Besides the common characteristics of normal produced water, the heavy oil produced water also has some other ones of high temperature, high salinity and high suspend solid content, which make it difficult to be treated. The waste water treatment and reuse in boiler technology developed by our corp., has successively solved this problem and has achieved the goal of heavy oil waste water harmless and resources re-use. This technology also helps to save a lot of clear water and recover some energy from the waste water, which was rewarded as second prize of National scientific and technological progress.

The technology of heavy oil produced water reuse in the boiler after treatment has adopted four critical technology and equipments, including air floatation ,fine filtration softening and silicon removal ,which successively recover the residual oil in water and remove the hardness, suspended solids and silicon dioxide to a certain extend to meet the water quality required by the steam generators.

All of these totally meet the requirements stipulated in “the design specifications of feed water treatment of heavy oil produced water for steam generators” SY/T0027-2007 and “Water quality index and water quality testing methods of heavy oil produced water reused in steam generators” Q/SY LH0233-2007. Among which ,air floatation unit uses high efficient air floatation technology to control the suspend solids and oil cut below 20mg/L and 10mg/L separately; filtration unit uses super fine filtration medium and technology to control suspend solids below 2mg/l, softing unit controls hardness below 0.1mg/l and silicon removal unit controls SiO 2 below 100mg/l..

This technology has been successfully used in liaohe oilfield and shengli oilfield .Only liaohe oilfield itself built 5 heavy oil waste water treatment stations with treating ability about 5000m³ /d and have gained significant economical benefits. Taking lengjia wastewater treatment plant of liaohe oilfield as example ,it's designed treating ability of produced water is 15000 m³ /d, 8000 m³ wastewater after treatment is reused to thermal generators and 7000 m³ is re-injected in operation. This plant was put into operation in December 2006,and created a precedent for the domestic petroleum & petro-chemical industries. These are three advantages of heavy oil wastewater reuse: recover the hear energy, reduce the clear water consumption and amount of useless re-injection . heavy oil wastewater temperature is up to 70~ 75 ℃ ,and reuse in steam generators after treatment can save the fuel cost of more than 10million RMB, and clear water of 3 million tones, meanwhile about 100 million RMB have been recovered from the oil collected in the wastewater annually.