Abstract : This paper introduces the various drawbacks of traditional power supply methods for submersible electric pumps, elaborates on the advantages of variable frequency power supply, and then introduces the technical performance and characteristics of the 2300V submersible electric pump frequency converter, as well as its broad prospects for application in oilfield submersible electric pumps.
Keywords : Submersible electric pump, frequency converter, inverter output
1. Overview
With the development of my country's petroleum industry and the needs of oilfield development, it is an inevitable trend to upgrade existing oilfield production equipment with modern high technology in order to improve oil production speed and ultimate recovery rate. Submersible electric pumps (SAPs), as a new type of rodless mechanical oil production equipment, have been widely used in my country over the past decade and have been continuously improved and developed.
Working principle of submersible electric pump: It is a multi-stage centrifugal pump that works downhole. It is lowered into the well along with the tubing. The surface power supply transmits electrical energy to the downhole submersible motor through the transformer, control panel and submersible cable. The motor drives the multi-stage centrifugal pump to rotate, converting electrical energy into mechanical energy and lifting the well fluid in the oil well to the surface.
Utilizing modern automatic control technology and variable frequency speed regulation technology to provide an ideal power source for oilfield submersible electric pumps (hereinafter referred to as pumps) is an important component of this technological transformation process. Submersible electric pumps typically operate at voltage levels of 1140V and 2300V. These pumps are installed at depths of approximately 1000-3000 meters in oil wells, operating in extremely harsh environments (high temperatures, strong corrosion, high salinity, etc.). Traditional power supply methods—full voltage, mains frequency—lead to frequent failures and significantly increased operating costs. The cost of bringing a damaged submersible electric pump to the surface for repair alone reaches 30,000 yuan. The cable, worth over 100,000 yuan, needs replacement after an average of five jacking and lowering operations. The submersible electric pump requires maintenance on average every 10 months, with maintenance costs around 80,000 yuan.
Applying a dedicated frequency converter for submersible electric pumps offers the following benefits:
(1) It can realize soft start and soft stop of electric pump, extend the service life of electric pump, protect motor and cable, and save maintenance costs. (2) It improves the power factor of electric pump system and has a significant energy-saving effect. (3) It improves the quality of pipeline network, realizes closed-loop control of electric pump system, and increases the working safety of electric pump system. (4) It has high reliability and is easy to operate. It can realize continuous adjustment of output voltage and current to achieve the purpose of continuous adjustable output power, so that the electric pump oil production system is in the best working condition. (5) It improves production efficiency, facilitates overall management and scheduling, and realizes distributed control of electric pump system. (6) Oil production technology involves multiple disciplines. The frequency converter for submersible electric pump has changed from the original high-low-high mode to direct high-high frequency conversion, which is smaller in size and easier to operate.
For details, please click: A Preliminary Study on the Research of Inverter for Submersible Electric Pumps
