ASSESSMENT OF ENVIRONMENTAL SAFETY OF SOLID PHASE OF DRILLING SLUDGE AFTER CENTRIFUSION SEPARATION

Abstract

The purpose of the article is to determine the degree of environmental safety of the solid phase obtained after separating drilling sludge in a centrifuge for use as a commercial product, in particular, a filler for building materials. Samples of drilling sludge taken from wells No. 77 of the Semirenkovske field (No. 1, 2, 5, 6), Machukhi No. 54 (No. 7–10). The degree of ecological safety of the solid phase of the drilling sludge was assessed by the indicators of radioactivity (dosimeter device), mineralogical and chemical analysis. The phase composition of the samples under study was determined by the method of X-ray diffraction, the chemical composition, in particular the content of heavy metals, by the methods of X-ray fluorescence analysis and atomic absorption spectrometry. The level of radioactivity of the investigated samples of drill cuttings and its individual phases at different stages of separation in the VSD-950 centrifuge does not exceed the normative permissible threshold value (< 0.3 μZv/h). The hypothesis of an increase in the concentration of elements characteristic of rocks, and, conversely, a decrease in the concentration of chemical elements that make up the drilling fluid and go to the liquid phase after separation in a centrifuge, has been experimentally confirmed. Heavy metals (iron, nickel, copper, lead, chromium, zinc) form a separate group of chemical elements identified in all samples. However, their content is very insignificant – no more than 0.3 %, and for some metals – at the level of traces.