Research On Optimal Control Method Of Oil Well Based On Working Fluid Level

With most oil fields in our country come into a middle period at present, the management mode in early age which was extensive and based on manual production control limits the progress seriously. Universally, the management mode in our oil wells is based on manual regulation and non-optimized production. Particularly, the economic downturn in the world and the low oil price also impacts the old oil wells in our country. So the oil wells in our country need delicacy management for the oil production and optimizing in oil well control units in to improve economic returns in oil well fields. In this paper, based on the optimal control of the working fluid level of the oil well, a measurement for the working fluid level and a research about the control method are presented in this paper in allusion to sucker rod pump production system which most oil wells are use.At first, the meanings of the proper working fluid level to oil well’s optimizing operation and an analysis about the operation law of both the under well and on surface of the sucker rod pump production system are presented.Secondly, using the digital measurement and control platform of the oil field, based on the measurement of the indicator diagram method, on-site verification is realized, which method are:(1) By collecting the data of the ground operation law with sensors, we got the ground indicator diagram. (2) After noise suppression and digital-to-analogue conversion, we got the under well pump feature diagram. Use convex hull algorithm to do smoothing process for pump indicator diagram, to calculate its eigenvalue, and by calculating the max curvature in this diagram, we can have the load value of the oil well pump. (3) Use pressure gradient and the load value of the oil well pump to calculate the working fluid level of the oil well, and revise the data to improve the accuracy of the measurement.Finally, a working fluid level controller is designed to adjust the speed of the oil pumping unit in real time. The steps are:(1) Build the working fluid level switching system model based on pressure gradient relationship. (2) Analyze the stability of the working fluid level switching system. (3) Design the working fluid level switching system controller. (4) Collect the oil well data and set the parameters of the controller to verify the simulation of the controller.In this paper, by measuring the working fluid level and researching and verifying the control method, it shows that this working fluid level control method plays an important role in the oil field optimizing, which optimizes the oil production controller unit effectively, and this method presented in this paper presents a recommendable solution for oil well’s managers and researchers.