What tool is a permanent attachment to the side of the completion that allows the connection of valves and gauges?

• A. Mandrels
• B. Bridge plugs
• C. Landing collars
• D. Subsurface safety valves

Answer: (A)

In completions, a permanent side attachment that lets you hook up valves and gauges is a mandrel, specifically a side-pocket mandrel. This device is run with and fixed to the completion string, creating a fixed side port to connect downhole instrumentation without interfering with the main bore. It provides a reliable interface for downhole equipment, so gauges, valves, and related accessories can be installed and accessed as needed while the production flow continues through the central bore. Other options serve different roles—bridge plugs isolate zones and are retrievable, landing collars provide a landing point for tools within the bore, and subsurface safety valves control the bore from inside the string—whereas the mandrel is the one designed to remain as a permanent side attachment for these connections.