| abstract |
The invention discloses an oleophilic cement slurry which can improve the sealing performance of oil-bearing cementing interface. The cement slurry comprises the following components in parts by weight: 100 parts of cement, 35-65 parts of water, and 3-8 parts of water loss control. agent, 2-5 parts of retarder, 0.5-1.7 parts of anionic-nonionic surfactant, 0.5-1.7 parts of anionic or non-ionic surfactant with HLB value of 8-15, 0.02 part of defoamer, 20 ~25 parts strength stabilizer, 10-80 parts density modifier, 1 part dispersant. The cement slurry of the invention has lipophilic ability, realizes good cementation between the cement sheath and the first and second interfaces of oil-bearing cementing, and can also overcome the insufficient practice of only using pre-fluid to make the interface achieve wetting and reversal, and greatly improves the conditions of oil-based drilling fluid. The sealing effect of the lower cement sheath reduces the dependence on the performance of the pre-fluid. |