TITLE:
Environmental Impact Assessment of Heavy Metals in Surface Disposed Drilling Waste
AUTHORS:
Ullattumpoyil Nasir, M. Absi Saeed, S. Marzooq Yousif
KEYWORDS:
Petroleum, Drilling Waste, Heavy Metals, Toxicity
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.9 No.9,
September
30,
2021
ABSTRACT: Saudi Arabia has some of the biggest oil and gas reserves in the world, and has expanded its drilling
operations gradually to meet the global demand. Improper
handling of contaminated drilling wastes may cause serious negative environmental
impacts. The current study investigates the toxicological effects of heavy
metals in drilling waste by quantification
and developing different contamination indices. Solid and liquid samples from different drilling waste pits were
collected and analyzed for heavy metals. The average concentration varies
significantly and decreases in the order of Fe > Al > Sr > Mn > Cu > Cr > Zn >
Ni > Pb > Cd > Ag > Co. The spatial variation showed the highest concentration at
SDGM Site 1, West. Comparison of current data showed continental crust average
values within the specifications for most of the sites. For metals like Cd, Cr
and Cu, the concentration is higher than the continental crust value. Indices
such as pollution load index, modified degree of contamination etc. were calculated
from the available data. The contamination level for different site calculations showed nil to a very low degree of contamination.
Spatial variation of the contamination level indicated comparatively higher
values for sites UTMN-4 and SDGM-1 North, which indicates the necessity of
precautionary methods. The metal concentration in the pit water samples
exceeded generally accepted standards, if this water was to be discharged/leaked from the pit. The current study concluded
presence of different heavy metals in samples from the drilling waste pits,
whereas the degree of contamination is minute.