Abstract: By introducing a case study of waste water treatment and reinjection in an oilfield,the authors discussed the installation and technology available to waste water control,and affects of changeable operational loads on sewage treating system,which in turn will make a more flexible design of oilfield waste water treatment.In order to deal with the 3 major issues related to water quality,i.e.corrosin,blockage and scale,a rational use of reagents is suggested.Additionally,the prospects of waste water control were propoed.