Najgłębszy otwór badawczy w Polsce - Paszowa 1 (7210 m)
Abstract
THE BOREHOLE PASZOWA 1 - THE DEEPEST (7210 M) EXPLORATORY BOREHOLE IN POLAND
Summary
In 1980, the oil industry began to drill deep exploratory borehole Paszowa 1. The borehole, localized in eastern part of the Skole unit, 12 km north-cast of Lesko, the Polish Carpathians (Fig. 1), was finished in September 1984, attaining the depth of 7210 m. The area in which the borehole has been localized, belongs to still poorly known, despite of the fact that it used to be regarded as of high oil and gas potential by Polish geologists.
In the sixties a number of exploratory and prospecting drillings were made in area of the Skole unit by the Geological Institute and oil industry, in order to trace course of deep-seated folds and reconstruct character of basement beneath the Carpathians (boreholes Cisowa IG-1, Brzegi Dolne, and Kwaszenina) and deeper-seated perspective horizons of the Paleocene, Inoceramian Beds, and Lower Cretaceous (boreholes Słonne-Bachórzec). The exploratory borehole Cisowa IG-1 penetrated folded Flysch rocks and those of the Stebnica unit to encounter c. 260 m sequence of undisturbed autochtoneous Miocene, resting on folded Precambrian phyllites (S. Wdowiarz, S. Jucha, 1969). The exploratory borehole Kwaszenina IG did not reach the planned depth due to technical reasons, being stopped in the Inoceramian Beds. The borehole Brzegi Dolne IG-1, the deepest of the above mentioned (5440 m), also failed to penetrate strongly folded Inoceramian Beds (K. Żytko, 1965).
Further search in the Słonne -Wara region, carried out by the oil industry, resulted in finds of traces of oil and gas in the Inoceramian Beds (Wara) and very strong traces of brine with gas in the Jamno and Spas Beds (Lower Cretaceous in the Słonne area). The last of the boreholes, Bachórzec 1, penetrated the Carpathian Flysch to encounter direcly underlaying folded gray-green Precambrian phyllites, in which it was stopped (P. Karnkowski, 1977). In the seventies, the drilling works were accompanied by geophysical, mainly seismic surveys. On the basis of the surveys and previously completed drillings, the oil industry together with the Geological Institute, made a project of deep exploratory drilling Paszowa 1 (Z. Borys, K. Żytko, 1977). The drilling was aimed at reconstruction of deep geological structure of the Skole unit of the eastern Polish Carpathians and to evaluate its oil and gas potential.
Ten potential oil- and gas-bearing horizons have been identified and selected for further sampling in the borehole column on the basis of well logs and laboratory data. The lowermost of these horizons, situated at the depths 7050-7210 m, was found to be characterized by very strong traces of gas (CH4 up to70%), on the basis of results of Geoservices tests made in the course of drilling. Temperature recorded at the bottom of the borehole was equal 194°, and pressure was estimated at about 1250 atm. (that is why mud with specific density 2.15 g/cm3 has been used). The drilling Paszowa 1 has been completed despite of difficult geological conditions, initiating a new stage in prospecting in the Carpathians. In the same region, about 7 km from the borehole Paszowa l, there is at present made another deep borehole of the oil industry, Kuźmina 1. The drilling, designed to reach the depth of 7000 m, has already reach the 2800 m depth (Inoceramian Beds). It is aimed at testing the hypothesis of occurrence of so-called Borysław-Dolina folds, known to yield large amounts of oil and gas in the Soviet Union, in our country (S. Wdowiarz, 1969).
Summary
In 1980, the oil industry began to drill deep exploratory borehole Paszowa 1. The borehole, localized in eastern part of the Skole unit, 12 km north-cast of Lesko, the Polish Carpathians (Fig. 1), was finished in September 1984, attaining the depth of 7210 m. The area in which the borehole has been localized, belongs to still poorly known, despite of the fact that it used to be regarded as of high oil and gas potential by Polish geologists.
In the sixties a number of exploratory and prospecting drillings were made in area of the Skole unit by the Geological Institute and oil industry, in order to trace course of deep-seated folds and reconstruct character of basement beneath the Carpathians (boreholes Cisowa IG-1, Brzegi Dolne, and Kwaszenina) and deeper-seated perspective horizons of the Paleocene, Inoceramian Beds, and Lower Cretaceous (boreholes Słonne-Bachórzec). The exploratory borehole Cisowa IG-1 penetrated folded Flysch rocks and those of the Stebnica unit to encounter c. 260 m sequence of undisturbed autochtoneous Miocene, resting on folded Precambrian phyllites (S. Wdowiarz, S. Jucha, 1969). The exploratory borehole Kwaszenina IG did not reach the planned depth due to technical reasons, being stopped in the Inoceramian Beds. The borehole Brzegi Dolne IG-1, the deepest of the above mentioned (5440 m), also failed to penetrate strongly folded Inoceramian Beds (K. Żytko, 1965).
Further search in the Słonne -Wara region, carried out by the oil industry, resulted in finds of traces of oil and gas in the Inoceramian Beds (Wara) and very strong traces of brine with gas in the Jamno and Spas Beds (Lower Cretaceous in the Słonne area). The last of the boreholes, Bachórzec 1, penetrated the Carpathian Flysch to encounter direcly underlaying folded gray-green Precambrian phyllites, in which it was stopped (P. Karnkowski, 1977). In the seventies, the drilling works were accompanied by geophysical, mainly seismic surveys. On the basis of the surveys and previously completed drillings, the oil industry together with the Geological Institute, made a project of deep exploratory drilling Paszowa 1 (Z. Borys, K. Żytko, 1977). The drilling was aimed at reconstruction of deep geological structure of the Skole unit of the eastern Polish Carpathians and to evaluate its oil and gas potential.
Ten potential oil- and gas-bearing horizons have been identified and selected for further sampling in the borehole column on the basis of well logs and laboratory data. The lowermost of these horizons, situated at the depths 7050-7210 m, was found to be characterized by very strong traces of gas (CH4 up to70%), on the basis of results of Geoservices tests made in the course of drilling. Temperature recorded at the bottom of the borehole was equal 194°, and pressure was estimated at about 1250 atm. (that is why mud with specific density 2.15 g/cm3 has been used). The drilling Paszowa 1 has been completed despite of difficult geological conditions, initiating a new stage in prospecting in the Carpathians. In the same region, about 7 km from the borehole Paszowa l, there is at present made another deep borehole of the oil industry, Kuźmina 1. The drilling, designed to reach the depth of 7000 m, has already reach the 2800 m depth (Inoceramian Beds). It is aimed at testing the hypothesis of occurrence of so-called Borysław-Dolina folds, known to yield large amounts of oil and gas in the Soviet Union, in our country (S. Wdowiarz, 1969).