| Oil pumping unit still dominate the oil industry by artificial lift oil production method, tube and rod string eccentric wear of pumping well is still the problems universally existing in the oil field development at present. When the oil field entered middle and later exploitation stage, because the stimulation such as water injection is adopted, the eccentric wear well number increases year by year. The national each big oilfield as well as overseas oil and gas development company are found in pumping unit wells one of the major problems is tubing and sucker rod in the eccentric wear of the up and down stroke. In oil field production, as pump setting depth increase and output liquid water cut rise, eccentric wear problem shows ascendant trend.Hailaer oilfield belongs to low productivity, low permeability oilfield, the well spend an average of3.1t/d daily fluid, reservoir buried depth is large; the average pump depth is greater than1700m. Because of heavy oil well pump setting depth, low single well produced fluid volume, low submergence depth, of the downhole rod string working conditions is complex, lead to tube eccentric wear problem is more serious. Rod tube eccentric wear has become the leading cause of hailaer oil field oil well operations, increase the rate of oil well pump inspection, and shorten the well pump inspection cycle, technology is urgently needed to solve the rod tube eccentric wear problem.Based on similar research topics at home and abroad for reference, through systemic research in hailaer oil field pumping unit Wells eccentric wear status quo, summed up the law of hailaer oilfield rod tube eccentric wear and the reasons, prevention and control of eccentric wear of research at home and abroad advanced technology, formed suitable for the eccentric wear of hailaer oilfield prevention measures. In terms of eccentric wear mechanics theory, in3d space, on the basis of borehole trajectory, the sucker rod by static load and dynamic load, the friction load and other load inductive to sucker rod column end under concentrated load and two aspects of sucker rod axial distributed load, the three-dimensional mechanical model was established by applying the micro element analysis, and the iteration method is used for solving; In terms of eccentric wear prediction, using the theory of buckling instability, survey the vertical shaft and curved eccentric wear of the critical load calculation model, and using the direct method and energy method of establishing tube wear quantity forecasting model and the solution; For vertical Wells and curved Wells, respectively, centralizer placement model is builted with the theory of compressive bar and advanced foreign technology, and solved using the dichotomy; On the basis of the eccentric wear theory and the model, using the computer language c#, SQL Server2008database, compiled for the eccentric wear prediction and prevention and control of pumping unit well system, and use of hailaer oilfield field data to test the software, the software was tested and verified the validity and reliability;At the same time, the influence of well deflection, swabbing parameters, the diameter of rod string, water cut and submergence depth and oil well pump parameters on the rod string stress were studied, applying instance, calculating, summing up the rule of main factors affecting the eccentric wear, and integrating the various technical means, with different well conditions of hailar eccentric wear supporting research on the prevention and control technology, which retarded the progress of hailaer oilfield rod tube eccentric wear. |
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