Drill Pipe is manufactured in accordance with API Spec 5DP and Spec 7-2. The steel grade is E75, X95, G105 and S135. The chemical composition of the steel is properly designed and strictly controlled. Drill Pipe features low sulfur and phosphorus content, pure steel quality, homogeneous structure, high machining precision of pipe body and thread, finishing surface, good mechanical properties and low-temperature toughness. In addition, we manufacture high-grade drill pipe such as anti-sulfur drill pipe and high anti-torque drill pipe with Double-Shoulder Tool Joints (DSTJ).

 

Drill Pipe Specifications:
(1) API Standard, OD: 2-3/8” - 6-5/8”, Grade: E75,  X95, G105, S135.
(2) Sulfur Resistant Drill Pipe with C95SS, C105SS Grades.
(3) Double Shoulder Tool Joint (DSTJ) Drill Pipe with high anti-torque ability.
(4) 5” EUE Drill Pipe jointly developed with Petrochina Tarim Oilfield Company.

   Heat treatment to Tool Joint                                                                                                    Threading                         

         MPI of Tool Joint                                                                                                              Ultrasonic Inspection of Weld Line

DSTJ (Double Shoulder Tool Joint)
API Tool Joints have been widely employed as threaded joints for every grades of drill pipes. In case of high grade drill pipe especially for S135 grade, the tool joint torsional yield strength is always lower than the pipe body torsional yield strength. and this unmatched torsional yield strength, sometimes, leads to the tool joint failure during drilling operation. The use of DSTJ (Double Shoulder Tool Joint) drill pipe is the solution of such problem.
PROPERTY
1. DSTJ is designed to be perfectly interchangeable with API Tool Joint. Any kind of accessories and conventional drill pipe can be used with DSTJ Drill Pipe.
2. DSTJ Tool Joint can stand higher operating torque than API Tool Joint.
3. DSTJ Tool Joint is suitable for sour well drilling due to the following reasons.
(1) Minimal hoop stress in the box.
(2) Lower tensile stress in the pin.
4.The internal diameter of DSTJ Tool Joint can be greater than the API Tool Joint.

5” EUE Drill Pipe
Product Characteristics:
(1) The Shape of MIU is changed to minimize stress concentration and lower the frequency of fatigue failures on MIU.
(2) The ID and upset area of Pin are upsized to reduce water horse power loss of mud and enhance cycle efficiency.
(3) Special materials are used for tool joint and pipe body to improve the mechanical properties of the drill pipe as a whole.
Comparison with API standard drill pipe:

  

Correlation Table of Drill Pipe Dimensions: Unit: mm
Specification	Tool Joint				Weld Line		Pipe Body
	OD	ID (PIN)	ID (BOX)	ID (WELD)	OD	ID	OD	ID
5” EUE	172	88.9	100	136	136	100	127	108
5” Normal S135	168.3	69.9	88.9	130.2	130.2	94.7	127	108.6

 

 

Correlation Table of Drill Pipe Mechanical Properties:
Specification	Tool Joint		Weld Line	Pipe Body
	Tensile Strength	Yield Strength	Impact Energy	Single Impact Energy	Average Impact Energy
	Mpa	Mpa	Jq	J	J
5” EUE	≧1000	931-1138	≧45	≧80	≧97
5” Normal S135	≧965	≧827	≧20	≧38	≧47

   

                                                                             Von Mises Equivalent Stress Distribution                       Von Mises Equivalent Stress Distribution
                                                                                  on Upset MIU with API Standard                                            on EUE Upset MIU