Production tubing

Production tubing protects wellbore casing from wear, tear, corrosion, and deposition of by-products, such as sand / silt, paraffins, and asphaltenes.

It is usually between five and ten centimeters in diameter and is held inside the casing through the use of expandable packing devices.

Purpose and design of production tubing is to enable quick, efficient, and safe installation, removal and re-installation.

Tubing is a smaller diameter pipe that is run inside of the production casing.

A packer is an elastomer cylinder that forms a pressure seal between the tubing and the casing.

Probably, this well required a high mud weight at the bottom of the hole and cementing the 7+5⁄8 in (190 mm) casing at TD would have resulted in too much pressure and lost circulation.