PropertyValue
http://www.w3.org/1999/02/22-rdf-syntax-ns#type
http://www.w3.org/ns/prov#value
  • Packers may be used to seal the annulus between a casing or a liner string and a surface exterior to the string, such as an open wellbore or a casing and often packers are actuated by hydraulic pressure which is transmitted either through the bore of the string, the annulus, or a separate line.
http://www.w3.org/ns/prov#wasQuotedFrom
  • google.com