The Research And Implementation Of3D Mechanical Properties Of Sucker-rod String Of Directional Well

This paper is based on the project of Shaanxi Yanchang Oilfield Co. LTD, which is called"Mechanical Oil Production Technology Research of Low Productivity and Low EiffciencyWell of Yanchang Oilifeld". According to the problem of rod and tube eccentric wear in oilfieldproduction, taking sucker-rod stirng of directional well as study object to research3Dmechanical model of sucker-rod stirng, running optimization for distirbution of centralizersbased on application sotfware and taking the optimization into practice for two directional well.The primary coverage of this paper includes:(1)Based on the finite element method,3D mechanical model of sucker-rod stirng isestablished. With making the gap between sucker rod and tube to be dynamic constraints, thedeformation and load in axial and the high side direction of each node of sucker-rod stirngcould be solved by using the node iterative method, the stress and displacement of each node inthe next moment is solved by the Newmark method.(2)According to the boundary tracking method，the curves of load, displacement, velocityand acceleration of suspension point are automatically extracted on indicator diagram.(3)By using interpolation method, interpolation of the well trajectory data is completed forone meter intervals. And integral method is uesd to calculate the three-dimensional coordinatesof well trajectory, and to draw actual well trajectory.(4)By using the MATLAB language, the development of《Directional Well CentralizersDistirbution Optimization Software》is realized. The sotfware can calculate axial deformation,axial load and the deformation on the high side direction of each node of sucker-rod string bycombining the parameters in actual production of directional well, and optimize centralizerplacement on the rod stirng.(5)By using the《Directional Well Centralizers Distirbution Optimization Sotfware》and《Eiffciency Analysis and Optimization Sotfware of Rod Pumping System for Directional Wellof Low Permeability Oilfield》，many of test wells of the southern district of production plant ofYanchang oilfield are program output respectively, and the two of it are operated according totheir different operation schemes. Then an effect evaluation is made by comparative analysis ofplans before and atfer the construction.