Characteristics of backwash recovery water from different oilfield filters for water treatment

An investigation on the quality difference of backwash recovery water (BRW) from three filters in NH, TY and TL in an oilfield was carried out, and the influence of recycling BRW on the treatment efficiency of filters was discussed as well. The results show that in spite of different filter media, backwash model and water properties, filters in NH, TY, and TL gives high recycling rates of suspended solids of about 40% and a relatively low treatment efficiency for suspended solids. Filters with external scrubbing backwash process and used to treatment of polymer-containing produced water in TL gives a highest recycling rate of 52% for oil, while other filters give a relatively high and acceptable treatment efficiency for oil.