5.7 Washing Liquid

In the process of cementing, in order to improve the slurry displacement efficiency, ensure cementing quality, before the cementing, a certain amount of washing liquid should be injected to the casing pipe. Due to the use of washing liquid, the mud cake in the walls can be scattered and washed out, so as to improve the displacement efficiency, improve casing interface, and enhance the cementing slurry interface force. Because of the drilling technology advances, the type of drilling fluid also becomes more and richer. Common drilling fluid can be divided into water base drilling fluid and oil-base drilling fluid. Water-based drilling fluid is water is prepared by water, and oil-base drilling fluid is prepared by kerosene and other oil. In order to compatible with drilling fluid, washing liquid also be divided into water-based washing liquid and oil-base liquid.

The kelioil CW series washing liquid have good osmosis, it can quickly osmoses into the mud cake in the wall and scatter and wash it out. These series products have strong ability in washing oil, soluble good in the water, good thermal stability, and good active role at low temperature. And they also have good compatibility with drilling mud and cement slurry, don’t have adverse impact on drilling fluid and cement slurry. The CW110L mainly is used to prepare water-based washing liquid, but if used to the oil-based slurry, it also has good efficiency. The CW210L is mainly used to prepare oil-based washing liquid and it also has good efficiency to the water-based cement slurry. They both can be used only and have better effect if used together. Table 7-1 is the properties of CW series washing liquid.            

Table 7-1 washing liquid’s cleaning efficiency