Offshore platform oil extraction electric submersible pump variable frequency driving system

Abstract

The invention provides an offshore platform oil extraction electric submersible pump variable frequency driving system. The system is characterized by comprising two or more offshore platform generators, one or more frequency converter phase shift rectification units, two common direct current buses arranged in parallel in a spaced mode, multiple inverters and electric submersible pump motors with the number equal to that of the inverters; each offshore platform generator is connected with the input end of the corresponding frequency converter phase shift rectification unit through an alternating current bus, the output end of each frequency converter phase shift rectification unit is connected with the two common direct current buses in parallel, the two common direct current buses are connected with the input end of each inverter in parallel, and the output end of each inverter is connected with the corresponding electric submersible pump motor. The offshore platform oil extraction electric submersible pump variable frequency driving system can be widely applied to the offshore platform oil extraction process.

Description

technical field [0001] The invention relates to a variable frequency driving system of an electric submersible pump, in particular to a variable frequency driving system of an electric submersible pump for offshore oil production. Background technique [0002] The electric energy generated by the platform generator on the offshore oil platform is firstly reduced to 400V by the step-down transformer, and then input into the frequency converter. After the voltage is required, the electric energy is transmitted to the electric submersible pump motor through the submersible cable, and the electric submersible pump motor converts the electric energy into mechanical energy, driving the submersible centrifugal pump to rotate at a high speed, the liquid in the well is sucked into the pump, and gradually pressurized by the pump impeller. The tubing flows to the ground. In the electric submersible pump oil production system, through the application of the frequency converter, on the ...

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Problems solved by technology

[0003] like figure 1 As shown, in the current variable frequency drive system for oil production electric submersible pumps on offshore platforms, the electric energy generated by the generator 11 on the offshore platform first passes through the step-down transformer 12, then passes through the incoming filter 13, rectifier 14, and inverter 15, and then is boosted. After the transformer 16 drives the corresponding electric submersible pump motor 17 to work, but the above-mentioned system has the following problems: 1) Due to the large number of wellheads on the offshore platform, the electric energy required by the electric submersible pump motor 17 corresponding to each wellhead first needs to go through a step-down After the transformer 12 is stepped down, it is boosted by a separate step-up transformer 16, and multiple transformers occupy a large space on the platform

In addition, the electric energy undergoes multi-stage conversion, so the efficiency of energy utilization is low; 2) The electric submersible pump motor 17 corresponding to each wellhead is equipped with a passive filter and frequency converter separately, which takes up a lot of space, and the configuration is unnecessary. The harmonic filtering effect of the source filter is poor, and the harmonics at the input side of the electric submersible pump inverter have an impact on the power quality of the platform; 3) Due to the particularity of the offshore oil industry, the selected inverter has a large margin. The phenomenon of "big horses and small carts" often occurs during the actual operation of the inverter, resulting in reactive power overcompensation generally caused by the configured passive filter to the low-voltage system on the input side of the inverter.

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