Study On Quantitative Analysis Technology For Heavy Oil Pumping Well Based On Dynamometer Card

At present, more than95%of the oil well adopt mechanical recovery mode in our country, one of the main is conventional rod pump oil production mode. Oil well production measurement is an important work in the management of oilfield production. Timely and accurate oil well production material is the important of investigating unit time production of Wells, mastering the dynamic situation of underground reservoir block, predicting and evaluating development potential of oil well block, analysising and grasping the global capacity situation of oilfield, establishing a reasonable oil field production plan. At the beginning of this century, with the deepening of oilfield development, domestic oil field ask more of oil well production measuring respectively from the ground construction and production management. The dynamometer card quantity oil technology is a new measuring technology,which need no layed pipelines、 separator, a station, with low project investment, and meet the continuous, real-time, automatic requirements, is the feasible scheme instead of the small measurement model.For a long time, annulus dynamic liquid level of pumping unit well is measured by acoustic sounder, the artificial regular operation, it is difficult to long time continuous test, and because of the dynamic liquid level test instrument is influenced by die oil ring of tubing-casing annulus and underground dog legs, test and analysis results are different from the practical liquid surface. At present other measurement methods (such as electric air gun, electric nitrogen bottles) are also used, but because of complex technological structure, higher cost, short use cycle, it is difficult to promote. In recent years, people study how to apply the dynamometer card material to calculate the dynamic liquid level depth. The dynamometer card is a description of pumping system function, liquid production has certain relation with dynamometer card of the oil Wells, the dynamometer card can predict the output of oil Wells, dynamic liquid level, calculate the maximum torque of crank, shaft friction load and well pumping unit efficiency of the system, finally analysis and diagnosis working condition of beam pumping unit, predict service life of sucker rod。First of all, this paper establish the Gibbs oil well diagnostic mathematical model, and seek the solution of the mathematical model, use the method of variable separation to solute wave equation, and give the Fourier series from of load and displacement. Then calculate indicator diagram, calculate the top dynamometer card and pump dynamometer card, it also discussed cohesion condition of the multilevel sucker rod in different diameter position, according to these conditions, draw recursion formula of coefficient at all levels of sucker rod.Secondly, this paper make quantitative analysis of indicator diagram, mainly introduced the ground dynamometer card, dynamometer card of sucker rod at all level and pump dynamometer car and their application. Calculate crank shaft torque according to the suspension loads,the types of pumping unit,used strokes weight of counterbalance and balance radius According to the rate of the maximum crank shaft torque and rated torque of reduction box, and the rate of the maximum load of polished rod and the maximum load pumping unit suspended points allowed, load utilization ratio and torque utilization can be obtained, thus to judge beam pumping unit is overloaded or not. Calculate the maximum and minimum load and the maximum and minimum stress according to dynamometer card of sucker rod at all level, obtain stress of sucker rod at all level by API modified Goodman method, in order to analysis and judge the design of sucker rod is reasonable or not. This paper explain the principle of oil measure from pump dynamometer card and the calculation method of plunger effective stroke, this paper studies the calculation model of curvature of pump dynamometer card on the basis of studying the relationship of pump dynamometer card, valve close and open point position and plunger effective stroke, and then puts forward the new calculation method of piston effective stroke, and gives the the main calculation steps of thep plunger effective stroke from pump dynamometer card. This paper also introduces how to calculate liquid production using pump dynamometer card, Mainly calculating liquid production by the effective stroke. Also calculation principle and calculation method of the depth of dynamic liquid level is deduced. By comparing the calculated value of dynamic liquid level and the observed data of the depth, the results show that the error of dynamic liquid level depth are small, it saves the cost, and can be widely expanded in the oilfield. This paper also calculates system efficiency of pumping unit well according to the pump dynamometer card, mainly discusses the ground efficiency and shaft lifting efficiency.by calculating wellbore lifting efficiency of6Wells in the GuDong oil oilfield, and the results show that the calculation of pump shaft lifting using pump dynamometer card is feasible. Because oil of GuDong is very thick, the paper discussed shaft friction load of on the problems of the heavy oil pumping Wells, the friction friction of upstroke and downstroke and total friction friction of sucker rod in state of pump.By comparing calculated value of friction load of6Wells of GuDong and the measured friction load, it can be seen that the accuracy of calculating friction load using pump dynamometer card is higher. Finally, this paper selects the results of nine pump dynamometer card from quantitative analysis calculation software in GuDong, it analysis the well working condition,and diagnosis pump problems,at the same time it discussed the fatigue limit of sucker rod by combine maximum and minimum load of suspension points with stress, study the factor of suspension load vary impacted pumping unit well-working parameters of pumping unit become larger, paraffin, the increase of water content, and finally estimate the fatigue life, determine working time of sucker rod according to the calculation results in practice to arrange inspection term of sucker rod, avoid rod parting, as a result, the fatigue life prediction provides the foundation for effective design of sucker rod string.Measurement of ground dynamometer card is simple, this article build quantitative analysis mathematical model through theory analysis, build " The Quantitative Analysis software for Heavy Oil Pumping Well based on Dynamometer Card ", this software has the function of pumping well working parameter calculation and the diagnostic analysis. It can calculate the liquid productionand the dynamic liquid level conveniently and accurately, the crank torque and efficiency. This software system is compiled in Windows2000environment used Visual Basic6.0language. Software can be operated simply, easy to use, it has large popularization and broad industrial application prospect. Stratigraphic characteristics of GuDong oilfield is complex with uneven distribution of property, crude oil viscosity, higher content of pectin asphalt. This paper do research of oil measurement using dynamometer card, dynamic liquid level analysis, viscosity reduction process parameters and working condition analysis on heavy oil pumping unit well of GuDong, this will has the very vital significance to improve overall economic benefit of oilfield development of heavy oil in GuDong.