2017毕业论文-机抽井井下示功图诊断及应用

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1、摘要当今世界石油工业中，有杆泵抽油方式是机械采油的主导方式，其无论在井数上还是在产油量上均占机械采油的主要部分。有杆抽油是一个系统性很强的机械采油方式，它由地层、井筒、地面设备三个子系统构成。要保持有杆抽油系统高效地运作，必须使三个子系统相互协调工作，而机抽井井下示功图的诊断技术则是保障深井泵高效工作的主要技术。它可以及时地对深井泵故障进行诊断，分析故障原因，采取有效措施，提高系统效率。本文着重介绍深井泵诊断数学模型的求解过程及其应用。深井泵的诊断数学模型结合了描述杆柱动力学特征的波动方程和抽油机悬点运动规律

2、，上边界考虑了常规型抽油机的运动规律，下边界考虑了深井泵的受载情况，在求解波动方程时，采用有限差分法求解，利用经验公式求解阻尼系数，通过求解波动方程、确定泵处的载荷和位移，绘制井下示功图，对泵的工况进行诊断。基于上述理论，特别是在深入研究示功图形态、故障特征以及生产设备条件的基础上，将井下示功图大致分为窄条或不出液类、完全上冲程特征故障类、完全下冲程特征故障类以及上下冲程特征故障类，使其更易于故障诊断。关键词：机抽井；示功图；波动方程；有限差分；故障诊断AbstractIntheoilindustryofth

3、eworld,therodpumpingisaleadingmodeinmechanicalrecovery,bothinitsnumberofwellsandinproductionitoccupiesthemajorpartofmechanicaloilproduction.Sucker-rodpumpingisakindofartificialliftswhichhasaverystrongsystematicness.Therodpumpingsystemiscomposedbythreeparts,

4、layer,wellboreandsurfaceequipment,whichmustworkinphasetomaketherodpumpingsystemrunningwithhighefficienceandenergysaving.Butthediagnostictechnologyofdownholedynagraphshowesaprincipalmeansfordeep-wellpumptoworksafelyandeffectively.Itcandiagnosisthefailureofde

5、ep-wellpumptimely,analysisreasonoffailure,takeeffectivemeasuresandimprovesystemefficiency.Thisarticlefocusesontheprocessofsolvingmathematicalmodelofdeep-wellpumpandapplianceofit.Themathematicalmodelofdeep-wellpumpuniteswaveequationwhichdescribesdynamicfeatu

6、resofstringandthelawsofsuspensioncentremoving.Theupboundaryconditionconsidersthelawsofconventional-typepumpmoving,thedownboundaryconditionconsidersconditionsofdeep-wellpumpbearingforce.Usingfinitedifferencetosolvewaveequationandadoptingempiricalequationtoso

7、lvedampingfactor.Throughsolvingthewaveequation,solvingloadinganddisplacementofpumpanddrawingdownholedynagraph,Itcandiagnosisconditionofpump.Basedontheabovetheory,Particularlyonthebasisofresearchingdownholedynagraph,featureoffaultandconditionsofproductionequ

8、ipmentdepthly,downholedynagraphcanbeclassifiedintoseveralkinds,thereasonasitcandiagnosisconditionofpumpconveniently.KeyWords:PumpingWell;DynagraphCard;WaveEquation;FiniteDifference;FaultDiagnosising大庆石