| Tuo three sewage treatment station is responsible for the recirculated water original treatment of more than 10 blocks of Sheng tuo oilfield such as T11 north,T7 East two,T11East two and so on.Influenced by the station corrosion and scaling,the output water quality did not meet the injection requirements.Because of the below-standard quality of source water and low effect of corrosion and scaling treatment,the downstream water quality became even worse,leading to the insufficient injection and bad water flooding efficiency.This paper first analyzes the main factors that influence the corrosion and scaling of Tuo three sewage stations,and results show that the factors leading to the high corrosion include corrosive CO2 and electrochemical corrosion of chlorine ions and bacteria（especially sulfate reducing bacteria）.At the same time,the water from Tuo two and Tuo three is not compatible,and the ion balance of mixed water is lost,which causes the scaling more serious.The pressure decreasing experimental results show that,the CaCO3 equilibrium in water changes,and the scale tendency increases obviously,with the change of pressure field in water treatment system.Based on the analysis of the main factors that influence corrosion and scaling,the tests and evaluation of inhibition,scaling and bactericidal agent are carried out,including seven kinds of corrosion inhibitor,six kinds of scale inhibitor and seven kinds of bactericide.And then,the agents performing relatively good properties are selected to test the compatibility.Based on the analysis of corrosion law in stations,the changes of different nodes corrosion rate and SRB bacteria content are studied.By optimizing the treatment point and the way of adding medicine,and the output water quality is improved obviously.Water injection situation of some the under-injected wells is improved obviously through the measures of ground line cleaning,negative pressure cleaning and N2 emptying. |
PDF Full Text Request