UTJECAJ DEPRESIJE NA PRITOK VODE U BUŠOTINE U KARBONATNIM PODINAMA KARPATSKOGA PREDGORJA NA JUGOISTOKU POLJSKE

This paper presents an analysis of well testing data, performed with a Drill stem test (DST). The carbonate levels of Mesozoic reservoir rocks were investigated in the research area of the Carpathian Foredeep. Based on the results of 17 two-cycle DST reservoir tests, the dependence of the volume of the reservoir water flow rate from the Mesozoic carbonate reservoirs (Upper Jurassic, Lower Cretaceous) to the wells as a function of the mean depression of bottom pressure was researched in the selected oil exploration area in the Carpathian Foredeep basement, SE Poland. Using methods of statistical analysis, a satisfactory correlation between variables for power and the exponential model was found, and a weak correlation for the linear model was found. A decrease in the value of the reservoir water flow rate along with an increase in pressure depression was found for the Mesozoic carbonate reservoirs, which may indicate the occurrence of fractures and micro-fractures shortening under extreme pressure depression and blockage phenomena of fractures and cavernous pores in the perimeter area by solid particles (cuttings, salt, polymers, etc.).U radu je prikazana analiza rezultata testiranja bušotina metodom DST-a (engl. skr. od Drill Stem Testing). Istraživanjem su obuhvaćene razine karbonata u stijenama mezozojskih ležišta u Karpatskome predgorju. Na temelju sedamnaest testova ispitivanja ležišta metodom DST-a, provođenih u dvama ciklusima, istražena je ovisnost volumena protoka vode iz mezozojskih karbonatnih ležišta (gornja jura i donja kreda) u bušotine, a kao funkcija prosječne depresije zbog tlaka na dnu bušotine. Kao objekti istraživanja odabrani su oni smješteni upravo u naftnoj zoni Karpatskoga predgorja, na jugoistoku Poljske. Na temelju statističke analize uočena je zadovoljavajuća korelacija između varijabli potencijskoga i eksponencijalnoga modela te slaba korelacija kod linearnoga modela. Smanjenje pritoka ležišne vode iz mezozojskih karbonatnih ležišta, uz povećanje depresije, potencijalno upućuje na pojavu smanjivanja pukotina i mikropukotina uslijed prevelike depresije te na začepljivanje fraktura i šupljina nastalih otapanjem, do čega dolazi zbog krutih čestica poput krhotina, soli, polimera itd

Natural gas storages in Zechstein salt formations as an element of energy safety in Poland

Based on the formal and legal regulations, the need to increase the capacity of cavern underground gas storage in Poland is demonstrated. The author raised the problem of country's energy security, which is partly based on intervention reserves of energy carriers. A description of the state of actual storage capacities and strategic reserves of natural gas in Poland is presented, and the level of reserves is assessed based on applicable law. Focusing on the advantages of salt deposits in the context of underground gas storage, the author presents safe conditions for underground gas storage and the possible location of cavern underground gas storage in two prospective salt deposits: the Damasławek salt dome and the layer salt deposit of the Fore-Sudetic Monocline. The article draws attention to the complexity of the issue of geomechanical stability of caverns for underground gas storage, taking into account the type of deposit (layer/dome)

Wpływ parametrów reologicznych skał plastycznych Monokliny Przedsudeckiej na proces wiercenia otworów wiertniczych

Plastic rocks can creep, therefore the knowledge of the rheological properties of the drilled formations is an important element of the drilling process and when choosing borehole designs. These properties of plastic formations also influence the way in which appropriate drilling technology and drilling mud properties are selected. The article presents the effect of basic rheological parameters of salt from the Fore-Sudetic Monocline deposit on the drilling of boreholes in the mining area of KGHM Polska Miedź, which in the future can be used as a good drilling practice to improve the safety and efficiency of drilling.The process of drilling in plastic rocks may be hindered. Salt is a plastic rock and in the analyzed rock mass it is deposited at a considerable depth. The caprock exerts big loads on it, beside the tempe-rature in the deposit intensifies the rheological properties of the rock. The creep process causes that the borehole contracts, therefore the knowledge about the rheological properties of the drilled rock is very important for establishing the safe time in which the well may remain uncased. The paper is devoted to the influence of basic rheological parameters of salt bed in the Fore-Sudetic Monocline on the process of drilling of a borehole in the area of KGHM Polska Miedź as these data can be used in drilling practice in the future.Proces wiercenia otworów przechodzących przez skały plastyczne może powodować utrudnienia. Sól kamienna jest skałą plastyczną, w analizowanym górotworze zalega na znacznej głębokości, poddana jest dużemu obciążeniu wynikającemu z ciężaru nadkładu, niebagatelny jest też wpływ temperatury złoża, dzięki którym w skale spotęgowanie ujawniają się jej właściwości reologiczne. Płynięcie soli powoduje zaciskanie otworu, stąd ważnym elementem w procesie wiercenia jest znajomość własności reologicznych przewiercanej skały, dla ustalenia właściwej technologii wiercenia i wpływ na ustalenie bezpiecznego czasu pozostawienia otworu bez zarurowania. W artykule przedstawiono wpływ podstawowych parametrów reologicznych soli ze złoża Monokliny Przedsudeckiej na proces wiercenia otworu wiertniczego z rejonu KGHM Polska Miedź S.A, które w przyszłości mogą być wykorzystywane w praktyce wiertniczej