Environmental impacts of drilling mud and cutting wastes from the Igbokoda onshore oil wells, Southwestern Nigeria

Abstract

The environmental impact of exploratory wastes (drilling muds & cuttings) generated during the drilling of Igbokoda X and Igbokoda Y onshore oil wells, was studied by analyzing its total hydrocarbon (TPH), aliphatic hydrocarbon (AH), polycyclic aromatic hydrocarbon (PAH) using gas chromatography-mass spectrophotometry (GC-MS) method and metal contents using atomic absorption spectrophotometry (AAS). The aim was to determine their toxicity and possible impacts on their immediate environments of disposal. These drilled wastes generated from the drilling of Igbokoda X and Igbokoda onshore wells indicated an exceedingly very high values of AH compared with the values of PAHs in both the oil based and water based muds and cuttings respectively. These values of aliphatic is generally >5000 mg/kg in all oil based sample types analyzed for the drilled muds and generally >4000 mg/kg in all the sample types analyzed for the drilled cuttings. However, these values of the AH varied according to sample types with the water based drilled mud collected at the depth of 4121-10171 feet having values of >6000 mg/kg while the value in the water based drilled cuttings is generally