Process optimization and mechanism of oil-based drilling cuttings treatment based on hydrophilic deep eutectic solvent

Conversion Mechanism of Organic Matter While Cleaning Oil‐Based Drilling Cuttings Using Surfactant‐Free Microemulsions

“…As shown in Figure 7 (a, b), SEM images show that the OBDCs before cleaning are particles of different sizes, which were agglomerated from smaller mineral particles and appeared as granular and flaky structures. After the cleaning of SFMEs, the particle size of the residual solid is more uniform than that of the OBDCs because the base petroleum of agglomerated mineral particles is effectively removed, but it is still agglomerated from granular and flaky fine minerals (Figure 7 (d, e)) [35] …”

“…After the cleaning of SFMEs, the particle size of the residual solid is more uniform than that of the OBDCs because the base petroleum of agglomerated mineral particles is effectively removed, but it is still agglomerated from granular and flaky fine minerals (Figure 7 (d, e)). [35] As shown in Figure 7 (c, f), the weight percentages of O and Si in OBDCs are relatively large (26.37 % and 13.27 %, respectively), and the weights of O and Si in the residual solid phase after the cleaning of SFMEs are 33.62 % and 19.81 %, respectively, and there is no significant change. This indicates that OBDCs and the residual solid phase are mainly composed of quartz, feldspar, mica and other minerals with SiO 2 as the main component, [36][37][38] and the composition and content of these minerals are not greatly affected by the cleaning process.…”

Treatment of oil-based drilling cuttings by floatation-advanced oxidation two-step process

“…At last, the oil content of drilling cuttings was calculated according to ref. 26 . The degreasing solution was reused and base oil was recovered for preparing oil-based mud.…”

“…In our previous study, 26 a surfactant-free degreasing solution was proposed, which consisted of hydrophilic deep eutectic solvent (DES, mixture of choline chloride, methanol, and water) and mineral oil. The DES had low surface tension and could weaken the base oil adsorption on the surface of cuttings, and mineral oil dissolved the base oil.…”

“…Concentration of PAH in the treated OBDC and limit values nd the oil content of US + O 3 was much lower than that of O 3 and US. There may be two main reasons why the US can enhance O 3 oxidation and reduce oil content:26 (1) the division effect of ultrasonic wave promoted O 3 bubbles to be crushed into microbubbles, which can greatly improve the O 3 dissolution rate in water and increased the O 3 concentration. Base oil can be rapidly oxidized and degraded by high-concentration ozone.…”