Research on the impact of inorganic components on the performance of a novel self-solidified spacer fluid

• The novel spacer fluid has strong compatibility with wellbore fluids.
• The effects of inorganic components on the performance of spacer fluid are discussed.
• The reasons that hydration products and microstructure changed are analyzed.

To solve the problems that occur during cementing operations in the case of an incapable solidified layer, such as drilling fluid and spacer fluid, this paper investigated a novel self-solidified spacer fluid. The incapable solidified layer composes the interface of the well wall-cement ring-the casing wall had an empty ring and a gap, which seriously affected the cementing quality. Unlike the addition of various conventional chemical conditioning agents in the spacer fluid system, to optimally adjust the properties, this paper studied its impact on the system compatibility, rheological properties, sedimentation stability, a compressive strength by changing the percentage of the component substances, such as the inorganic suspension stabilizer, as well as CaO, MgO, Al2O3 and SiO2, and analyzed test samples using X-Ray Diffractometer (XRD) and Scanning Electron Microscope (SEM) tests. The results showed that the novel self-solidified spacer fluid has strong compatibility with wellbore fluids. In addition, bentonite, the inorganic component of the suspension stabilizer, was found to adjust the rheological properties and sedimentation stability. CaO and MgO, the inorganic components of solidifiers, were found to increase the compressive strength of the samples. This study indicates that the self-solidified spacer fluid could adjust the percentage of inorganic components to meet the construction requirements in the actual cementing operations and provide a basis for the selection of other chemical conditioning agents.