It's one option, used by many.

Being the space between the drill string and the borehole walls or casing, or between the casing and the borehole walls. Or in TBM tunnelling, between the TBM or the segmental lining and the rock.

1 Australian Drilling Industry Training Committee Limited, The Australian Drilling ... A special problem is leaking up the annular space around a casing. ...
books.google.com/books?isbn=1566702429...

Abstract: Recently, questions have arisen concerning the compactive nature of drilling fluids within the annular space during horizontal directional ...
www.pubs.asce.org/WWWdisplay.cgi?0521467

Reasonable limits must be placed on maximum fluid pressures in the annular space of the bore to. prevent inadvertent drilling fluid returns to the ground ...
www.nwk.usace.army.mil/local_protection/pdf/directdrill.pdf