Pup Joints

A pup joint is a small yet essential component in the oil and gas industry. While seemingly simple, it plays a crucial role in connecting pipes and ensuring the efficiency of drilling or production operations. In this article, we will explore the purpose, types, and applications of pup joints in detail.

Pup joints are short lengths of casing and tubing, or drill pipe. Their primary function is to adjust the overall length of a pipe string to meet specific operational requirements. In drilling and well completion processes, precise pipe lengths are critical to ensuring smooth operations. Without pup joints, achieving this level of precision would be much more difficult.

Pup joints are available in standard lengths of 5, 10, 15, and 20 feet. For specialized needs, custom lengths can be manufactured upon request. They are designed to handle a minimum yield strength of 110,000 PSI, making them suitable for demanding drilling conditions.
These joints are often equipped with standard API or proprietary high-performance connections. This ensures compatibility with other components in the drill string, enhancing their adaptability.

Outside Diameter: 4 ½ inch – 13 3/8 inch

Typical Lengths: 1, 2, 3, 4, 6, 8, 10, 12 ft

No	Item	Description
1	Size	Casing pup joint Outer Diameter :4-1/2~20 (in) 114.3~508mm
		Tubing pup joint Outer Diameter:2-3/8~4-1/2(in) 60.3~114.3mm
		Casing pipe Wall Thickness : 4.2~22mm
		Tubing pipe Wall Thickness : 3.18 ~16 mm
2	Grade	J55、K55、N80-1、N80、L80-1、L80、P110
3	Casing pup joint thread	STC、LTC、BTC
4	Tubing pup joint thread	EUE、NUE
5	Length	2FT、4FT、6FT、8FT、10FT、12FT
6	Surface Treatment:	Coating
7	Standard	API Spec 5CT &5B
8	Application:	Pipe Cut into different length used for connect 2 joints of tubing or casing

SPECIFICATIONS
TUBING PUP JOINT	OD	GRADE	END TYPE	LENGTH(FT)
	2 3/8"	J/K/L/N/P	NUE/EUE	2/3/4/5/6/8/10/12
	2 7/8"	J/K/L/N/P	NUE/EUE	2/3/4/5/6/8/10/12
	3 1/2"	J/K/L/N/P	NUE/EUE	2/3/4/5/6/8/10/12
	4 1/2"	J/K/L/N/P	NUE/EUE	2/3/4/5/6/8/10/12
CASING PUP JOINT	OD	GRADE	END TYPE
	4 1/2"	J/K/L/N/P	LTC/STC/BTC
	5"	J/K/L/N/P	LTC/STC/BTC
	5 1/2"	J/K/L/N/P	LTC/STC/BTC
	6 5/8"	J/K/L/N/P	LTC/STC/BTC
	7"	J/K/L/N/P	LTC/STC/BTC
	7 5/8"	J/K/L/N/P	LTC/STC/BTC
	7 3/4"	J/K/L/N/P	LTC/STC/BTC
	8 5/8"	J/K/L/N/P	LTC/STC/BTC
	9 5/8"	J/K/L/N/P	LTC/STC/BTC
	10 3/4"	J/K/L/N/P	STC/BTC
	11 3/4"	J/K/L/N/P	STC/BTC
	13 3/8"	J/K/L/N/P	STC/BTC

The main materials of oil casing short sections are J55, K55, N80, L80, C90, T95, and P110. Hot rolling process round tube billet → heating → perforation → three-roller oblique rolling, continuous rolling or extrusion → tube removal → sizing (or reducing diameter) → cooling → straightening → water pressure test (or flaw detection) → marking → storage; cold drawing (rolling) seamless steel tube round tube billet → heating → perforation → heading → annealing → pickling → oiling (copper plating) → multi-pass cold drawing (cold rolling) → billet tube → heat treatment → straightening → water pressure test (flaw detection) → marking → storage.

Types of Pup Joints
Pup joints are categorized based on their connection types and applications. This classification helps in meeting various operational demands effectively.

Connection Types:
Threaded Pup Joints: These are further divided into two-head external thread, single-head external thread, and flathead external thread types.
Flange Pup Joints: This type connects through flanges and is often used in applications requiring bolted connections.

Usage-Based Types:
Tubing Pup Joints: Specifically designed for tubing operations, they are available in various lengths and grades.
Casing Pup Joints: These are shorter lengths of casing pipes used for precise placement in wellbores.

Connections
API Ferrule Connectors
Seamless oil pipes manufactured to API 5ct specification with quality API monogram. Available in optional diameters, lengths, weights and grades as required.

Threaded Connectors
Short seamless connections with high quality connections in API grades and special alloys. High quality ends are threaded by the manufacturer or licensee.

Sleeve Connectors
Available in any length, weight and grade as required.

Drilled Pup joint
Available in standard or special drilled distances. Each nipple has four rows of 3/8 inch holes drilled longitudinally along the pipe. Optional pattern, hole size and length as required.

Applications of Pup Joints

The primary function of pup joints is to adjust the length of tubular strings to meet specific operational requirements. This makes them ideal for:
Length Adjustments: When precise lengths are needed in a pipeline, pup joints serve as the connecting link.
Drill String Optimization: They allow for fine-tuning of drill strings, improving drilling efficiency.

Maintenance and Repair: Pup joints make it easier to replace damaged sections without altering the entire pipe string.

Comparison with Tubing

Although pup joints and tubing share similar characteristics, their primary difference lies in their length. Pup joints are shorter than Range 1 tubing while maintaining the same thread connection. This feature ensures seamless integration within the tubular string.

Advantages of Using Pup Joints

The use of pup joints offers several advantages. These include flexibility in pipe string design, reduced wastage, and enhanced operational efficiency. Operators can avoid the need for custom-length pipes, saving time and resources.