ASSESSMENT OF THE RESIDUAL CONTAMINATION AT THE DRILLING SITES OF THE ROSTOVTSEVSKOE FIELD

Abstract

The relevance of the research is caused by the long-term impact on environmental objects (in particular, soil) of exploration well sites drilled in the 80–90s of the 20th century on the territory of the continental part of the Russian Arctic. The persistence of pollution is primarily due to the low self-purification capacity of northern ecosystems. Assessment of the environmental hazard of contaminated soils and industrial and economic waste using the example of the Rostovtsevskoe field will allow considering the possibility of implementing measures to restore ecosystem components. The aim of the work is to assess the current state of the soil cover at the Rostovtsevskoe hydrocarbon field. Object of the research is the territory in the area of 25 wells of the Rostovtsevskoe hydrocarbon field (Yamal Peninsula, the Yamal-Nenets Autonomous District) drilled in the period from 1986 to 1989. Methods. The set of studies included the sampling and laboratory analysis of 103 samples of background and contaminated soils from the upper (0–10 cm) and lower (10–20 cm) horizons. Particular attention was paid to the study of the anionic-cationic composition, the content of metals, oil products, phenols, anionic surfactants. Results. The fact of direct soil contamination with oil products, barium sulfate, zinc, lead and other metals has been established. In addition, anthropogenic impact led to the suppression of natural inhomogeneities of the geochemical field and the formation of a homogeneous near-surface physicochemical environment. Within the soil layer, a redistribution of compounds and elements is noted, the content of which either did not change (anionic surfactants, arsenic), or significantly decreased (chloride ion, ammonium). According to the total pollution index the content of harmful substances near the 23 out of 25 researched drilling sites is characterized as extremely dangerous. The main contribution to the total pollution index is made by oil products.

Keywords

• residual hydrocarbon pollution
• ecology
• anthropogenic impact
• natural geochemical field
• drilling sites
• oil products in the soil
• restoration of arctic ecosystems