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Open access

Jakub Siemek and Jerzy Stopa

Abstract

This paper presents new analytical model of gas-water flow in coal seams in one dimension with emphasis on interactions between water flowing in cleats and coal matrix. Coal as a flowing system, can be viewed as a solid organic material consisting of two flow subsystems: a microporous matrix and a system of interconnected macropores and fractures. Most of gas is accumulated in the microporous matrix, where the primary flow mechanism is diffusion. Fractures and cleats existing in coal play an important role as a transportation system for macro scale flow of water and gas governed by Darcy’s law. The coal matrix can imbibe water under capillary forces leading to exchange of mass between fractures and coal matrix. In this paper new partial differential equation for water saturation in fractures has been formulated, respecting mass exchange between coal matrix and fractures. Exact analytical solution has been obtained using the method of characteristics. The final solution has very simple form that may be useful for practical engineering calculations. It was observed that the rate of exchange of mass between the fractures and the coal matrix is governed by an expression which is analogous to the Newton cooling law known from theory of heat exchange, but in present case the mass transfer coefficient depends not only on coal and fluid properties but also on time and position. The constant term of mass transfer coefficient depends on relation between micro porosity and macro porosity of coal, capillary forces, and microporous structure of coal matrix. This term can be expressed theoretically or obtained experimentally.

Open access

Jakub Siemek and Stanisław Nagy

Abstract

This paper discusses forecasts of energy carrier use with particular emphasis on the changing position of natural gas due to global climatic conditions and the increasing role of unconventional natural gas reservoirs. Allocation of natural gas resources in the world are discussed as well as global gas consumption and conditions for development of transport infrastructure and storage. The most important indicators of the energy security of countries are presented. The basic properties of unconventional deposits, and differences in the production/extraction of gas from the conventional and unconventional fields are given. In the paper are also discussed natural gas reserves in Poland, including possible non-conventional resources in the fields and issues of increasing the role of gas as an energy carrier in Poland in the background of the energy changes in Europe and the world.

Open access

Stanislaw Nagy and Jakub Siemek

Abstract

Natural gas from shales (NGS) and from tight rocks are one of the most important fossil energy resource in this and next decade. Significant increase in gas consumption, in all world regions, will be marked in the energy sector. The exploration of unconventional natural gas & oil reservoirs has been discussed recently in many conferences. This paper describes the complex phenomena related to the impact of adsorption and capillary condensation of gas-condensate systems in nanopores. New two phase saturation model and new algorithm for search capillary condensation area is discussed. The algorithm is based on the Modified Tangent Plane Criterion for Capillary Condensation (MTPCCC) is presented. The examples of shift of phase envelopes are presented for selected composition of gas-condensate systems.

Open access

Stanisław Rychlicki and Jakub Siemek

Abstract

In times of global crisis, there is a dynamic change in the European gas market. This leads to:

- decline or stagnation in demand for gas in the industrial sector;

- growing importance of unconventional natural gas;

- LNGmarket development especially in terminal condensing due to the availability of rawmaterials derived from unconventional gas deposits (USA, Canada);

- development of regasification terminals in Europe due to the possibility of receiving additionalmaterial;

- development of gas exchanges;

- development of cross-border gas pipeline connections leading to a progressive increase in the integration and linkages between markets;

- emergence of unconventional gas in particular shale gas and coal bed methane; in Poland the potential benefits from shale gas exploitation offering opportunities for its wider use in the energy sector;

- attention drawn to the role of unconventional gas, particularly shale gas;

- periodic surplus raw materials for the European market;

- renegotiation of long-term contracts for European customers;

- changes in contracts, which include the introduction of partial indexation to the exchange of gas markets, modification of TorP clauses, contract volume shift to later years;

- stronger bargaining position for the buyer of raw materials;

- possible long-term changes in the valuation of raw material in Europe;

- growing importance of short and medium-term contracts;

- changes in distributor relations - [client on national markets (meaning unclear)];

- activity of new entrants to the gas markets.

This paper presents the existing situation in the energy market in Poland in terms of the types of fuels used especially natural gas in the generation of electricity. It references Poland’s current energy relations with European countries, particularly with respect to the European Union. The analysis includes the size of unit energy consumption in selected EU countries. In addition, it reviews plans to build a major gas plant in Poland.

Open access

Andrzej Gonet, Stanisław Rychlicki, Jakub Siemek and Stanisław Stryczek

Open access

Monika Konieczyńska, Jan Macuda, Stanisław Nagy and Jakub Siemek

Abstract

This paper is a summary of results of environmental analysis conducted by PGI-NRI, AGH-UST within the monitoring of natural gas prospecting in unconventional deposits. All elements of natural environment were analyzed and on this basis the qualitative and quantitative impact of drilling and hydraulic fracturing of shales could be assessed. Special attention was drawn to the analysis of the physicochemical condition of post-reaction fluids, soil gas in the well pad area and drilling fluids. The results of analysis reveal that prospecting works do not create a significant environmental hazard. Some indices connected, e.g. with the noise climate lightly exceeded permissible values. Nonetheless, if extensive prospecting and production of shale gas are involved, the environmental studies need to be broadened to supplement this report.

Open access

Maciej Kaliski, Marcin Krupa, Stanisław Rychlicki, Jakub Siemek and Andrzej P. Sikora

Streszczenie

Artykuł poświęcony jest przeglądowi metod i sposobów estymacji kosztów otworów wiertniczych stoso- wanych na rynkach międzynarodowych (głównie na rynku północnoamerykańskim) oraz zawiera próbę aplikacji wybranej metody lub metod dla dostępnych danych odnośnie tego typu kosztów w basenach geologicznych w Polsce. Autorzy zajmują się wstępnym oszacowaniem przydatności tego typu estymacji dla modelowania i benchmarkingu efektywności prac poszukiwawczych i wydobywczych w Polsce. Na poziomie poszczególnych przedsiębiorstw poszukiwawczo-wydobywczych benchmarking i planowanie kosztowe są z reguły oparte na wypracowanych na różnorodnych złożach doświadczeniach i próbach optymalizacji technicznej i kosztowej całości procesu. W artykule zaproponowano i opisano wstępny algorytm do wyliczeń tych kosztów. Autorzy zwracają uwagę, że przydatność utworzonego na bazie równania (4) modelu do estymacji kosztów wierceń na podstawie głębokości docelowych formacji w Polsce jest mniejsza niż w na rynku amerykańskim, ale nadal bardzo wysoka. W przypadku analiz wykonywanych poza przedsiębiorstwami prowadzącymi prace poszukiwawczo- -wydob>|vcze może to być jedyne dostępne narzędzie do szacunkowych obliczeń kosztów otworów wiertniczych dla poszczególnych basenów geologicznych i docelowych głębokości.