AN OVERVIEW OF OIL BASED DRILL CUTTINGS WASTE ENVIRONMENTAL EFFECT AND DISPOSAL TREATMENTS

Abstract

The drilling fluid is essential for drilling operations in the oil and gas industry. It is a complex mixture of organic and inorganic materials blended together to achieve desired multi-functions. There are several types of drilling fluid commonly in use, oil-based drilling fluid considered the most hazardous and harmful for the surrounding environment because of contaminated waste produced, normally consisting of diesel, oil, asphalt, polymers, crude oil and surfactants. Produced drill cuttings are contaminated by hydrocarbons, and other chemical additives. The produced drill cuttings are hazardous for environment as they contain polycyclic aromatic hydrocarbons and undesirable heavy metals. Presently, various oil and gas operator companies in Yemen and other parts of the world dispose the drilling wastes in excavated pits or landfill sites. It is not acceptable to deal with such hazardous substances in this manner. Other operator companies use thermal desorption technique as a separation method. This method still has many disadvantages. Therefore, it is vital to search for sufficient and efficient technologies and processes to treat oil-based drilling wastes as the existing methods in use cannot be considered as a viable solution to eliminate the environmental damaged caused by contaminated drill cuttings. This paper review three existing experimental methods of extraction that have significant total organic carbon removal efficiency and highlighted factors that effect on the extraction efficiency. They are; supercritical water oxidation, superheated steam extraction, and supercritical carbon dioxide extraction. The stated experimental studies -have shown promising results and efficiency in extraction of carbon content and are considered environmentally friendly.