Many journalists meetings with the leadership of the Cabinet of Ministers of Ukraine , the Ministry of Energy and Coal Industry of Ukraine , National Academy of Sciences of Ukraine have repeatedly treated the issue of energy security of Ukraine and prospects of rapid increasing the extraction of shale gas (hereinafter – SG) from the oil and gas structures of the Eastern (Uzyvska site) and Western (Olesky site) regions.
Expert and analytical research of specialists from the Institute of Geological Sciences, Institute of Telecommunications and Global Information Space , Institute Geochemistry of Environment National Academy of Sciences of Ukraine and the National Institute for Strategic Survey under the Administration of President of Ukraine, the Ministry of Ecology and Natural Resources of Ukraine showed that the extraction from the impermeable shale deposits the hydrocarbon resourses (shale and tight gas) ( depth 3.5 – 5.5 km ) should be connected with the industrial implementation the developed in USA about 20-30 years ago of industrial level the fraking technology ( hereinafter – the FT ), but with its ecological and technological adaptation to the parameters of oil-gas-waterbearing structures of Ukraine.
Physical and technological content of the FT is associated with the creation in the impermeable and compressed water-gas-saturated rocks the technogenic permeable fractured and chemically active space. This is achieved by drilling the clasters of the horizontal or inclined boreholes (about 6-10 boreholes / km.square) with its next perforation for the making (fraking) space of active development the permeable splits. Following injection in the area of fracking splits (AFS) 8-15 thousands tons toxic man-made solutions (surface acvtive substances, sand etc.). About 25-35 % of these mixtures are remained in the AFS as the source of ecological danger for underground hydrogeosphere.
Realized expert analytical assessments (academician Lyalko V.I., academician Shestopalov V.M., PhD Yakovlev Ye.A., сorresponding member Trofimchuk A.M., PhD Krasovskiy G.Y., candidate of geological- mineralogcal sc. Yakovlev V.V., doctor of geological sc. Asimov A.T., doctor of geological sc. Shekhunova S.B. etc.) have shown that in the gas-oil bearing structures within the Eastern and Western regions of Ukraine FT is able to form a threat of the regional pollution of artesian aquifers containing the fresh drinking and mineral medical water.
Analysis of remote sensing data (RSD) for evaluation the territorial specjfjc density of regional tectonic disturbances as potential paths upward migration of toxic residues of technological solutions in the AFS demonstrated the possibility of forming two main mechanisms of the process:
- Formation of hydraulic-filtrative contacts AFS with permeable tectonic zones; conducted geospatial assessments is showing that the density of linear fractures of AFS is the 4-6 times more comparatively with the background density of lineaments according to RSD. As a result, a high probability can be created for penetration of technology toxic contaminants in tectonic zones are penetrating to upper bedded horizons of drinking and mineral medical water. The estimated time of migration is 5 – 50 years , coinciding with individual cases of pollution of groundwater and surface water sources in the U.S. during 20-30 years the industrial implementation of FT;
- Slow lateral diffusive-convective rises the technological solutions residues from fractured space AFS due to their low specific density (1000 kg/m.cubic) comparatively with mineralized pore water (300-400 g /l), whose specific density is 1200 kg/m.cubic.
Approximate time of reaching the freshwater horizons is about 300-500 years. But the movement can be essentially accelerated due to creation of the water-gas emulsion.This process is able to cover the whole area of SG production.
Comparison of the volume the porouos water of the rock massif above AFS and potential pollution ability of remnant technogical solutions is showing the high risk of long-term contamination of underground hydrogeosphere.The experience of toxic liquid wastes injection in the deep horizons (U.S., Russia, Ukraine) is witnessig about the same (the viskosity of the gas almost 1,000 times less than water and technological solution one).
When Ukrainian experts due to supporting by SHELL were familiarized (September 2013), in the field conditions of Pennsylvania state with the technology of shale gas extraction and the composition of the local environmental protection measures , it was established that at the regional level in the U.S. operates over two hundred regulatory documents, taking into account ecological , technological and socio- economic parameters of FT. Unfortunately, Ukrainedoes not have the developed complex of the legal acts to ensure the safe of FT for SG production within oil-gas-waterbearing geological structures that are associated with a high-energy and dangerous hydrogeochemical impacts on deep horizons of geological enviroment.
Also, while interacting with experts of USA Environmental Protection Agency and members of the public it was established that in the U.S. within the territories of 35 states for three years is realized a program of assessment the changes in the ecological status of groundwater and surface water in areas of long-term industrial production of SG by drilling control wells (160 thousand) and testing of surface water bodies (180 thousand units).
Performing these works mainly due to the increasing number of complaints of local people to the deteriorating quality of surface and ground water sources and ecological condition of the landscape area extraction SG.
Comparative analysis of environmental threats connected with industrial implementation the FT within SG deposits in U.S. and Ukraine allows to reach the following preliminary conclusions:
- Structurial geology and hydrogeomighration conditions saline and fresh groundwater in the fields of SG in Ukraine is more complex due to more higher tectonic disturbance including the active development of salt domes, the presence of in vivo filtration connections of mineralized horizons and fresh groundwater in the form of sites their pollution by toxic chemical elements (mercury, arsenic , copper , iodine etc.).
- Implementation of FT in Ukraine requires the outstripping elaboration a regulatory documents for its industrial use.
- Taking into account the risk of highly probable contamination the deep layers within large areas of the geological environment during industrial implementation of FT, the dangers of toxic compounds migration to the source of drinking water supplying system, technogenic development of seismic shakings and deformation of the surface, it seems expedient:
- elaboration of the state program of substantiation the ecological ,technological stability and socio -economic efficiency the exploitation of shale gas (remote sensing and analysis of materials the gas-geochemical survey in areas of search and extraction of SG in order to separate the environmentally safe areas, creating geological and economic models and so on.);
- scientific creation of criteria for maximum allowable ecological and man-made changes in oil and gas structures using FT in order to prevent contamination of underground layers of fresh drinking and mineral medical waters;
- perfection of the existing monitoring system including gas-geochemical,landscape geochemical, hydrogeological, geophysical and geodetic parameters of geological environment in the areas of environmental impact of shale gas extraction.