Effect of Carbon Dioxide Corrosion and Temperature on Strength of Oilwell Cement

When the water environment around is relatively stable, carbon dioxide and temperature become the two major factors affecting the strength of oilwell cement. In order to understand the affecting extents, the compressive strength of corroded cement samples were examined under different corrosion conditions by carbon dioxide and temperature. The corrosion mechanism of oilwell cement by carbon dioxide and the corrosion effects on the compressive strength of oilwell cement are investigated. The results show that in the early corrosion period of 7~14 days, the compressive strength increased with increasing the curing temperature and the carbon dioxide pressure. The strength under several temperature cycles is higher than the room temperature strength.