Research On Erodible Mechanism And Protected Technology Of Steel In Oil Field Hot Water System

In production of petroleum industry, thermodynamic system mainly includes heating furnace, heat exchanger, cooling condenser, oil well production lines, etc. These facilities will be eroded and scaled while they touch with water and steam with high temperature and high pressure. If high rigidity water with high hardness enters into the thermodynamic system, scale is easy to be formed so that heat conduction will be lowered and the tube will be damaged. Dissolved oxygen in water also corrodes the thermodynamic equipment. Corrosion and scale is a prevalent problem for oil field hot water system in China, which influences the life of production facilities and normal operation of crude oil production. The anticorrosion issue on the system is more and more urgent because of its importance. Through the research on the problem, it brings forward economic and effective solution, which is a tremendous contribution to operation safety and recede eroded speed and decrease crude production cost. This paper covers the research about erodible mechanism and protecting technology both for domestic and foreign oil fields, which fully understood the status of anti-corrosion pipeline with hot water. And also, it confirms corrosion types and products through research and analysis on site. Based on different stations and blocks, a general investigation on water quality is carried out from wellspring exit, overhead water storage discharge, cycling water tank discharge, heating furnace to backwater to analyze water quality and its corrosion and predict scaling trend. The water quality changing and corrosion scale shall be confirmed before chemical and physical methods being adopted to protect the water and heating system. The testing result shows that hot water system at 12 stations in Production Division No. I of Huabei Oilfield was not suffered from acid and bacteria corrosion. There are not encrusting corrosion except Gaoyilian station. The oxygen corrosion is the major factor and the corrosion is more serious with the ehahancement of concentration of oxygen, temperature and velocity of flow. The applications of deoxidant and anti-corrosion agent is good, but the corrosion resistance at high temperature is not good and the protecting film is scaled off easily and the heat equipment will be corroded under the scale. However, the application of sponge filter iron can make the content of oxygen less than 0.05mg/L and the corrosion rate lower than 0.03mm/a. It can deoxidate the oxygen in water and protect equipments well. Furthermore, it can be recycled after cleaning. Through the research on chemistry and technical anti-corrosion, the paper brings forward economic and effective resolvent to lower corrosion speed and decrease crude production cost.