RISK ASSESSMENT OF DRILLING MUD AND CUTTINGS FROM OHAJI WELLS X AND Y, NIGER DELTA

Drilling muds, commonly used in oil and gas industry in the Niger Delta often contain toxic heavy metals that poses significant environmental risks. They are capable of contaminating the soil and groundwater via leaching into soil and groundwater, especially in the Niger Delta where rainfall is high. This study seeks to appraise the risks connected with heavy metals in drilling mud and cuttings in onshore oil operations so as to ensure that disposed drilling mud do not pose danger to environment. The results obtained from this study show that mean concentration of Fe (2.99 – 494.36 mg/l), Cu (0.0 – 0.29 mg/l), Zn (0.03 – 3.17 mg/l), Pb (0.01 – 1.68 mg/l), Ni (0.0 – 1.82 mg/l), Cr (0.0 – 0.18 mg/l) and Mn (0.16 – 2.30 mg/l). Apart from concentration of iron that was high, all parameters were below the permissible limits. These heavy metals though present in small amounts may coalesce resulting to combined effects that may be detrimental to health and environment. The study validated that perceptivity of the ecological implication of heavy metals in spent drilling muds and cuttings is crucial for environmental sustainability