nounWord forms: pluralˈannuˌli (ˈænjuˌlaɪ; ˈænjəˌlaɪ) or ˈannuluses
any ring or ringlike part, mark, etc.
Word origin
L annulus, for anulus: see annular
annulus in the Oil and Gas Industry
(ænyələs)
Word forms: (plural) annuluses
noun
(Extractive engineering: Field development, Drilling)
An annulus is the space between two concentric objects (= objects of the same shape in whicha larger one surrounds a smaller one), for example, between the wellbore and casing.
Cement casing involves filling the annulus between the casing and the wall of the hole with cement to support the casing andto prevent fluid migration between permeable zones.
Perforation provides holes in the casing so that materials may be introduced intothe annulus between the casing and the wall of the borehole.
An annulus is the space between two concentric objects, for example, between the wellbore andcasing.