Research Of Dedicated Power Supply System For Oil Well Casing Cathodic Protection With Pulse Current

Oil well casing is an important facility for oil well. Impressed current cathodic protection technology is a standard method to prevent the corrosion of the tubing outer. And the potentiostat is the key equipment of impressed current cathodic protection system. However, the traditional DC-Potentiostat hasn’t enough protection ability for deep or ultra deep well’s casing cathodic protection. It’s proved in practice that the pulsed current cathodic protection can effectively solve the degree of protection problem. Due to without clear protection mechanism on plused current cathodic protection, this technology has not been widely used.which hinder the development of the dedicated pulsed power supply equipment for well casing cathodic protection.Based on the requirements of the plused power, this paper is present from the influence factors and rules used in the well casing cathodic protection and technical indicators firstly. Then, the overall scheme of the power supply on the power supply topology and the principle are shown. The chosen for key components and the design of the parameters are analyzed following. And the simulation is analyzed. The hardware control system for power supply consisted of the core control chip SH99F100 microcontroller, touch and display integration screen as human-computer interaction media are disgned in this paper. On the software design,the incremental PID control algorithm is used to closed-loop control of the output current and oil well casing potential. In addition, the wireless data transmission system based on the GPRS technology is relized for the remote monitoring system of the oil well casing cathodic protection. Finally, a 110 V / 30 A special power supply prototype for oil well casing cathodic protection with pulse current is successfully developed. Then, some experiments are debugged. And the power sypply’s current and the performances used in the well casing cathodic protection are anlysised. The simulation and experiments areshown that the main circuit and control system of the power supply are designed reasonably with small size, light weight, good dynamic characteristics and high intelligentize degree. The oil well casing pulse current cathodic protection system is proved excellent and achieved the desired electrical performance requirements.