Toxicological Evaluation of Thermal Treatment of Drilling Waste from Shale Gas Exploration in Poland

The oil containing drilling waste is a worldwide environmental problem associated with oil and gas exploration. In Poland, the problem of the drilling waste has become important since starting of shale gas exploration. The results of thermal treatment of drilling waste from shale gas exploration are presented. It has been shown that organic content vaporized completely at temperature up to 500 °C. The main problem is high content of chloride, sulfate, sodium, potassium, magnesium in the waste and its water leachate. Toxicity tests confirmed that high salinity of the samples pose important risk for environment. Due to the high content of barium, the drilling waste may be utilized in production of cement with high chemical and heat resistance and opaque to X-ray. Thermal treatment process is a viable option for remediation of the drilling waste; however, the product of the process needs further treatment in order to remove its high salinity.