The Environmental Impact of Drilling Sludge and Ways of Their Utilization

Abstract

Drilling sludge formed in the process of drilling wells using a drilling agent on a hydrocarbon basis looks like soft pasty mass of black color, with a distinct smell of petroleum products. Oil-based drill sludge has a high oil and chloride ions content, identified excessive concentrations of chromium 2.67 times. According to the degree of accumulation of heavy metals, that were distributed in the following order: manganese (Mn) > zinc (Zn) > copper (Cu) > chromium (Cr) > lead (Pb) > cobalt (Co) > arsenic (As) > mercury (Hg) > cadmium (Cd). The results of the particle size distribution indicate a significant proportion of physical clay, which peaks for the silt fraction – 63.60 %. During the study of the waste drilling agent was found that it includes oil products which reached level of 9000 mg/kg, while the hydrogen index refers to a neutral medium – 6.5 pH. The evaluation of the toxic effect of drilling waste according to the test-results has an acute toxic effect on the environment (hazard class IV). The significance of the research indicates the relevance of environmental assessment of drilling waste for the optimal choice of their subsequent disposal.

Keywords

• toxicity
• industrial waste
• petroleum products
• neutralization
• drilling sludge
• hydrocarbon-based solution