Optimize On Economical Working Measures Of Suck-rod Pumping System

The suck-rod pumping is one of the traditional oil extraction methods in oil industry at home and abroad, and it has been dominant in our national oil exploitation. The oil fields in our country about 80% of the wells are to use the suck-rod pumping system. And about 60% of the production fluid volume, 75% of oil production is depended on this method. The suck-rod pumping unit with its simple structure, easy manufacturing, high reliability, durability, easy maintenance to meet the on-site conditions, etc., in the oil production machinery occupies a pivotal position. However, there are also many drawbacks for the unit, such as the efficiency lower, energy consumption, big, pumping time, and poor balance performance. Especially, the main problem of the rod pumping unit is larger energy consumption and lower efficiency. For example, the average efficiency of the conventional beam-type pumping system is only 16%~23%. Therefore, the energy-saving of the rod pumping system has become the focus of widespread research. The variety of energy-saving oil pumping units, motors and electric control box are used in many oil fields, and these energy-saving products improve system efficiency of pumping wells in a certain extent. However, this will produce some problems, such as whether they can be used in combination, and whether it is a single arithmetic stack for these energy-saving products. Therefore, the study on the economical working measures of suck-rod pumping system has a very important economic and social significance.In this paper, according to the rod pumping system of the structural characteristics and energy consumption is big problem, and the principle of energy-saving, the whole suck-rod pumping system is divided into six modules: the electronic control box unit, motor unit, pumping units, wellhead unit, sucker rod unit and pump unit. The overall efficiency of the system is decomposed into the efficiency of the various sub-units, and the energy distribution of each unit is studied. The appropriate testing procedures and evaluation method of the energy-saving effect are constituted according to the test conditions and test point analysis.Secondly, on the base of the analysis for the motor power and operational efficiency, pumping V-belt transmission efficiency, optical efficiency, and packing efficiency, in order to study the energy loss of ground equipment thoroughly, the ground equipment is decomposed three parts: an electrical control box unit, motor unit, belt reduction gearbox and four-bar linkage (pumping unit). The average efficiency of the motors, the belts, the gearboxes and the effective load factor of the suck-rod pumping is analyzed roundly.Then, the energy-saving features and principle of the pumping units, motors and motor control boxes are carried out the theoretical analysis and experimental study. The system efficiency of the suck-rod pumping and the test data of integrated energy-saving rate are obtained under the conditions of the simulation test wells. And it will lay the foundation for building the multi-objective combinatorial optimization database of the suck-rod pumping system.On the basis of the above-mentioned study, a mathematical model of the economical working measures of suck-rod pumping system is established with the highest system efficiency, the lowest operating costs and the whole benefits as the goal, respectively. And the optimization model has constraints of the nonlinear mixed discrete variable optimization problems. The economic operation and management of pumping wells boundaries and standards for energy-saving management implementation, as well as measures to implement the effects of pumping wells transformation and adaptation conditions are studied. On the basis of these constraints, the mathematical models can be used to optimize the diagnosis of producing wells, therefore the feasibility of technological transformation can be determined, and the reform implementation plan can be proposed.Finally, the suck-rod pumping system energy-saving measures economic performance optimization software is developed in the C++ Builder integrated development environment. The pumping wells has been optimized and diagnosis with the software, and five wells running poorly are carried out technological transformation, the test data of the operation before and after are compared and analyzed. The results show that the optimal energy-saving effects are very remarkable.