall thickness of approximately,and helps prevent stress concentration at the top of the drill collars. It also allows you to drill at higher rpms, reducing torque and differential pressure sticking. It is intended primarily for directional drilling. Because it bends easily, it simplifies directional control and minimizes connection fatigue problems common to high angle or horizontal drilling. The reduced number of pipe failures and increased drill stem service also make it appropriate for some straight-hole applications.

Size	Outside Diameter C	Inside Diameter E	Connection				Body		Single of Weight
			Type	Outside Diameter		Bevel edge Of pin and box shoulder DFmm	Upset Section Size
							Central Section Dmm	End Section Bmm
	mm	in		mm	in
I Type
ZH-JZ55-51/2FH-I	139.7	5 1/2	5 1/2FH	92.1	3 5/8	170.7	152.4	144.5	730
ZH-JZ50-NC50-I	127	5	NC50(4 1/2IF)	76.2	3	154	139.7	130.2	700
ZH-JZ45-NC46-I	114.3	4 1/2	NC46(4IF)	71.4	2 13/16	145.3	127	117.5	585
ZH-JZ35-NC38-I	88.9	3 1/2	NC38	52.39	2  1/16	116.3	101.6	92.1	370
II Type
ZH-JZ50-NC50-II			NC50(4 1/2IF)	165.1	6 1/2	154	139.7	130.2	945
ZH-JZ45-NC46-II			NC46(4IF)	158.8	6 1/4	145.3	127	117.5	790

Mechanical Property
Yield strength Ò0.2	Tensile strength Òb	Elongation 4(%)	Hardness(Brinell)	IMPACT ＆118alue(CHARPY-V)
758	964	13	285--341	54