Effects of pipeline corrosion on the injection water quality of low permeability in oilfield

It has aroused great concern that oil and total suspended solid (TSS) contents in the Water Injection Well (WIW) exceed the standard for injection water quality in Liaohe oilfield in recent years. The quality of water from Water Treatment Station (WTS) and WIW was analyzed. Corrosivity of injection water from WTS and simulation of re-injection process were considered. The TSS from WTS and WIW was characterized using the energy-dispersive X-ray spectroscopy (EDS), scanning electron microscope (SEM) and X-ray diffraction analysis (XRD). It revealed that the major composition of TSS in both of them was organic substance, but there were some inorganic crystals (Lithium Iron Oxide, Fe3O4, Fe(OH)3 and Iron Silicon Oxide) in WIW. The simulation model for oil, TSS and ferrous ion contents was established to explain quantitatively the relevance between the corrosion of pipeline and the deterioration of injection water quality. However, it is concluded that pipeline corrosion is the dominating reason for deterioration of injection water quality.