Optimization of additives for cement used in petroleum and natural gas wells

In this work, the ways of preventing casing corrosion of the wells where oil is produced, which is the main energy source of the world, were researched. Depth, temperature and cement compositions of wells previously lost due to corrosion were evaluated before the tests. Corrosion inhibitors' setting performances are compared in real field circumstances to prevent abandonment of oil wells cause of surface-chloride corrosion. 3 basic corrosion inhibitors (calcium nitrite, calcium nitrate and ethanolamine based), which are construction industry's mostly used, most suitable for oil industry's demand and performances' proven by a lot of different works, are chosen. Cementing setting time tests are held with these inhibitors in TPAO AR-GE center laboratories. In these tests, API (American Petroleum Institute) G class cement used and real field conditions stimulated as 120 °F temperature and 3000 PSI pressure to analyze setting time and setting behaviors. End of the work, %4 concentration of ethanolamine decreased the setting time up to 12 minutes and most different protection method provider, calcium nitrite, caused little increments on setting time and it was understood that this additive can be used in oil well cementing on trust. The most known cement setting accelerator in the oil field is CaCl2 are not preferred cause of chloride consisting in construction industry. In that basis, calcium nitrite and calcium nitrate's setting time researched in G class neat cement. Although, CaCl2's accelerating effect, calcium nitrite and calcium nitrate acted as a small amount of retarder. That is why, in short cement setting time demanded operations, calcium nitrite and calcium nitrate may not give positive outcomes.