Definition(s)
Wellhead growth
Wellhead growth is the term used for axial movement of the wellhead relative to its initial position at the mudline. Wellhead growth is caused by the forces exerted on the wellhead by: thermal expansion/contraction of tubulars tied back to the wellhead and subsidence, and increasing pressure within the annuli created between the tubulars.
Source: API RP 96, Deepwater Well Design and Construction, First Edition, March 2013. Global Standards