Definition(s)
Structural Pipe (or casing)
Pipe utilized to facilitate the drilling of a well, but not intended for pressure containment after the well has been drilled. Supports unconsolidated sediments and provides hole stability for initial drilling operations, axial support for casing loads and bending loads from the wellhead. See also definition for drive/jet pipe.
Source: API STD 65 – Part 2, Isolating Potential Flow Zones During Well Construction, Upstream Segment, Second Edition, December 2010. Global Standards
Structural
Large OD casing; jetted in or drilled and cemented. Normal clearance casing OD in.: 30. Tight clearance casing OD in.: 36. NOTE These are examples only. Each well can have variations in number of casing strings and sizes. Naming conventions can vary. The heavy-wall surface casing designs may allow 13 5/8 in. to be run as a liner and not tied back.
Source: API RP 96, Deepwater Well Design and Construction, First Edition, March 2013. Global Standards