Water treatment process for oilfield produced water

摘要

The invention relates to a method and system for treating an aqueous liquid containing dissolvedminerals and dissolved hydrocarbons. Method steps and apparatus for treatinga waste water feed stream are disclosed which utilize a warm lime softening system(60) in fluid communication with the waste water feed stream (2), wherein sludgefrom the warm lime softening system is recycled to improve lime utilization andenhance silica and boron removal without the addition of an external source ofmagnesium. In addition, a microf iltration system (140) and/or an air stripper(220) system may be used in fluid communication with at least one reverse osmosissystem (200,240) to produce a treatment water that meets state and federal guidelinesfor surface discharge.