Cement fluid loss can cause loss of cement quality and its functionality. A common cement system with fluid loss problems is a system containing weighting agents. Barite, which is used in cement to increase the slurry weight, is one example. In this paper, the effect of barite nanoparticles (NPs) in different concentrations on cement fluid loss was investigated.

Barite NPs were generated via dry grinding method using a high-energy ball grinder. The barite NPs were added to the cement slurry in various concentrations, and a low pressure low temperature (LPLT) static fluid loss tester was used to measure the cement fluid loss in the laboratory.

It was observed that, as the nanoparticles concentration increases from 0 to 5 percent by weight of total slurry, the average fluid loss decreases by about half. Results showed that about 50 percent filtration reduction can be achieved by replacing 3% weight of normal barite with barite NPs in the cement slurry. The experimental tests presented herein also show the effect the fluid loss has on cement thickening time, clearly identifying that the cementing fluid loss must be integrated into the design of the cementing operation design and pumping schedule. It verified that adding barite NPs to cement slurry is promising from both a technical and cost saving perspective. The novelty of this research is in the application of barite NPs at low concentrations to reduce cement fluid loss significantly. Reducing the cement fluid loss can prevent many problems such as low quality cement due to poor crystallization, high equivalent circulation density (ECD), which results in formation failure during cementing jobs. The results presented herein also show a significant fluid loss effect on the cement thickening time. Lower cement thickening time seen due to fluid losses to the formation can cause the cement to set before completing cement placement, fluid channeling between the cement and formation, and low compressive strength cement.

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