Heavy Weight Drill Pipe Specs & Selection

Heavy Weight Drill Pipe Specs is important to understand as it is the entrance of the heavy weight drill pipe design. In this article, we will discuss its specs and how to select in the drill string design. In addition to that, we will talk about its main functions. you can also download the specs sheets from any size of heavy weight drill pipes.

Heavy Weight Drill Pipes Definition

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In the past, the two main components of the Drill String consisted of the Drill Pipe and the Drill Collars. The point where the relatively small OD and flexible Drill Pipe connects to the large stiff Drill Collars is called the Transition Zone. Oilfield studies have shown that almost all of the Drill Pipe fatigue failures are the result of an accumulation of fatigue damage occurring when the Drill Pipe joints were run in the Transition Zone or were stressed above the endurance limit in crooked holes. Downhole data has indicated that the large change in diameter at the transition zone caused accelerated fatigue damage as a result of the concentration of cyclic bending stress reversals in the bottom joints of the flexible Drill Pipe since the stiff Drill Collars bend very little from these stress reversals. So heavy weight drill pipe specs definition will be a drill pipes with higher thickness to withstand the stress in the transition zone.

HWDP Function

Before starting ti talk about heavy weight drill pipe specs, let’s understand its function. Heavy weight drill pipe is used to absorb the stresses being transferred from the stiff Drill Collars to the relatively flexible Drill Pipe. The major HWDP benefits are:

• Increased wall thickness
• Longer tool joints
• Uses more hard facing
• May have a long central upset section

Heavy Weight Drill Pipe Specs

• Heavy Weight Drill Pipe Quality Standard: API 7 and API 5DP.
• Heavy Weight Drill Pipe Steel Grade: Integral heavy weight drill pipe: AISI 4145HM; Welded HWDP : AISI 1340.
• Heavy Weight Drill Pipe pipe body, AISI 4140HM.
• Heavy Weight Drill Pipe Outer Diameter: 2 7/8” – 6 5/8”.
• Heavy Weight Drill Pipe Weight Range: 6.27#/FT through 27.72#/FT.
• Heavy Weight Drill Pipe Lengths: Range 2 and Range 3.
• Heavy Weight Drill Pipe End Finishes: Internal Upset, External Upset, Plain End Upset, Non Upset.
• Heavy Weight Drill Pipe Tool Joint type：NC38、NC46、NC50、5-1/2 FH.

Heavy Weight Drill Pipe Specs Sheets From work strings international

PDF Spec Sheet	OD(in)	Connection	TubeID (in)	Adjusted Weight (lb/ft)	Tool/Joint OD (in)	TJ ID (in)	TJ Yield (ft-lbs)	M/U Torque (ft-lbs)	Prem Tube Tensile (lbs)	Type	Design
Spec Sheet	3 1/2	NC38	2 1/4	23.29	4 3/4	2 1/4	19,200	9,600 – 11,520	237,600	Standard	Conventional
Spec Sheet	3 1/2	NC38	2 1/4	23.29	4 3/4	2 1/4	17,600	8,800 – 10,560	621,000	Integral	Conventional
Spec Sheet	3 1/2	NC38	2 1/4	29.72	4 3/4	2 1/4	19,200	9,600 – 11,520	237,600	Standard	Spiral
Spec Sheet	3 1/2	NC38	2 1/4	23.73	4 7/8	2 1/4	22,900	11,450 – 13,740	237,600	Standard	Conventional
Spec Sheet	3 1/2	NC38	2 1/4	30.16	4 7/8	2 3/8	22,900	11,450 – 13,740	237,600	Standard	Spiral
Spec Sheet	3 1/2	NC38	2 1/4	25.36	4 7/8	2 5/16	22,900	11,450 – 13,740	237,600	Standard	Tri-Spiral
Spec Sheet	3 1/2	NC38	2 1/4	26.55	5	2 1/4	24,800	12,400 – 14,900	237,600	Standard	Conventional
Spec Sheet	3 1/2	HT38	2 1/4	25.36	4 7/8	2 1/4	34,200	12,900 – 20,500	237,600	Standard	Tri-Spiral
Spec Sheet	3 1/2	HT38	2 1/4	30.39	4 7/8	2 9/16	29,400	12,200 – 17,700	237,600	Standard	Spiral
Spec Sheet	4	XT38	2 9/16	29.38	4 3/4	2 9/16	31,300	11,500 – 18,800	407,600	Standard	Tri-Spiral
Spec Sheet	4	TT390	2 9/16	28.81	4 7/8	2 9/16	46,100	23,000 – 32,300	407,502	Standard	Conventional
Spec Sheet	4	XT39	2 9/16	28.24	4 7/8	2 9/16	37,000	12,400 – 22,200	407,600	Standard	Conventional
Spec Sheet	4	XT39	2 9/16	29.99	4 7/8	2 9/16	37,000	12,400 – 22,200	407,600	Standard	Tri-Spiral
Spec Sheet	4	XT39	2 9/16	29.82	4 7/8	2 9/16	33,900	11,400 – 20,300	815,200	Integral	Tri-Spiral
Spec Sheet	4	XT39	2 9/16	29.26	4 7/8	2 9/16	33,900	11,400 – 20,300	815,200	Integral	Spiral
Spec Sheet	4	XTM39	2 9/16	28.69	5	2 9/16	31,000	15,500 – 18,600	667,000	XD-90	Conventional
Spec Sheet	4	XT39	2 9/16	28.69	5	2 9/16	40,800	14,700 – 24,500	407,600	Standard	Spiral
Spec Sheet	4	HT40	2 9/16	28.69	5	2 9/16	28,500	10,700 – 17,100	815,200	Integral	Conventional
Spec Sheet	4	HT40	2 9/16	30.48	5	2 9/16	28,500	10,700 – 17,100	815,200	Integral	Tri-Spiral
Spec Sheet	4	WT38	2 9/16	28.69	5	2 9/16	43,300	9,000 – 21,000 – 31,500	815,200	Integral	Spiral
Spec Sheet	4	XTM39	2 9/16	28.69	5	2 9/16	37,200	18,600 – 22,300	407,600	Standard	Spiral
Spec Sheet	4	XTM39	2 9/16	28.69	5	2 9/16	34,100	17,000 – 20,400	815,200	Integral	Conventional
Spec Sheet	4 1/2	GPDS40	2 3/4	38.03	5 1/4	2 3/4	33,300	16,700 – 20,000	548,100	Standard	Conventional
Spec Sheet	4 1/2	Delta425	2 3/4	37.23	5 1/4	2 3/4	51,400	25,700 – 36,000	548,060	Standard	Conventional
Spec Sheet	4 1/2	Delta 425	2 3/4	37.50	5 3/8	2 3/4	56,000	28,000 – 39,200	548,060	Standard	Conventional
Spec Sheet	4 1/2	XTM40	2 3/4	36.85	5 1/4	2 3/4	38,200	19,100 – 22,900	1,096,100	Integral	Conventional
Spec Sheet	4 1/2	TT-485	2 3/4	43.31	6 1/4	2 3/4	108,000	49,800 – 64,786	548,100	Standard	Tri-Spiral
Spec Sheet	4 1/2	XTM40	2 11/16	39.53	5 1/4	2 11/16	40,000	20,000 – 24,000	1,125,500	Integral	Tri-Spiral
Spec Sheet	5	XT50	3	51.66	6 1/2	3	98,300	31,000 – 59,000	691,200	Standard	Tri-Spiral
Spec Sheet	5	NC50 (4-1/2″ IF)	3	57.93	6 1/2	3	52,000	26,000 – 31,200	1,382,300	Integral	Spiral
Spec Sheet	5	XT50	3	49.77	6 5/8	3	105,300	35,100 – 63,200	691,200	Standard	Conventional
Spec Sheet	5	NC50 (4-1/2″ IF)	3	57.93	6 5/8	3	53,000	26,500 – 27,500	1,382,300	Integral	Spiral
Spec Sheet	5	NC50 (4-1/2″ IF)	3	49.77	6 5/8	3 1/16	56,500	28,250 – 33,900	691,200	Standard	Conventional
Spec Sheet	5	NC50 (4-1/2″ IF)	3	58.55	6 5/8	3 1/16	56,500	28,250 – 33,900	691,200	Standard	Spiral
Spec Sheet	5	NC50 (4-1/2″ IF)	3	52.34	6 5/8	3 1/16	56,300	28,150 – 33,700	691,200	Standard	Tri-Spiral
Spec Sheet	5 1/2	XT54	3 1/4	57.57	6 5/8	3 1/4	93,200	26,600 – 55,900	1,700,900	Integral	Conventional
Spec Sheet	5 1/2	TT550	3 1/4	57.57	6 5/8	3 1/4	850,400	56,800 – 68,200	850,400	Standard	Conventional
Spec Sheet	5 1/2	Delta 544	3 1/4	58.41	6 5/8	3 1/4	86,600	43,300 – 52,000	850,438	Standard	Conventional
Spec Sheet	5 1/2	HT55	3 1/4	60.13	7	4	77,200	33,600 – 46,300	850,400	Standard	Conventional
Spec Sheet	5 1/2	XT57	3 1/4	59.51	7	4	106,200	36,400 – 63,700	850,400	Standard	Conventional
Spec Sheet	5 1/2	HT55	3 1/4	60.87	7 1/8	3 5/16	105,700	40,600 – 63,400	850,400	Standard	Conventional
Spec Sheet	5 1/2	HT55	3 1/4	60.87	7 1/4	3 1/4	105,500	41,600 – 63,500	1,700,900	Integral	Conventional
Spec Sheet	5 1/2	5 1/2″ FH	3 1/4	62.27	7 1/2	3 5/16	78,500	39,250 – 47,100	850,400	Standard	Conventional
Spec Sheet	5 1/2	5 1/2″ FH DSTJ	3 1/2	55.62	7	3 1/2	85,200	30,100 – 44,900	1,555,100	Integral	Conventional
Spec Sheet	5 1/2	HT55	4	55.24	7 1/8	4	77,500	33,800 – 46,500	615,600	Standard	Spiral
Spec Sheet	5 7/8	XT57	4	55.14	7	4	106,200	36,400 – 63,700	799,800	Standard	Conventional
Spec Sheet	5 7/8	XT57	4	57.42	7	4	106,200	36,400 – 63,700	799,800	Standard	Tri-Spiral
Spec Sheet	5 7/8	TT-585	4	56.93	7	4	116,500	58,300 – 69,900	799,800	Standard	Tri-Spiral
Spec Sheet	6 5/8	6 5/8″ FH	4 1/2	73.59	8 1/2	4 1/2	75,000	37,500 – 45,000	1,021,600	Standard	Conventional

Heavy Weight Drill Pipe Specs Selection And Design

Field tests indicated that fatigue build up in the Drill Pipe in the transition zone is related to the relative stiffness of the Drill Collars and the adjacent Drill Pipe. The stiffness ratio of two sections of pipe in the drill string is expressed by the equation,

The field tests showed that the higher the stiffness ratio at the transition zone the greater the fatigue build up. Criteria for permissible stiffness ratio varies between different operators and areas. The following maximums are typical:

• For shallow or routine drilling or low failure rate experience, keep stiffness ratio below 5.5.
• For more severe drilling or for significant failure rate experience, keep SR below 3.5.

In order to reduce the stiffness ratio and increase service life of the drill pipe, heavy weight drill pipe having the same OD as the drill pipe and a wall thickness of up to 1 in and weight up to 78 lb/ft is used between the drill pipe and the drill collars. The number of joints used varies between 15 to 21 joints.

Use of HWDP offers the following advantages

• Reduces drilling cost (check also drilling cost per foot) by eliminating Drill Pipe failures in the transition zone.
• Significantly increases performance of small rigs through the ease of handling.
• Provides substantial savings in directional drilling by replacing most of the Drill Collars string, reducing down hole drilling Torque and Drag.
• Reduces tendency to become Deferentially stuck. This is due to the fact that large diameters are easier to stick than small diameters.

Heavy weight drill pipe normally has the same external dimensions as the regular Drill Pipe. In some types of Heavy Weight Drill Pipes, the tool joints are longer and, in some types, an extra mock tool joint is located in the center of the joint as shown in the below drawing.

Heavy weight drill pipe specs vary for different manufacturers. Typical dimensions are shown in below table