Zhengzhou Chenghe Machinery Co., Ltd. is located in Zhengzhou, the capital of Henan province, Central China. We are specially dealing with two types of products: The first category includes a variety of special steel forgings and machining parts, representative products are : 1. oilfield stabilizer (finished and the Forged billet), drill pipe, drill collar, pup joint, and all kinds of union, oil casing; 2.  Roller; 3. PQF Mandrel bar 4. non-standard gear, shaft with deep holes ( length up to 12 meters), large motor shaft, engine crankshaft, hydraulic cylinder for mining machinery and other machining products; The second category includes machineries and equipments, the main products are: 1. petroleum solid control equipment, including mud circulation tank, shale shaker, mud cleaner (AIO), centrifugal sand pump, YQ series of gas-liquid separator and other 10 kinds of products; 2. packaging machinery, including transparent film packaging machine, Film Binding Machine, etc..

 

Our products have been exported to Middle East, Europe, India, USA, Southeast Asia etc. countries and districts and mainly used for metallurgy, machinery, petroleum, shipping, chemical and packaging industries.

 

With a perfect quality control system, high standard quality and reliable product performance, timely delivery and excellent after-sales service, Chenghe has won wide acclaim from customers, sincerely welcome customers at home and abroad send enquiries or come to negotiate.

1.    Drill collars

 

Drill collars are manufactured from AISI 4145H or 36CrNiMo4 modified steel, and are supplied in the" as rolled" surface finish condition. Alternative surface finishes can be provided.

Trepanning and Heat treatment :
Drill collars are trepanned and drifted to API Spec 7. Full-length heat-treatment processes ensure that mechanical properties meet or exceed API Spec 7 requirements. A hardness range of 285-341, Brinell Hardness and Charpy ＆#129;gV＆#129;h notch minimum impact strength of 40 ft-lb at 70OF are guaranteed one inch below the surface.
Connections NC23 NC26and NC31(2 3/8 IF and 2 7/8 IF) have a sufficient steel thickness for machining stress-relief grooves.

Drill collar material and process traceability are maintained from receipt of mill certified raw material to completion of all the manufacturing. Serial numbers are die stamped on bar bidies.

Rigid Inspection Procedures:
We inspect all our drill collars to comply with API standards . These inspections include visual dimensional checks as well as ultrasonic inspections over the entire body of the drill collar.

Cold Rolling:
Drill collar thread roots, as well as elevator recess upper radii, are cold-rolled. Cold rolling creates a compressive recess upper radii stress condition that increases fatigue life by minimizing crack initiation.

 

Phosphate-coated or copper plating:

All connections are phosphate-coated or copper plating to improve resistance to galling.

Slip groove. elevator groove and size :

Our company offers optional slip and elevator recesses to improve handling efficiency and safety. The upper radius of the elevator recess is cold can be used together or separately. Unless otherwise specified, slip and elevator recesses are machined in compliance with API RP 7G guidelines.

Thread protectors:
HUANJIE company offers steel and cast steel and plastic steel thread protectors for its drill stem products.

 

 

 

 

2. Non-magnetic drill collars

3.Spiral drill collars

Spiral grooves let mud circulate freely around the drill collar to equalize pressure and prevent a seal from forming. The reduces the occurrence of differential pressure sticking Spiral prevents differential sticking without spiral. Spiral collars are wide used because of their maintenance features. The special grooves decrease the volume of the contact between the well side and the pipe, it leads to the decrease of the "tack" of the pipe and to turning of the drill pipe string. The weight of round drill collars will be reduced approximately 4-6% by spiral conversion.

 

4.Kellys

We can offer square and hexagonal kellys are available up to 46 feet long. Our kellys are made from AISI 4142H-4145H modified alloy bars that are quenched and tempered full length. A hardness range of 285 to 341 BHN and a minimum impact ＆#118alue of 40ft-lbs are maintained one inch below the surface at room temperature. All ends and center drive sections-trepanned to provide true bores. They are drifted to API specifications, and all connections are machined. Kellys are stamped with the API monogram, where applicable.

 

size and type of square kelly (in):

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size and type of hexagonal kellys (in):

 

5. Integral heavy weight drill pipes

 

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.

 

6. Tri-spiral heavy weight drill pipe

 

We developed tri-spiral heavy weight drill pipe for applications where standard heavy weight drill pipe can fail-extended reach or horizontal drilling. tri-spiral heavy weight drill pipe features more weighter joint and better hole cleaning characteristics than standard heavy weight drill pipe, providing optimum performance in severe drilling conditions.
Tri-spiral integral heavy weight drill pipe is designed to handle maximum stress to save time and reduce drilling costs, especially in tough drilling environments.

 

Tri-spiral Integral heavy weight drill pipe
Size	Outside Diameter C		Inside Diameter E		Tool Joint				Pipe		Single of Weight kg
					Type	Outside Diameter A		Bevel edge Of pin and box shoulderDFmm	Upset Section Size
	mm						in		in
I Type(<9300mm>)
ZH-LJZ55	139.7	5 1/2	92.1	3 5/8	5 1/2FH	177.8 184.2	7 7 1/4	170.7	152.4	144.5	850
ZH-LJZ55	127.0	5	76.2	3	NC50(4 1/2 IF)	165.1 168.3	6 1/2 6 5/8	154.0	139.7	130.2	735
ZH-LJZ55	114.3	4 1/2	71.4	2 13/16	NC46(4IF)	158.8	6 1/4	145.3	127.0	117.5	615
ZH-LJZ55	88.9	3 1/2	52.39	2 1/16	NC38(3 1/2IF)	120.7	4 3/4	116.3	101.6	92.1	375

 

7. Drill system accessories

 

pup joints:

We can provide any type of pub joints using the same material as our drill collars. All connections are phosphatecoated to improve resistance to galling. Standard lengths are 5 ft,10 ft, 15ft, and 20ft,additional sizes are available upon request.Integral pub joints have the same properties in tensile, yield and torsional strength as compared with S-135 which has the same ID , all products are conformed with API Specification.

 

Lift subs and lift plugs:

Lift subs and lift plugs are manufactured to the same specifications used for drill collars.
(A) lift plug plate diameter approximately 2±larger than drill collar diameter.
Lift subs can be ordered with top connection

 

Rotary subs:
Rotary subs are available in standard lengths of 36”or 48”. Rotary subs are manufactured from drill collar material trepanned and drifted to API Spec 7 requirements. Include Kelly saver sub, straight OD subs and reduced section.

 

8.Tool joint

 

Tool joint are turned, bored and faced prior to heat treatment by the Quench and temper process to produce a uniform microstructure, high ductility, and other mechanical properties in accordance with API specifications. The heat treatment is done under controlled atmophere for consistent quality. The tensile and impact properties are verified by destructive testing of a tool joint representing each process batch, every tool joint is subjected to wet magnetic particle inspection,
both transverse and longitudinal, to insure the absence of defects.

Threads are precision machined on CNC lathes. All connections are 100%inspected for thread parameters and phosphatized or copper plating for antigalling treatment.

9. Drill Pipes