Ślady ropy naftowej i gazu ziemnego w reionie Lubin-Kożuchów-Wschowa

Abstract

TRACES OF OIL AND NATURAL GAS IN THE LUBIN-KOŻUCHÓW-WSCHOWA REGIONIn the southwestern part of the Fore-Sudetic monocline in the region of Lubin-Sieroszowice-Kożuchów, many boreholes revealed traces of oil and natural gas. These traces are connected with Triassic and Permian sediments. Most of these traces, especially the most intensive of them, have been observed in the Zechstein, particularly in the principal dolomite of the Stassfurt cyclothem and in the dolomites and anhydrites of the Werra cyclothem. In the present paper the author discusses the appearance of these traces on the background of the geology of the region, and presents the results of laboratory examinations of the bitumina found.Direct traces of so-called "live" oil in the cores, in the shape of drops found in fissures or cracks, were discovered in the following bore-holes: Sobin, Biedrzychowa, Radwanice B, Przesieczna, Dzikowo, Wschowa 1 and Wschowa 3. In all these holes the traces were connected with the Werra cyclothem represented by anhydrites and dolomites. Moreover, in bore-hole Wschowa 1 there were also discovered traces of oil in the principal dolomite of the Stassfurt cyclothem. In more than 15 bore-holes that were sunk into the Zechstein series of anhydrites and dolomites assigned to the Stassfurt and Werra cyclothems, the cores gave off a fairly strong smell of crude oil. The traces·found made the author select from 8 bore-holes 180 spot samples and to subject them to laboratory tests. From the selected samples the bitumina were extracted by chloroform using the Soxhlet apparatus.During drilling, traces of natural gas were observed in the boring mud of several bore-holes. The greatest amount of bitumina (0,342%) were found in samples from bore-hole Dzikowo. In the samples collected from the remaining bore-holes the bitumina content was from 0,004-0,108%.In view of the fact that detailed examinations embraced but a small area of the Fore-Sudetic monocline, it would be difficult to draw regional conclusions at present period. This is probably going to be possible after further bore-holes have been sunk in the extension of the discussed zone both towards NW and SE. Even so, the direct traces of oil and gas discovered heretofore should stimulate a more intensive exploratory research for oil and gas in the entire area of the Fore-Sudetic monocline, not only in its central part where these traces have mainly. been encountered in bore-holes drilled in the search for other woeful minerals.