Influence of flocculant reagents on the parameters of clay suspensions

The purpose of the work is to evaluate the effect of flocculant reagents on the rheological and structural-mechanical properties of clay suspensions, and to select their optimal concentration in the drilling mud. Currently, the industry produces a huge number of drilling mud flocculants that differ in their properties and composition. Most flocculants are water-soluble polymers with a large molecular weight, both of natural and artificial origin. The main purpose of such reagents is to separate the solid and liquid phases of the drilling mud during its dewatering and disposal. However, in clay suspensions, the same reagents are used as thickeners. As drilling fluids are complex systems that differ in their component composition, it is not possible to recommend a universal flocculant. During the study, the analysis of the flocculating and thickening capacity of the reagents was performed in two stages. The study defined an optimal concentration of the polymer at which maximum values of the dynamic shear stress were reached. The clay suspensions containing polymer reagents were been experimentally compared. The values of the rheological, structural-mechanical and filtration parameters of the solution were used as the evaluation criteria. The study has established the following. The reagents BEN-EX, BENTOPLUS and DRB-9 can be used to increase the viscosity of the clay solution, provided that the concentration of the additives BENTOPLUS and DRB-9 does not exceed 0.2 kg/m³. The SPECFLOC A 7950-20 reagent can be used to increase the viscosity of the clay solution in concentrations up to 0.1 kg/m³, while in concentrations of 0.2 and 0.3 kg/m³, the additive mainly effects the drilling mud as a flocculant, reducing the static shear stress of the solution and increasing the filtrate output. If the dynamic sheer stress is the only diagnostic variable when drilling with the SPECFLOC № 6919 additive, the latter can be recommended for use. In all other cases, additional research is required. The conducted laboratory studies allow us to obtain drilling fluids with a set of technological parameters that ensure high quality of the prepared drilling fluids.

drilling mud, flocculant, clay suspension, rheological properties

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