Study On Intelligent Diagnosis Of Well Paraffin Deposit And Technique For Electric Paraffin-removal

In the world the oil is the major product of energy and the energy consumption ratio of oil is very high in many countries, so the oil production is very important to every country. During the production process of crude oil, the paraffin deposit appears basically pumping equipment and oil transfer equipment in all of oil-production countries. When the paraffin deposit occurs the pumping equipment, the problem will cause decreasing of the pumping unit load, and even causing some accidents, such as paraffin stuck, which affect the safety and sequence of normal production. The paraffin deposition on oil transfer equipment leads to the reduction of oil flow rate, diminish the diameter of pipeline, especially paraffin blockage. The oil well production efficiency and economic benefits will be affected by the paraffin deposit, how to accurately and quickly diagnose the paraffin problem of the oil well becomes a prospective research direction in the oil field. According to the paraffin deposit problem, this article mainly consists of four parts from the well load signal parameters in the extraction and display, the mathematical model of pumping well, the diagnose method research of paraffin deposit and application of electric paraffin-removal technology, conducting a comprehensive exploration. The main research results and conclusions are as follows:First, the indicator diagram as an important basic judgment of oil well production status, and also as the substantial technical data about oil well malfunction, the signal measurement and drawing will directly affect the accuracy of malfunction diagnosis. Firstly, the article introduces the basic theory of pumping system and the concepts of indicator diagram, the CSF-3GB load sensor is used to measure and display the load parameters of pumping well, including the sensor signal conversion, regulator circuit, A/D converter and the design of data processing system.Second, after completing the indicator diagram extraction of load parameters, then the mathematical model for sucker rod pumping system is established. According to the mechanical and physical relation of pumping system, we will get the conditions about boundary and initial and continuity conditions, using the Fourier transform method and Gibbs wave equation solving, eventually the ground load function and displacement function is converted the downhole pump load function and displacement function.Third, through analyzing the indicator diagram, the malfunction method of the pumping system will be diagnosed, the paraffin problem diagnosis is also based on the characteristic parameters by analyzing the indicator diagram. From Liao He oilfield 36 indicator diagrams represent different working conditions. First of all, using the theory of mathematical morphology to pretreatment of actual measured indicator diagram, removing useless information, reserving the diagnosis characteristic of shape. Then the seven moment as the characteristic parameters of the indicator diagram to establish the diagnosis database. Finally using the SVM theory to complete the diagnosis simulation experiment. The simulation results show that the support vector machine(SVM) can effectively identify the paraffin problem, and can accurately complete intelligent diagnosis of paraffin deposit.Fourth, when the pumping system occurs paraffin, needing the operation of paraffinremoval. This article firstly carries on the comparison to the current mainstream method of paraffin-removal and analyze the advantage of electric dewaxing technology, and then electric heating dewaxing system is mainly composed of two parts about the high frequency power supply and heating cable. Including high frequency power supply using alternating rectangular single-phase alternating AC and rectifier inverter circuit output through the transformer voltage regulation, by changing the inverter circuit of IGBT open complete frequency control for single-phase alternating current. Heating cable using carbon fiber as the main material, the experimental data result of the heating temperature demonstrate that the increasing temperature by heating can meet the paraffin-removal condition.