Simulationand Optimation Of High-inclination Welllifting System

In recent years, the number of highly deviated wells increases because of limitationsground conditions and development stage. The highly deviated wells trajectory is a curvedspace curve. Sucker rod in tubing stress condition is more complicated, and partial wearproblem is more prominent. Currently the majority of oil fields using a large number ofsucker rod centralizer configuration methods, making sucker rod resistance increases evendoes not work in the down. In this paper, combined with the actual situation of oil fieldsand given the number of centralizers as a precondition to allow some positions intocontact principle, in order to optimize the configuration centralizer of oil production. Theconcept for the actual oil production is significant. The main contents are as follows:The well trajectory is simulated according inclinometer highly deviated wellbore data;the environmental load consisting of highly deviated wells are analyzed. Taking intoaccount the loss of resistance along the way and centralizers coupling and local head loss,damping coefficient calculation method is improved.Considering the impact of inter-Coulomb friction between sucker rod and tubing, thehighly deviated well sucker rod axial vibration simulation model is established and theoverall simulation algorithm is established by using numerical integration. On the basis ofthe Wave Equation, the system dynamics simulation model parameters are established.Combined with spatial beam element model and two-way spring element model, thehybrid finite element simulation model is established and contact position and the contactpressure between the simulation of sucker rod and tubing. Combined with the practicalrequirements of oil fields, centralizer arrangement pitch is optimized under the premise ofa given number of centralizers.The highly deviated wells pumping system optimization problems are specificallystudied based on the simulation results of dynamic parameters in the system. Pumpingmachine model preferred by using the fuzzy comprehensive evaluation of mathematics.Sucker rod combination is designed by using the equal strength theory. The maximumefficiency of the system is the target function, and considering of many factors, thesimulation model parameter optimization swabbing is established and get the optimal solution.