About: http://webisa.webdatacommons.org/15089574

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	In order to perform various cementing operations such as the above cementing operation, it is usually necessary to employ a cement head on top of the well casing.
http://www.w3.org/ns/prov#wasQuotedFrom	google.fr