Treatment Efficiency of Drill Cuttings Using Thermal Desorption Technology

Aim: The aim of this study was to analyze and determine the treatment efficiency of drill cuttings using the Thermal Desorption Technology.

Study Design: Drill cuttings were obtained from a work-over drilling operation with samples obtained at a depth of 2,750m from a typical well for this baseline study. The aim is to analyze the physical and chemical characteristics of the drill cuttings in a laboratory before and after the thermal desorption processes. A second drill cutting sample from another field location at the same depth of 2,750m was used for comparison during the analysis.

Place and Duration of Study: Port Harcourt, Rivers state, Nigeria (Laboratory analysis was done at Anal Concept Ltd, Port Harcourt, Rivers state, Nigeria and the thermal desorption unit is situated at the Initiates Plc, Etche LGA, Rivers state, Nigeria).

Methodology: A representative sample feedstock of cuttings was collected before and after the thermal treatment. The drill cutting sample was taken from a mixing tank by using a cup and auger. The samples of the cuttings were made for each case of the grab samples, and the samples later transferred into 500mL glass bottles. The sample contaminants were analyzed in a chemical laboratory using standard methods for determining the pH level, Electrical Conductivity, Moisture Content, Organic Pollutants and Heavy Metals.

Results: The result showed significant reductions in all the pollutant concentrations after the drill cuttings were treated with the Thermal Desorption Unit. Moisture Content (MC) and the Total Petroleum Hydrocarbon (TPH) decreased significantly by 86% and 93% respectively. The concentration of the combination of Benzene, Toluene, Ethylbenzene and Xylene (BTEX) reduced drastically by 98% and the heavy metals concentration levels were also reduced after treatment with the TDU. Also, the laboratory analysis result of the treated drill cuttings shows that the pH level, Electrical Conductivity, Moisture Content, Organic Pollutants and Heavy Metals concentrations did not exceed the recommended Department of Petroleum Resources (D.P.R) limits.

Conclusion: This research reveals that the thermal desorption technology is the most economical, efficient and environmentally friendly method of waste management due to its contaminant removal efficiency. This method enhances product recovery and subsequent recycling which helps to reduce environmental impact and prevent economic losses.