Drilling is now the most widely used material is cement, generally pure cement traditionally applied to drilling would be sufficient, but with the emphasis on safety, began to consider many external factors, but in exceptional circumstances to adjust the density of cement is the key to successful completion of the long-term isolation.
The market, there have been several slurry density adjustment method is used. These methods can be used alone or integrated use. Example: By adding water dilution, plus hollow ceramic beads method, add the foam method. Dilution water and add cement foam law regulating the unstable performance. The law increases the hollow ceramic beads, hollow ceramic beads and their strength is not enough, when the grout injection wells will be broken, resulting slurry density increases. It is precisely because there are flaws and shortcomings, will come up with more consistent material perseverance of its development.
When deep drilling for oil, adding high-performance hollow beads of grout has some mobility in the process of injection wells, grout injection wells, you can quickly condense, and reached a considerable strength in the short term after the grout has hardened good stability and impermeability, corrosion resistance and so on. Temperature and pressure at the bottom of the well with the depth of enhancements and improved every depth 100m, an increase of about 3 degrees Celsius temperature, pressure increases 1.0-2.0mpa. Depth of 7000 meters above the bottom hole temperature up to 200 degrees Celsius, and pressures up to 125mpa. Therefore high temperature and pressure, the impact on the various properties of cement, oil well cement production and use is the most important issue. Temperature effect of the strength grout dropped significantly. Added cenospheres using grout, not only to reduce the density and strength to withstand high pressure and high temperature for a long time, this lightweight cement outperforms other conventional light cement.