Scale Determination And Anti-scaling Research Of High Temperature And High Pressure Injection Well In G Oilfield

In the development of oilfield water injection,it is troubled by scaling damage to varying degrees.Especially in the middle and late stages of development,the required water injection volume has gradually increased,and the problem of scaling in injection wells has become more common and serious.Oilfields damage caused by oil field water scaling,oil and water wells and ground pipelines obstruction,equipment corrosion is intensified,and premature occurrence of oil wells,equipment scrapping and other phenomena often occur.The emergence of these problems has greatly increased the cost of oil production and seriously affected the normal production of oil fields.In order to better understand the cause of scaling in the oil field and the anti-scaling measures,the following work is carried out on the scaling of high temperature and high pressure water injection wells in G oilfields:(1)Determined the status and causes of water injecting in G oilfields,the mechanism of injecting water scaling,the mechanism of descaling and the influencing factors,combined with the water sample data of G oilfields and the actual conditions of high temperature and high pressure,the scaling sample analysis is carried out.The main fouling type of G oilfields is calcium carbonate scale.(2)Based on the scaling prediction software,the influence of various factors on the amount of calcium carbonate scale was evaluated.(3)Conducted an indoor experimental evaluation study of water injecting scale,and discussed the variation law of calcium carbonate scaling when the scale ion concentration,temperature,pressure and pH were changed under high temperature and high pressure conditions.(4)According to the actual situation of high temperature and high pressure water injection wells in G oilfields,the anti-scaling measures of G oilfields were studied,including nanofiltration water treatment anti-scaling technology,water injection scale inhibition technology and water injection descaling technology.The high-efficiency temperature and scale inhibitor is selected,and the water softening scheme of the injected water and the dewatering scheme of the injected water are proposed,in order to help the fouling control of the G oilfields.