PropertyValue
http://www.w3.org/1999/02/22-rdf-syntax-ns#type
http://www.w3.org/ns/prov#value
  • Produced water may also include man-made contaminants, such as drilling mud, ???frac flow back water??? that includes spent fracturing fluids including polymers and inorganic cross-linking agents, polymer breaking agents, friction reduction chemicals, and artificial lubricants.
http://www.w3.org/ns/prov#wasQuotedFrom
  • google.es