Study of patterns of changes in salt compositiondrill cuttings in the process of their disposal
E.V. Gaevaya, L.V. Rudakova
Section: Remediation and rehabilitation
Drill cuttings in their natural state have viscous-plastic properties; in a dry state they are cohesive and hard. This is due to the content of sodium ions in the absorbing complex. Features of the physical and mechanical properties of drill cuttings indicate its ability to absorb and retain dissolved salts. When gypsum is added to drill cuttings in different percentages of the waste volume, the concentration of chloride ion changes in all samples, and chloride-sulfate salinization is observed. The content of sulfate ion increases with a minimum volume fraction of gypsum application. The addition of gypsum in a
volume fraction of 15 and 20% affects the reduction of phosphate and carbonate ions. A change in electrical conductivity indicates an increase in the concentration of water-soluble salts in the water extract, which is confirmed by a direct high correlation. When adding gypsum from 7–20% volume fractions, a significant reduction in the dense residue occurs. The use of gypsum increases the filtration capacity of drill cuttings. The use of gypsum makes it possible to lighten the granulometric composition of drill cuttings due to the active coagulation of colloids. As a result of the removal of water-soluble
salts, optimal water-physical properties of drill cuttings are created, structuring and filtration properties of drill cuttings are increased. A mathematical model for predicting the dissolution of salts in drill cuttings allows taking into account uncontrollable factors (density, particle size distribution, filtration coefficient, content of water-soluble salts).
Keywords: drill cuttings, salt composition, dissolution rate coefficient
Article published in number 2 for 2024 DOI: 10.25750/1995-4301-2024-2-125-134
ISSN 1995-4301
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