Definitions for "Annular Space"
("annulus") - the space between the well casing and the borehole wall.
The space found between the wall of the inner fluid carrying/holding container and the outer insulating shell. In cryogenic systems, the annular space is typically filled with insulation material, and then the gas is evacuated.
The space between a well's casing and the wall of the borehole.
Keywords:  gap, hole, outside, edge, penetrating
the gap between the penetrating item and the outside edge of the hole