A. Koval
Ukraine, Kharkiv, UKRNIIGAS

V. Benko, T. Dovzhok
Ukraine, Kyiv, SC "UKRGASPRODUCTION"

GEOETHICAL PROBLEMS OF DEVELOPMENT OF MINERAL RESOURCES IN CARPATHIAN OIL- AND GAS-BEARING REGION

Geoethics is a modern doctrine having a profound philosophical sense, including an ecological aspect and determining the attitude of the man to noosphere, development of mineral- and raw-material resources and protection of the geological medium. Geoethics is of a special urgency due to human activities in the field of oil and gas production having an ever-growing character. While exploring, producing oil and gas, we penetrate into deep-lying strata of the lithosphere and thereby disturb its tectonic, geothermal, geophysical and geochemical balance within a self-governing geological system.

Among chemical compounds contaminating soil and water, and adversely affecting the environment are oil products and phenols. Specifically, poly-cyclic aromatic hydrocarbons are the most widespread cancerous substances [1]. The specific weight of natural cancerous substances in the soil and water is small and does not appear to be a serious hazard to animals. The concentration of oil products in uncontaminated rivers and lakes varies between 0.01 and 0.2 mg/l [2], and the content of phenols does not exceed 0.015 mg/l [3] and may be considered as a natural background. Super background concentrations of cancerous pollutants can occur to some extent by leakage of oil and oil processing products as a result of mining-industry activity and exploration.

Lately, the Carpathian Region of Ukraine is characterized by the trend to the development of new or earlier deserted, but still promising oil- and gas-bearing territories. In this case, we, on the one hand, face the negative consequences of prospecting and development of oil, gas and sulfur fields caused by actions taken by our predecessors and, on the other hand, we are on the brink of new mistakes connected with rapid changing of development level of productive forces and establishment of new social relations.

The study of the ecological condition of right tributaries of Dniester running along the Carpathian oil and gas producing region of Ukraine performed by the specialists of the Institute of Geology and Geochemistry of combustible minerals has shown that the water of these rivers is greatly contaminated by phenols and oil products [4]. Their concentrations are more than the maximum permissible concentrations for the water of cultural and everyday purposes in 2.3-15.6 and 9-54 times, respectively.

Such high concentrations of the components mentioned above are, undoubtedly, a consequence of the Carpathian mining complex activity. The hazard of this phenomenon at the conditions of the mountain relief and insufficient self-treating potential of Dniester, even in the upper part of its basin, gains ground owing to the ability of the oil products and phenols to migrate a great distance away.

This is confirmed by the results of the researches performed by the specialists of the Ukrainian State Geological and Prospecting Institute aimed at studying the technogeneous influence of oil well drilling on the condition of the near-surface hydro-lithosphere [5]. On May 1997 an anomaly of oil products and phenols in the soil bed at a depth of 0.2 m had been determined at a pilot ground not far from the well Blazhevska-11. The anomaly front was located at a distance of 300 m away from the well. The anomaly intensity in some places amounted to as much as 193 and 1110 background values concerning oil products and phenols, respectively. At the same time contamination by oil products and phenols has not been revealed within the well’s region at depths of 0.8-2.0 m. The reason is that soils - formed on ashen-diluvial clay, loams and rarely sandy loams at a heavy gradient of the land - are characterized by low filtration but high sorption features.

The results of the investigations mentioned above should be estimated with a caution as nowadays the Folded Carpathians Region has again become one of the prospective lines of development. The most important role in the Ukrainian sector of the Folded Carpathians belongs to Skybian, Krosno, Duklya and Chornogorsk zones which, lately, are preferably considered as overlapped, folded and overthrust structures. At the same time, the most promising Krosno zone distinguished for wide spreading of Oligocene and Lower Miocene deposits of Krosno facies still arises disagreements as regards its origin, tectonic classification, boundaries, internal structure and zoning in connection with prospects of its oil- and gas-bearing potential.

For all that, two significant geoethical moments (problems) come about. The first lies in the fact that the oil and gas production industry is directed to discovering new large- and medium-size fields, enlarging the prospected reserves, providing the industry with a bulk of work for a long period of time and obtaining substantial incomes. At the same time little attention is given to small, as it is considered nowadays, noncommercial hydrocarbon accumulations many of which have already been discovered at depths of 1000-1500 m. It should be taken into account, therewith, that the geological structure of the Folded Carpathians Region is complicate. Large structural traps of hydrocarbons are absent in the overlapped-folded stage and the character of bedding, lithofacial rock variation and the types of oil and gas traps in the para-autochthone at considerable depths, where great inflows are expected, are as yet poorly known. It may happen that there would be no considerable accumulations of oil and fuel gas (more than 3-5 million tons of conventional fuel) at great depths on account of high dislocation of the section, complicate fine-block structure and development of reservoirs with small filtrating-capacity parameters.

The history has shown that urging towards high rate of production and considerable reserves we often don’t take into account small fields, «dry» and marginal wells. Such fields and wells with little oil and gas influx, if not today, in some time may become a substantial source of energy for the nearest small settlements in the Carpathian region. Indeed, only then would rise the problem on developing reservoirs with little oil production rate amounting to 1t/day and small gas reserves with gas influx up to 500 thousand m³/day in several days then it rapidly falls. It is worth to think about this today and to regard such phenomena with attention.

While starting an extensive geological prospective work, we should not make the same mistakes as those made by our predecessors in the first half of the last century. They set up in the Krosno zone and left after short time of development many tens of small oil fields found in insufficiently investigated structures. The production was carried out in shallow holes and wells later being left. The signs of quality Carpathian oil still can be seen in some of them after expiration of tens of years.

Just this is the essence of the second geoethical problem that is bound up with ecology - pollution of the atmosphere, soil and surface waters by oil products as a result of completing drilling jobs without necessary liquidation arrangements in the wells.

The way out is to control all abandoned mining holes and wells located at oil and gas-bearing territories, to compile their summary cadaster, to determine wells with oil and gas showings and to inform the landowners about the presence of such wells at their territories.

According to geoethics our task is to learn how to impact the environment as less as possible, to prevent pollution of the litho- and hydrosphere by deleterious substances, to use rationally and save the mineral- and raw material resources of the Carpathians for our descendants at original conditions, if we are not ready to utilize these resources today.

Literature

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