Tubing Pup Joint

What is a tubing pup joint?

In the oil and gas drilling industry, tubing pup joints are specialized short pieces of tubing used to adjust the length of tubing strings and are crucial components for well completion. These nipples allow drillers to replace drill pipe without having to pull the entire pipe out of the well. This is a common practice, especially when drilling deep wells. Therefore, tubing pup joints are one of the most critical joints in any well. Their core function is to precisely match the desired well depth while providing flexibility during on-site installation.

Tubing pup joint is 6.10 m shorter than the tubing length in API 5CT.

Core Functions:
Compensate for cumulative tubing string length errors (precise adjustment within ±1m); 

Strengthen specific locations (such as near packers and safety valves); 

Partially replace damaged tubing sections to avoid pulling out the entire tubing.

Typical Scenarios:
Aligning the pay zone during well completion; 

Controlling staged fracturing spacing in horizontal wells; 

Repairing corroded sections in older wells.

Tubing pup joint specifications:

API 5CT Tubing & Tubing pup joint with connector

Standard: API 5CT, API 5B

Specifications: 2-3/8″, 2-7/8″, 3-1/2″, 4-1/2″
Steel grade: J55, K55, N80, L80, P110

Length: 2FT-20FT 

Buckle Types: Includes NUE (normal buckle), EUE (enhanced buckle), BTC (special buckle), and more to meet the needs of various downhole operating conditions.

Tubing/tubing pup joint packaging: bundled and covered with plastic sheeting.

Uses: Used for wellhead length adjustment.

Typical Structure:
Made of thick-walled seamless pipe with couplings at both ends, sealed by threads or special buckles. Some models, such as the API 5B P110 NU thickened tubing nipple, feature wall thickness and processing optimized for high-pressure environments.

Tubing pup joint are divided into five types according to their appearance:

(A) Thickening without thickening short section - the same specifications at both ends, one end of the tubing short pipe connected to thickening tubing, the other end is not connected to the thickening of the tubing or special thread tubing;
(B) Thicker outer diameter tapered section - different specifications at both ends, one end of tubing short pipe connected to a large outer thick tubing, the other end connected to a small size tubing;

(C) Thicker outer thickening short section - the same specifications at both ends, one end of the tubing short pipe connected to the outer thick tubing, the other end connected to the same specifications thick tubing;
(D) The same diameter short section - the same specifications at both ends, one end of the tubing short joints without thickening tubing or special threaded tubing, the other end is not connected to thickening tubing or special threaded tubing;

(E) Not thickened tapered ends - different specifications at both ends, one end of the tubing nipple is connected to a large gauge non-thickened tubing and the other end is connected to a small gauge tubing.

Technical Specifications of Tubing Pup Joint and Crossover:

Size / Thread	Grades	Length	Length	Length	Length	Length	Length
2 3/8" EUE
2 3/8" EUE	J55	2 FT	4 FT	6 FT	8 FT	10 FT	12 FT
2 3/8" EUE	L80	2 FT	4 FT	6 FT	8 FT	10 FT	12 FT
2 3/8" EUE	N80	2 FT	4 FT	6 FT	8 FT	10 FT	12 FT
2 3/8" EUE	P110	2 FT	4 FT	6 FT	8 FT	10 FT	12 FT
2 7/8" EUE
2 7/8" EUE	J55	2 FT	4 FT	6 FT	8 FT	10 FT	12 FT
2 7/8" EUE	L80	2 FT	4 FT	6 FT	8 FT	10 FT	12 FT
2 7/8" EUE	N80	2 FT	4 FT	6 FT	8 FT	10 FT	12 FT
2 7/8" EUE	P110	2 FT	4 FT	6 FT	8 FT	10 FT	12 FT
3 1/2" EUE
3 1/2" EUE	J55	2 FT	4 FT	6 FT	8 FT	10 FT	12 FT
2 7/8" EUE	L80	2 FT	4 FT	6 FT	8 FT	10 FT	12 FT
2 7/8" EUE	N80	2 FT	4 FT	6 FT	8 FT	10 FT	12 FT
2 7/8" EUE	P110	2 FT	4 FT	6 FT	8 FT	10 FT	12 FT
4 1/2" EUE
4 1/2" EUE	J55	2 FT	4 FT	6 FT	8 FT	10 FT	12 FT
4 1/2" EUE	L80	2 FT	4 FT	6 FT	8 FT	10 FT	12 FT
4 1/2" EUE	N80	2 FT	4 FT	6 FT	8 FT	10 FT	12 FT
4 1/2" EUE	P110	2 FT	4 FT	6 FT	8 FT	10 FT	12 FT
2 3/8" NUE
2 3/8" NUE	J55	2 FT	4 FT	6 FT	8 FT	10 FT	12 FT
2 3/8" NUE	L80	2 FT	4 FT	6 FT	8 FT	10 FT	12 FT
2 3/8" NUE	N80	2 FT	4 FT	6 FT	8 FT	10 FT	12 FT
2 3/8" NUE	P110	2 FT	4 FT	6 FT	8 FT	10 FT	12 FT
2 7/8" NUE
2 7/8" NUE	J55	2 FT	4 FT	6 FT	8 FT	10 FT	12 FT
2 7/8" NUE	L80	2 FT	4 FT	6 FT	8 FT	10 FT	12 FT
2 7/8" NUE	N80	2 FT	4 FT	6 FT	8 FT	10 FT	12 FT
2 7/8" NUE	P110	2 FT	4 FT	6 FT	8 FT	10 FT	12 FT
3 1/2" NUE
3 1/2" NUE	J55	2 FT	4 FT	6 FT	8 FT	10 FT	12 FT
3 1/2" NUE	L80	2 FT	4 FT	6 FT	8 FT	10 FT	12 FT
3 1/2" NUE	N80	2 FT	4 FT	6 FT	8 FT	10 FT	12 FT
3 1/2" NUE	P110	2 FT	4 FT	6 FT	8 FT	10 FT	12 FT
4 1/2" NUE
4 1/2" NUE	J55	2 FT	4 FT	6 FT	8 FT	10 FT	12 FT
4 1/2" NUE	L80	2 FT	4 FT	6 FT	8 FT	10 FT	12 FT
4 1/2" NUE	N80	2 FT	4 FT	6 FT	8 FT	10 FT	12 FT
4 1/2" NUE	P110	2 FT	4 FT	6 FT	8 FT	10 FT	12 FT

Tubing pup joint according to the function is divided into three types:

(A) Male and female short sections: the specifications at both ends are external thread, thickening without thickening plus short section, thickening variable short section, plus thickness thickening short section, the same diameter short section and not any of a variety of thick tapered joints. 

(B) Conversion of short section: one end of the male thread, the other end of the female thread, the thickening of the thickening of the outer short section, the outer thick thickening short section, And not thickening adjustable short joints screwed on the coupling. 

(C) Adjust the short section: indefinite length, according to the engineering needs of design, one end of the external thread, the other end of the internal thread thickening in the thickening of the short section, thickening variable short section, plus thickening plus Thick and short sections, the same diameter short section and non-thickening on the short section screwed on the coupling.

Tubing pup joint testing and inspection
According to API 5CT, API 5B or customer-specified standards, a strict inspection and testing system is adopted before shipment, including appearance inspection, dimensional inspection, chemical composition inspection, performance test, strength test, tensile test, hardness test, non-destructive testing, hydrostatic test, etc.

Tubing pup joint performance characteristics:
Mechanical Strength: The pup joint body is engineered to exhibit excellent mechanical strength and overall performance, ensuring reliability under demanding conditions.
Precision Machining: The threads are cut using CNC machines, which guarantees high precision and contributes to an extended lifespan of the joint.
Wear Resistance: The application of phosphate coating or copper plating enhances the joint’s wear resistance, providing durability in various environments.

Read more: API Coupling and Threads for Tubing & Casing Pipe Connection