Page 107 - Well Control for Completions and Interventions

Completion Equipment 99

Figure 3.10 Horizontal tree plug. Image courtesy of NOV Elmar.

snubbing) are needed. From the well intervention perspective, horizontal
trees have few advantages. They are, however, advantageous on wells that
are likely to require frequent recompletion (replacement of the tubing
string), the best example being wells with ESPs. ESPs fail with depressing
regularity, requiring frequent replacement. Use of a horizontal tree can
result in considerable time savings, as the tree does not have to be
removed to allow the completion to be recovered. Horizontal trees are
increasingly used on modern offshore platforms and satellite towers. The
compact nature of the tree enables designers to reduce the overall size of
the platform structure.

3.2 TUBULARS
Rig site supervisors need to have a working knowledge of the prop-
erties of oilfield tubular goods. Completion tubing is described using ter-
minology that is in widespread use amongst industry professionals. Tubing
is defined with regard to:
• size (outer diameter, OD),
• weight in pounds per linear foot (lb/ft),
• yield (usually in psi),
• grade (metallurgy).
For example, a tubing string selected for a completion might be
1
described as: 5/2v 17 lb/ft L-80 13% chrome.