Środowiskowe aspekty produkcji gazu ziemnego z niekonwencjonalnych złóż

Abstract

Environmental aspects of unconventional gas production.A b s t r a c t. Prospecting and production of natural gas from unconventional gas fields is performed through regular diameter, multi-bottom wells a few hundred to a few thousand meters deep. Due to their character, drilling such wells creates a potential threat for all environmental elements. The degree of potential environmental impact depends on numerous factors, the most important of which include: location of a rig, level of urbanization of an area, sensitivity of environment to pollution, as well as type and scope of operations stimulating flux of hydrocarbons to the wells. Drilling natural gas prospecting and production wells involves a number of technological operations which generate significant noise emission, air pollution with exhaust gas from driving engines and significant quantities of waste, especially waste from matrix acidizing and fracturing. The paper presents results of analyses of noise emission and air pollution generated by drilling machines selected for drilling deep prospecting and exploitation wells. The investigations were focused on rigs Skytop TR-800, National 110UE and IRI-750/Cabot, which differ in technical and technological parameters. The obtained results confirmed differences in environmental impact of individual types of rigs. The differences appeared related to distinct directional acoustic characteristics, oscillating noise level and magnitude of air pollution emissions. Figs. 1 and 2 show distribution of noise level A in proximity of rig IRI-750/Cabot and Skytop TR-800 during hoisting operations, and Fig. 3 — exemplary distributions of NO2 and H2S concentration in air near the rig during drilling operations. Types and quantities of waste generated in drilling natural gas wells to the depth of 3000 m and accompanying hydraulic fracturing of rocks, are also presented in the paper.