What is a pup joint?

Pup joints are a type of tubular product used in oil and gas drilling and production operations. They are short lengths of pipe, usually ranging from 2 feet to 10 feet long, that are used to make up for length discrepancies when assembling longer sections of drill pipe or casing.

It gets its name from the fact that they are much shorter than the "parent" joints of drill pipe or casing that make up the majority of the string. Like a puppy is much smaller than a full grown dog, a joint is much shorter than a typical 30-40 foot length of drill pipe.

As mentioned above, it is typically quite short, ranging from just 2 feet (24 inches) up to 10 feet in length. However, there is no standard length. They are manufactured in a variety of sizes to provide the specific length required in order to make up the exact length of pipe needed for a particular application.

◆Some of the most common lengths are:

- 2 foot (24 inches)

- 3 foot (36 inches)

- 5 foot (60 inches)

- 10 foot (120 inches)

The length required will depend on the total length of the drill string or casing string being assembled and the standard lengths of the regular joints being used. Joints help drillers achieve an exact desired string length when the regular joints alone would result in a length slightly shorter than optimal.

Its weight depends on its size - length, outside diameter, and wall thickness. Small-diameter joints can weigh 100 pounds or less. Large-diameter joints used in deeper wells may weigh 2,000 pounds or more.

In general, they are manufactured from the same grade of steel pipe as standard drill pipe and casing joints. API grade pipe is the most common. The pipe is simply cut to a shorter length. Therefore, the wall thickness and material strength are the same as a regular joint.

The weight per foot of steel drill pipe and casing increases with larger pipe diameters and wall thicknesses. An approximate guide to the weight per foot of common oilfield pipe sizes is:

- 2-3/8" O.D. drill pipe - around 9 lbs/ft

- 4-1⁄2" O.D. drill pipe - around 19 lbs/ft

- 5-1⁄2" O.D. casing - around 29 lbs/ft

- 7" O.D. casing - around 49 lbs/ft

So a 5-foot joint of 5-1⁄2" casing would weigh around 145 pounds (5 x 29 lbs/ft). While a 10-foot length of the same size would be double the weight at around 290 pounds.

Its weight needs to be taken into account when designing drill strings and casing strings to ensure the total weight does not exceed crane lifting capacities and prevent excess stress on pipe connections.

Joints are available in a wide range of outer diameters and wall thicknesses to match the specifications of standard drill pipe and casing sizes. Some of the most common sizes are:

The drill pipe and casing used in a given well will dictate the outer diameter and grade required for any joints. Shorter custom lengths can be manufactured as needed for specific applications. Its ends are threaded to allow connection to regular joints.

Pup joints are short sections of tubular steel pipe used in the oil industry to achieve precise lengths when making up drill strings and casing strings. Need custom joints for your next drilling or completion job? Our products are manufactured to the highest standards and are available in a full range of sizes to match your specifications. Whether you need short 2 ft joints or longer 10 ft lengths, we can provide the exact lengths you need to fine-tune your pipe strings, Please feel free to contact us at info@vigorpetroleum.com.