Assertion: natural gas | /r/HasProperty | stored aquifer
Facets:
value: underground
type: LOCATION
value: in salt caverns
type: LOCATION
value: usually
type: TEMPORAL
value: most commonly
type: DEGREE
Source sentences:
text: Natural gas is most commonly stored underground and under pressure in three types of facilities: depleted oil and/or natural gas reservoirs, aquifers and salt caverns.
text: Natural gas is usually stored underground in formations such as empty gas reservoirs; in aquifers, or underground rock formations that hold water; and in salt caverns.