Abstract: The increasing amount of oil-based drilling cuttings is generated during oilfield extraction process with the development of the petrochemical industry, which would result in serious harm to human living and natural environment. Thermal plasma has the characteristics of high temperature, high energy density and controllable reaction atmosphere, which has obvious advantages in treating oil-based drilling cuttings hazardous waste. This article adopts plasma technology for harmless treatment of oil-based drilling cuttings, aiming to convert them into environmentally friendly amorphous substances through thermal plasma technology, thereby achieving harmless treatment of oil-based drilling cuttings. Firstly, the water content and oil content in oil-based drilling cuttings were tested through heat treatment, and the basic physicochemical properties of oil-based drilling cuttings were analyzed. Furthermore, the oil-based drill cuttings were directly fed into the plasma arc, and the microstructure, phase composition, and particle size distribution of the oil-based drill cuttings before and after plasma treatment were characterized. Finally, the influence of silica powder on the plasma treatment of oil-based drilling cuttings was investigated. Experimental results indicated that oil-based drilling cuttings were mainly composed of BaSO4, crystalline SiO2, and CaCO3. After plasma treatment, the morphology and structure of oil-based drilling cuttings undergo significant changes. There was a clear wide distribution of bulging peaks within the diffraction angle range of 20°~35°, and the content of amorphous material in the powder reached 43.8wt%. The glass content of oil-based drilling cuttings after plasma treatment further increased by adding SiO2 powders, and the final product achieved the content of 83.3wt%. At the same time, the concentration of metal elements such as Cu, As, Cd, Ba, Fe, etc. in the product leaching solution significantly decreased. Therefore, thermal plasma technology is effective in the harmless treatment of oil-based drilling cuttings and has good application prospects.

Key words: thermal plasma, oil-based drilling cuttings, silica, glass material

摘要： 等离子体具有温度高、能量密度大、反应气氛可控等特点，在处理油基钻屑危废中具有明显优势。本工作采用等离子体技术进行油基钻屑的无害化处理，拟通过等离子体技术，将油基钻屑转化为环境友好的玻璃态物质，从而实现油基钻屑的无害化处理。首先通过热处理工艺测试油基钻屑中的含水率和含油率，并掌握油基钻屑的基本物化特性；进而将油基钻屑直接送入等离子体弧中进行处理，并对处理前后油基钻屑的显微形貌、相组成及粒度分布等特性进行表征；最后考察了外加二氧化硅粉体对等离子体处理油基钻屑效果的影响。结果表明，油基钻屑主要由BaSO4、结晶SiO2和CaCO3构成，经过等离子体处理后，油基钻屑的形貌和结构均发生显著变化，产物在2θ衍射角20°~35°的范围内存在明显的宽分布鼓包峰，粉体中的玻璃体含量达到43.8wt%；通过添加SiO2提升油基钻屑处理后的玻璃体含量，当SiO2添加量为40wt%时，产品中玻璃体含量达到最高，为83.3wt%；同时产物浸出液中的金属元素浓度，如Cu, As, Cd, Ba, Fe等均明显下降。因此，等离子体处理技术对于油基钻屑的无害化处理具有显著的效果，具有良好的应用前景。

关键词: 等离子体, 油基钻屑, 二氧化硅, 玻璃体材料