Abstract:

The factors and mechanism of damages of injection water quality to reservoirs have been analyzed, based on the characteristics of reservoirs and fluid from Taixing oilfield. Water injectivity is mainly affected by two major factors,i.e.water-sensitive damage and precipitation and scaling caused by the incompatibility between injection and formation waters.To prevent injection water causing damages to reservoirs, it is necessary to put antiexpanding and anti-scaling additives timely, regularly and quantitatively. After numerous tests, the antiexpanding additives TDC-5 and A-25, and anti-scaling additives TH-8185 show relatively good results. Additionally, by improving water treatment technology and setting up desoxygenation and membrane-filtering systems, the contents of dissolved oxygen and suspended solids in the water might come to the standards of injection water quality.

Key words: injection water, water quality, reservoir, damages, countermeasure