IMPROVEMENT OF A DESIGN OF A BOREHOLE PLUNGER PUMP FOR PRODUCING A LIQUID WITH SUSPENDED PARTICLES INCREASED CONCENTRATION

Abstract

When a large amount of solid impurities (sand) is contained in the produced formation fluid, the operation of production wells is complicated. Their presence leads to an increase in hydroabrasive wear of parts and components of a downhole sucker rod pump and causes its plunger pair to be wedged. In addition, this leads to cork formation, which requires cleaning and flushing. To prevent this phenomenon, various types of sand filters and structural changes of plunger pairs of the rod pump are used. The analysis of the operation of sucker rod pumps for oil production at the Tuymazaneft NGDU fields of Bashneft-Dobycha LLC revealed the following main reasons for the failure of the underground part of well sucker rod pump units: blockage of suction and discharge valves (52.2 %), jamming of the plunger in the pump cylinder (36.5 %), gaps in valves (4.8 %), disconnection of the plunger from the rod (1.8 %), breakage of the rod string (1.7%), lack of tightness in the support of the plugin pump (1.1 %). As a result, the average operating time of the pump is reduced to failure and the presence of sand in the formation fluid can be considered the main problem. Based on the analysis of field data on the operation of the plunger pump under complicated conditions (increased concentration of suspended particles in the produced fluid), it is proposed to change its design. Improvement affected the pump plunger and its filter. The proposed developments have a detailed description of their design and principle of operation. Detailed field tests of the developed devices are presented, showing the effectiveness of its use. As a result of the use of pumps with shortened plungers (and the previous modes of operation of the wells did not change), good results were achieved in reducing the load in the TPS and increasing the pump coefficient, and the durability of the elements of the plunger pairs of sucker rod pumps. After examining the plungers, slight wear of the eccentric rings to center the plunger was detected. For the purpose of further use of shortened plungers, only the replacement of all rings is necessary. There is no need for expensive repair of plungers. In addition, there was no seizure of the plunger in the cylinder. Sand filters were installed in 2018 at the well Nos. 1246, 1356, 1623 NGDU Krasnokholmskneft LLC Bashneft-Dobycha. Before the filter was lowered into the wells, samples were taken that established the presence of mechanical impurities in the product. The concentration of suspended particles exceeded the norm by several dozen times, which can lead to premature failure of the pump. In addition, sludge traps were located between the filter and the shank to increase efficiency. The use of new developments together allows to increase the efficiency of the use of a sucker rod pump in difficult operating conditions.