| The tapping potential work has been the main task when Shenli oilfild had stepped in high water cut stage. Horizontal well technology has become one of the most important way to increase the production in Shenli oilfild while the requirement for the quality of cementation was also facing up to increasing challenge. The mainly existing cement slurry system had problem in mass discrepancy of top and bottom cement, vulnerable to formation condition, completion and stimulation treatment. Therefore, developing a novel slurry system with intelligent self-healing ability is of great significance to solve these problems.In this paper, a novel cement self-healing agent was prepared by the optimization of light calcification magnesium salt, crystallization agent and slightly soluble materials. Then self-healing agent was applied to fiber cement slurry to evaluate the self-healing abilities under the methods designed according to the standards existed and experiment conditions. Finally, the micro-structures of self-healing cement were characterized and analysed by SEM, X-ray diffraction to explain the self-healing effects.The experimental results showed that the effect of self-healing agent could be enhanced through raising temperature within certain realms, the self-healing cement was stable, the thickening time was controllable and could resistant the pollution of 5% water base drilling fluid. The difference between top and bottom of the cement were negligible and the micro-crack could healed. The secondary cementing strength of self-healing cement were 62.5%,89.2%,57.4% and 48.3% over the fiber cement after curing for 7d. The permeability of self-healing cement reduced more than 90%. The compressive strength of self-healing cement remained stable and permeability was lower about 16% after re-fracturing for 28d. The compressive strength of self-healing cement decreased evidently and permeability were reduced about 56% and 60% after cross-fracturing for 28d.
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