Ecological risk associated with the onshore hydrocarbon deposits exploration

Oil and natural gas exploration is performed using geophysical methods and drilling works. In areas initially identified as prospective for the occurrence of accumulation oil or natural gas based on the analysis of geological data carried out geophysical surveys. The aim of this works is to identify geological structures that could constitute hydrocarbons traps. In the case of finding the appropriate structures, the next stage of exploration work is drilling well for further recognition of the structure. These works allow to explore not only the geological profile but also the physico-chemical properties of drilled rocks and reservoir fluids. Geophysical (mainly seismic) surveys and drilling works can affect the individual elements of the environment: the atmosphere, underground and surface water, ground surface and land and rock environment in different degrees. In order to estimate the risks, threats to all elements of the environment related to the prospection of hydrocarbon deposits have been analyzed (seismic and drilling works). Environmental risk is estimated based on a modified methodology contained in the norm PN 18002. For risks associated with the exploration referred to the consequences of adverse events in relation to the individual elements of the environment and the frequency thereof (by determining the probability of their occurrence). The risk was estimated by multiplying the weight of the likelihood of adverse events weights and consequences. Risk evaluation, indicating danger tolerated, acceptable and unacceptable was also evaluated