Which term describes a short section of casing or tubing used as a depth identifier?

Which term describes a short section of casing or tubing used as a depth identifier?

• A. Pup joint
• B. Nipple
• C. Joint of tubing
• D. Wellhead spool

Answer: (A)

A pup joint is a short section of casing or tubing that provides a defined, measurable length along the string, acting as a depth marker. When assembling a wellbore string, you need precise control of where tools and completions are placed, and pup joints give you a fixed reference point without altering the overall string length. They’re shorter than standard joints and are chosen to reach a specific depth or to fine-tune the depth of the assembly, allowing you confirm the exact depth at which components are set or tested. A nipple is just a threaded connector, not a depth reference. A joint of tubing is a normal-length piece with no special depth-marker purpose. A wellhead spool is surface equipment, not part of the downhole string used for marking depth.

A pup joint is a short section of casing or tubing that provides a defined, measurable length along the string, acting as a depth marker. When assembling a wellbore string, you need precise control of where tools and completions are placed, and pup joints give you a fixed reference point without altering the overall string length. They’re shorter than standard joints and are chosen to reach a specific depth or to fine-tune the depth of the assembly, allowing you confirm the exact depth at which components are set or tested. A nipple is just a threaded connector, not a depth reference. A joint of tubing is a normal-length piece with no special depth-marker purpose. A wellhead spool is surface equipment, not part of the downhole string used for marking depth.