ARTYKUŁY PRZEGLĄDOWE Podstawy metodyki poszukiwań, rozpoznawania i dokumentowania zasobów złóż w odniesieniu do złóż gazu ziemnego w łupkach gazonośnych

Abstract

Backgrounds of prospecting, exploration and reporting resources and reserves of shale gas deposits.A b s t r a c t. Gas in shales occurs as a constituent of rock and its resources can be estimated in a similar way as the metal content in ore deposit. The cutoff gas content in rock is the basic parameter defining deposit boundaries. It is proposed that the cutoffs in gas-bearing rocks are 2 m3 gas/t and 15-m deposit thickness. In case of lack of sufficient data, the deposit boundaries for resources estimation may be delineated in a defined distance from prospecting boreholes, supported by geophysical data, if possible. Discovered gas resources may be evaluated by volumetric methods. For reserve estimation, dynamic methods should be applied based on shale fracturing results. Following the stages of prospecting and exploration, decreasing uncertainty of the deposit resources/reserves evaluation may be expressed by D, C, B and A categories, or with the use of PRMS classification system.