Composite Design For Sucker Rod Pumping System

For the sucker rod pumping system, especially for the vertical well, proven theory and software system have already been applied both at home and abroad.But for the directional well, because the rod string and pipe string's force situation is different from the vertical well, and the application of the centralizers, make the sucker rod pumping system's force analyses become complicated.Because the sucker rod's dynamics behavior analyses in directional well is very great different from the vertical well, the optimization theory of the vertical well can't be used in the directional well.The in-depth theoretical analysis and substantive simulation have been done on the sucker rod pumping system for the directional well, and research work mainly includ the following:(1)Used two kinds of methods:interpolation algorithm and polynomial fitting method to simulate the directional well's track, and the simulation software is MATLAB.And analysed and compared these two kinds of algorithm's characteristics.(2)Analyzed the directional well sucker rod's dynamics behavior (especially the hollow sucker rod's dynamics behavior) deeply.For the electric heating hollow sucker rod,the temperature produced by electric heating can exert an influence to mechanics behavior ,so the hollow sucker rod's dynamics behavior is much more complicated than conventional sucker rod's dynamics behavior. The impact produced by thetemperature on sucker rod's dynamics behavior has been analyzed especially.Based on the sucker rod's dynamics behavior's analyse, both the conventional sucker rod's three-dimensional mathematical model and the hollow sucker rod's three-dimensional mathematical model are built and be solved by finite element method.(3)Based on the dynamics behavior's analysis and the mathematical model'solve, the directional well sucker rod's series are designed, and the composite design includes the ordinary rod's composite design, the hollow rod's composite design and the ordinary rod-hollow rod's composite design.(4)Through in–depth deformation analyses of sucker rod in three-dimensional well bore, and through confirm variable of designing ,set objectives function ,confirm restrain terms ,etc. steps ,established the optimum design mathematical model for rational distribution design of sucker rod centralizer, and also solved the mathematical model by MATLAB to realize its optimization design.(5)The wellbore heat transfer process has been analyzed deeply, and based on transfer of heat; the mathematical model for the wellbore fluid's temperature distribution which is heated by electric heating has been established.And the mathematical model is solved to realize its temperature prediction. And after several actual wellbores fluid's temperature's prediction, the relevant parameters have been revised, to enable the result is more accurate.(6)Developed the corresponding application software and the software considers both the directional well's situation and the vertical well's situation .We can design the rod string and the centralizer spacing by this software.We can also predict the wellbore fluid's temperature distribution which is heated by electric heating by this software.