Geoinformatika 2020; 1(73) : 56-63
УДК 553.982
MODELING OF FILTRATION PROCESSES IN HETEROGENEOUS ANISOTROPIC GAS-BEARING RESERVOIRS ABSTRACT
M.V. Lubkov, O.O. Zaharchuk
Poltava Gravimetric Observatory of Institute of Geophysics of Ukraine National Academy of Science, 27/29 Mysoedova Str., Poltava 36014, Ukraine, mikhail.lubkov@ukr.net
Purpose. Nowadays there are important problems of increasing efficiency of development and exploitation of gas deposits. There are problems associated with the growth of gas production in heterogeneous anisotropic reservoirs, increasing gas recovery, achieving economic efficiency and so on. In this situation, there are popular methods of computer modeling of gas productive reservoirs, because they allow getting information of the structure and characteristics of the gas reservoir, the distribution parameters of permeability and other important factors in it. They also allow evaluating and calculating uncertainty arising from the lack of information about the gas reservoir properties outside the well. Currently there are many methods of computer modeling, allowing solving various practical problems. Another hand there left some problems related to the accuracy and adequacy of simulation of heterogeneous anisotropic permeable collector systems in real conditions of gas deposits exploitation.
Design/methodology/approach. On the base of combined finite-element-difference method for solving the nonstationary anisotropic piezoconductivity Lebenson problem, with calculating of heterogeneous distribution of permeable characteristics of the gas reservoir, we carried out modeling of filtration processes in heterogeneous anisotropic gas reservoir in close and remote zones of producing well.
Findings. The results of computer modeling show that intensity of the filtration process in vicinity of gas production wells depends essentially on its location in the anisotropic reservoir, both in the near (Ra < 500 m) and remote (Ra > 500 m) zones of acting well. Moreover, the effect of anisotropy of the gas permeability in the close zone is greater compared to the effect in the remote well zone. The obtained results show for effective exploitation of anisotropic reservoirs it is necessary to place producing wells into the local areas with relatively low anisotropy of the gas reservoir permeability, especially to avoid places with shear anisotropy. Before installation of production wells in anisotropic gas reservoirs, it is necessary to carry out a systematic analysis of the surrounding anisotropy of the reservoirs with the purpose to ensure effective filtration processes around these wells. We have sowed that installation of productive wells in diagonal direction relatively the main anisotropy axes of the gas reservoir permeability improve gas filtration processes. Obviously, the best conditions for gas production processes in any practical case we can achieve due to optimal selection of all anisotropic filtration parameters of the gas reservoir.
The practical significance and conclusions. One can use obtained results for practical geophysical works with a purpose optimizing of gas
production activity in heterogeneous anisotropic reservoirs. In further it is interesting to use presented method for more detailed investigation of heterogeneous anisotropic gas-bearing deposits.
Keywords: computer modeling, anisotropic filtration processes, gas reservoirs.
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Receive 20.02.2020