关键词: 气井,    ,  , 碳酸钙结垢,    ,  , 原因分析,   ,  结垢趋势预测

Abstract: For the problem of scaling in producing wells in Songnan gas fields, components of the scale samples were analyzed for its, and scaling experimental research was done indoor. In addition, the trend of scaling in gas wells was predict using saturated index method. Results showed that the scale in Songnan gas wells was mainly calcium carbonate. When the well producing water was fixed, the scaling quantity arised with the temperature increasing, while reduced with the pressure rising. Considering the compatibility test, it was indicted that the mainly scaling reason was the mismatch between the CaCO₃ well killing fluid and the stratum water, which caused the decrease of pressure when the stratum water get into the wellbore. Theoretic prediction on the tendency of the scaling of CaCO₃ was made with the OddoTomoson saturating exponential method, and the result was consistent with the measurement in field.

Key words: Gas well,     ,  Calcium carbonate scale,    , Cause analysis,     , Prediction of scaling tendency