Design principle of floating bead cement slurry
Oilfield floating beads are very important in our life, and we are also very curious about them. What we brought to you today is the design principles of oilfield floating beads cement slurry.
(1) According to the characteristics of structural reservoir in the block, the technical difficulties (such as leakage prevention, water loss reduction, high temperature resistance, etc.) and the conditions of well depth, ground temperature gradient, fracture pressure gradient and pressure coefficient, the performance parameters of cement slurry density, thickening time, water loss and cement stone pressure resistance are determined, so as to formulate the design of floating bead low density cement slurry The orthogonal design method is used to achieve the optimal combination of cement varieties, floating beads and additives, and the cement slurry mix proportion suitable for the region is selected.
(2) The selection of general parameters: ① the content of floating beads involves the relationship between slurry density and cement strength, and 20% ~ 45% is generally preferred; ② due to the low short-term water absorption of floating beads, even if the water cement ratio is slightly lower, the cement paste still has a certain fluidity, generally 0.65 ~ 0.70 water is preferred; ③ because the water content of floating beads is not easy to seep into the cement paste in a short time under normal pressure, so cement is prepared Generally, the density of cement paste is 1.25 ~ 1.45 g / cm3.