基于气井产水量预测的泡排剂加注制度优化

Optimization of Foam Drainage Agent Injection System Based on Water Production Prediction of Gas Well

针对目前气井泡排剂加注制度仅凭经验制定,无法满足现场产出水的动态变化,提出基于时间序列模型的天然气井产水量预测方法,根据产水量预测结果调整泡排剂加注制度,指导现场生产。以苏南气田两口产水气井为研究对象,采用简单移动平均法、加权移动平均法、趋势移动平均法和指数平滑法进行产水量预测,依据预测数据和实际观察值的均方根误差(RMSE)、期望值绝对偏差(EVAD)和总产水量相对误差的对比,优选气井产水量预测方法,并根据预测结果优化泡排剂加注制度,并进行现场试验。结果表明:趋势移动平均法不适合气井的日产水量预测,简单移动平均法、加权移动平均法和指数平滑法能够满足气井现场产出水预测要求。对于产水量波动较大的气井,也可采用上述三种预测方法,但在预测过程中需要注意基础数据的选取。根据指数平滑法预测的气井产水量结果优化泡排剂加注制度能够显著提高气井产量,1#气井和2#气井的产气量分别提高了26.37%和28.03%。

In view of the fact that the current gas well foaming agent injection system was formulated only by experience and can not meet the dynamic changes of on-site produced water,a water production prediction method of natural gas wells based on time series model was proposed.The foaming agent injection system was adjusted according to the water production prediction results to guide on-site production.Taking two water producing gas wells in Sunan gas field as the research object,the water production of gas wells was predicted by using simple moving average method,weighted moving average method,trend moving average method and exponential smoothing method.According to the comparison of root mean square error(RMSE),absolute deviation of expected value(EVAD)and relative error of total water production between predicted data and actual observation value,the water production prediction method of gas wells was optimized.According to the prediction results,the filling system of foam discharge agent was optimized,and the field test was carried out.The results showed that the trend moving average method was not suitable for the prediction of daily water production of gas wells,and the simple moving average method,weighted moving average method and exponential smoothing method could meet the requirements of field water production prediction of gas wells.For gas wells with large fluctuations in water production,the above three prediction methods could also be used,but attention should be paid to the selection of basic data in the prediction process.According to the water production of gas wells predicted by exponential smoothing method,optimizing the foam drainage agent injection system could significantly improve the production of gas wells,and the gas production of 1#gas wells and 2#gas wells were increased by 26.37%and 28.03%respectively.