PREFIX : SELECT DISTINCT ?wellbore ?total_cored_length ?strat_unit_name ?top_md ?bot_md WHERE { ?w a :Wellbore ; :name ?wellbore ; :hasTotalCoreLength ?tcl . ?tcl :valueInStandardUnit ?total_cored_length FILTER ( ?total_cored_length > 30 ) OPTIONAL { ?w :hasWellboreInterval ?strat_zone . ?strat_zone a :StratigraphicZone ; :hasUnit ?strat_unit ; :hasTopDepth ?top ; :hasBottomDepth ?bot . ?strat_unit :name ?strat_unit_name . ?top a :MeasuredDepth ; :valueInStandardUnit ?top_md . ?bot a :MeasuredDepth ; :valueInStandardUnit ?bot_md } }