Zagadnienie szczelinowatości i pojemności zbiorników ropnych w skałach węglanowych

Abstract

FISSURING AND BULK OF THE PETROLEUM BASINS IN CARBONATE DEPOSITS Summary After a short introduction dealing with the beginings of studies on the fissuring of rocks in the U.S.A. the author sums up all opinions on fractured carbonate rock basins, pronounced by the Russian, American, Polish and other investigators. It appears that the works conducted in the WNIGRI (Leningrad) by the team under the guidance of professor E. Smiekhov are at the head of the theoretical research works, at present. Hence, about 100 scientific papers are a results of these works. Two main types of fissures have been distinguished as follows: primary, diagenetical fissures and secondary tectonical fissures. As a rule, both types occur in the rocks. The following are types of basins distinguished by E. Smiekhov: purely fissured, cavernous and stylolitic types. Here belong also various combinations of these types with the porous ones, (together 8 types). Opinions on fissured basins are being intensely discussed at present. According to the WNIGRI’s opinion the void spaces belonging only to the fissures represent scarcely some tenths of hundredths of one per cent in the total bulk of rocks. At a depth below 1000 metres here are found microfissures only; as a rule, their part is restricted to the filtration of fluids and gases through the rock pores. The second view, represented rather by the co-workers of the petroleum industry centres and of the industrial institutes in the Soviet Union and in Poland, is based on the fact that the fissure volume of a basin is also determined by microfissures which are able not only to filtrate, but also to accumulate fluids and gases. In addition, the author gives some data from his practice and from literature that prove the opinions mentioned above. To the end of his paper the author draws some conclusions concerning calculation method of resources in fissured carbonate rock deposits, and recommends to use, besides thin section method, also macroscopic examination of drill cores, according to the method elaborated by T. Birecki in the Petroleum Institute.