Working Condition Diagnosis For Sucker Rod Pumping Wells Using Load Reducer

With the oil field's further development,the wells which is buried deep,low energy and poor permeability are becoming more and more.Restricted by pumping rated rod load,the improvement of oil production and the applications of big pumps are effected with the depth increasing.The load reducer can reduce load,pump more deeply and save energy,so it has been more and more widely used in the oil fields.After installing a load reducer on the sucker rod for a pumping well,the dynamometer card's shape,characteristics and the accuracy of work condition diagnosis will be influenced by the change of the sucker rod's stress.To solve the problem,models are built based on the stress analysis of sucker rod,correction of the Gibbs model and the study of dynamometer card recognition and a related software is programmed.The diagnosis models which involve one or several work conditions such as normal condition,insufficient liquid supply,gas interference,parted rod,pumping bumping(upstroke),pumping bumping(downstroke),pump blocked,leaking travelling valve,leaking standing valve,leaking travelling and standing valves,sand production and pump broken are a combination of the vector method and method based on specific principles.The program ALGOR is used to test the model of figuring out the dynamometer card and the deviation is within 5.7%.The average deviation is 1.7%.The points whose deviation is less than 5% take 99.2% of all points.The related software is tested by 9 wells.The diagnosis accuracy of 100% verifies the validity and feasible of work condition diagnosis models for the sucker rod pump wells with load reducer,and it shows that the models can provide technical supports to discover,analyze and deal with oil wells failure in time and fulfill the wells efficient and stabe producing.