Real-time Diagnosis And Optimization Of Rod Pumping System On The Steam Huff And Puff Well

Steam soak operations is the main methods of developing the heavy oil reservoirs.There are large changes of the reservoir pressure,the water content ratio and the reservoir temperature in a cycle.As a result,the standard,such as the balance,the safety of sucker-rod string and pump efficiency,also have a big change in the cycle.Because the real-time analysis and optimization system,by now,is not existed,some measures can not been carried out on time to prevent pump problems,increase run lifes,and reduce workover costs based on the real-time change of the production parameters.The study of real-time diagnosis and optimization of rod pumping system on the steam huff and puff well has be done based on the real-time monitoring parameters,such as the production,the bottom hole flowing pressure,the temperature of production liquid,the water content ratio,the electric power curve and surface dynamometer cards.The calculation model of real-time production,bottom hole flowing pressure,reservoirs temperature and water content ratio has bean established and perfected based on real-time monitoring parameters.Based on the real-time estimation parameters,the flow regimes modle of steamsoaking wells has been fitted.The balance calculation model has been derived and perfected,based on the real-time electric power curve and surface dynamometer cards.The balance adjustment model also has been derived and built,with the energy balance equation,seeing the ground pumping system as a whole.Using the characteristics of surface dynamometer cards under incomplete pump conditions,the fluid viscosity calculation model has been corrected.The safety of the sucker rod is analyzed by the modified Goodman diagram method,and the historical stress range ritio of the sucker rod is linearly fitted by the least squares method to forecast the trend of the condition of the sucker rod safety.Based on the calculation model of fluid production and the definition of pump efficiency,the model of pump efficiency has been established and derived.Statistical analysis was carried out to analyze the pump efficiency at the end of the steamsoaking cycle.The average value of pump efficiency is used as the warning limit of pump efficiency.The historical pump efficiency data in the steamsoaking cycle are linearly fitted using the least squares method to make predictive and early warning analysis of pump change trend.Respectively,the maximum amount of liquid production and pump efficiency has been defined as the optimization target.Based on the established flow regimes modle of steamsoaking wells,the calculation model of pump rod safety analysis,the model of pump efficiency,using the exhaustive method for different stroke,red times and doping ratio of thin oil,the production,sucker rod safety and pump efficiency are calculated to reach the best product parameters adjustment program.The software of Real-time Diagnosis and Optimization of Rod Pumping System on the Steam Huff and Puff Well is done.The results show that the theory and method established in this paper are scientific and reasonable,and can provide guidance for on-site production and management.The liquid production modle based on the real-time surface dynamometer cards is carried out on 10 wells,its average relative error is 5.68%.The liquid levels modle based on the real-time surface dynamometer cards is carried out on 10 wells,its average relative error is 10.48%.The correction modle of steamsoaking-wells flow regimes is carried out on 9 wells,and the average relative error of the calculated production is 11.34%.The down hole temperature modle is carried on 19 wells.The relative error of the temperature is 10.72%.The down hole water content ratio modle ia carried on 18 wells.The relative error of the down hole water content ratio is 16.32%.The balance adjustment calculation of the pumping unit was carried out on 5 wells,its the relative error is 8.80%.The real-time pump efficiency calculation model is carried out on 10 wells,its relative error is 5.68%.The optimization and adjustment model of production parameters is carried out.The results show that production of liquid can be increased by 4.51m~3/d;The pump efficiency can be increased by 0.289,the optimization result is operability,which provides theoretical support for the optimization of production parameters in oil field.