PropertyValue
http://www.w3.org/1999/02/22-rdf-syntax-ns#type
http://www.w3.org/ns/prov#value
  • The system and method of the present invention provides is a system for drilling geopressured wells utilizing hydraulic friction on the return annulus path downhole to impose a variable back pressure upon the formation at any desired level from low head, to balanced and even to underbalanced drilling.
http://www.w3.org/ns/prov#wasQuotedFrom
  • google.com