Establish Comprehensive Techniques For Controlling Friction Between Rod And Tubing On Rod Pumped Wells In HB Test Area

Many studies have made by domestic and international researchers on the problem of rod and tube partial-wear, and also developed techniques for controlling friction which based on each principles and aimed at different friction factors, and acquired actual application effect in many oilfields. At the same time, these techniques also have some defects, and can’t generally applicable to all kinds of friction between rod and tubing in every oilfields, so in consideration of friction feature in different block of different oilfields, it would be particularly important to establish comprehensive techniques for controlling friction between rod and tubing and use new method to fill the defects of existing techniques.Friction between rod and tubing has become the principal influence factors in HB test area’s daily production, the main reason is that reservoir buried depth is large, average daily produced fluid volume is low, viscosity of well fluid is high, pump efficiency is unstable in daily production, paraffin precipitation and corrosion phenomenon is serious in partial test area, stress state of rod and tubing down hole is complex, and some existing techniques for controlling friction can’t completely adapt to the situation of friction in test area, or it can’t completely satisfied the conditions of controlling friction in test area. All these factors led to the serious phenomenon of friction between rod and tubing in this test area, and shorten the rod and tubing’s service life in this area, increasing the cost of production, so it is urgent to optimize the comprehensive techniques for controlling friction to solve all the existing problems.Based on the existing research results, this paper makes a statistical analysis for the status of production and operation feature of producing well, operating well and friction well in 2012 to 2014 on different work zones, come to the law and mechanism between every main influence factors and friction ratio of rod and tubing on rod pumped wells in this test area; uniting for test area, sort for each factors’ influence extent to friction between rod and tubing, then confirm the primary and secondary relations and targeted optimize the comprehensive techniques for controlling friction in different operation areas; on the basis of the existing calculate of each axial force, the sort of influence factors in different test areas as premise, analyze the force situation of rod and tubing down hole in detail, and draw the 3D well trajectory diagram, corresponds to the axial force on each part of rod and tubing, visually display force situation of each part of rod and tubing and the distribution of friction position, to establish precise prediction model for friction position; combine with the prediction model for friction position and influence factors of friction in each test areas, build the model of comprehensive techniques for controlling friction, and optimize the existing techniques models for controlling friction,such as: single well production parameter, sucker rod combination, the number of centralizer, the setting position and weighing rod’s setting length; last, combining with above models, we establish a optimization software about the comprehensive techniques for controlling friction in HB test area.The software has been used in HB test area from the second half of 2014 to now. Techniques for controlling friction were carried out among 142 old wells, and techniques were formulated among 38 new wells. The average pump inspection cycle is extended for about 150 days, which means the good effect and certain practical value.