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

摘要： 针对松南气田气井井筒结垢问题, 对垢进行成分分析, 并在室内条件下进行结垢实验研究, 同时利用 饱和指数法对气井结垢进行结垢趋势预测研究。结果表明, 松南气井井筒垢物主要为碳酸钙, 在一定的井筒产出水 中, 其他条件不变的情况下, 结垢质量随温度的升高而增大, 随压力的升高而减小。结合压井液和地层水的配伍性 实验可以得出: 结垢的主要原因是C a C l 2 型压井液与地层水的不配伍性, 地层水进入井筒后压力下降导致C a CO3 溶 解度下降产生沉淀结垢; 利用 O d d o - T o m o s o n饱和指数法对C a CO3 结垢趋势的理论预测结果与实际测量结果一致。

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