Pure cement generally be used on most traditional drilling, but in exceptional circumstances regulate cement density is the key to successful completion and long- term isolation.
There are several methods of adjusting the slurry density has been used. These methods can be used alone or integrated use.
For example: by adding water dilution, plus hollow ceramic microspheres method, add the foam method. Dilution water and add the cement foam-regulating unstable performance. Plus hollow ceramic microspheres law, and hollow ceramic beads themselves strong enough, in the slurry injection wells can break, resulting slurry density rises.And in the deep mining of oil, adding high-performance hollow beads of grout has a certain fluidity in the process of injection wells, grout injection wells, it can quickly condense, and reached a considerable strength in the short term, the hardened cement pasteIt has 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 increase 1.0-2.0mpa. Depth of 7000 meters above the bottom hole temperature up to 200 degrees Celsius, and pressures up to 125mpa.Thus high temperature and pressure, to influence various properties of cement, oil well cement production and use of the most important issues. The strength of the cement slurry high temperature decreased significantly. Added with cenospheres slurry, not only to reduce the density and can withstand prolonged high pressure and high temperature strength, this lightweight cement outperforms other conventional light cement.
This article comes from Baidu library