New Approach for Unconventional Reservoirs Rock Typing Characterization: Egyptian Unconventional Gas Reservoirs

Abstract

Mohamed Ahmed Fathy Omran and Attia Attia

The main objective of this research is to enhance unconventional reservoir characterization by developing and/or establishing new correlations through using a real case study of unconventional shale gas reservoir called Upper Safa formation that located in the western desert of Egypt. In addition to describing its geochemical and petro physical reservoir rock and fluid properties more consistently through a full integration among unconventional rock parameters as permeability, porosity, tortuosity, surface roughness, adsorption, type of kerosene, level of maturity, total organic carbon content, and etc. The results showed that Upper Safa formation is a shale gas unconventional resource play that consists mainly of Kaolinite clay and other mixed clay types. Geochemical pyrolysis analysis is used to confirm the presents of Kerogen type III as a shale gas potential reservoir. Interpretation analysis has been used also to confirm the presence of hydrocarbon potential in shale reservoirs depend on the readings that indicating most of shale play. Hence, after applying the surface roughness factor to Total gas in place equation through multiplying the (1-0.4) factor to volume of adsorbed gas in place to get new more accurate value for total gas in place TGIP’ equals 9.12 BCF. Moreover, brittleness ratio average value equals to 50% brittleness. However, TOC results which are obtained within the ranges of very good petroleum potential according to Rock Eval pyrolysis from 2% to 4% TOC. Hence, the results obtained from using of Dykstra Parson permeability variation, Upper Safa formation is highly heterogeneous formation which is very close to 100% heterogeneous formation, as any unconventional shale reservoirs due to the huge variation in the permeability ranges from milli-Darcy ranges to nano-Darcy ranges. Thus, several conventional and unconventional rock typing methods have been applied to overcome this zonation problem, besides establishing a new approach for unconventional reservoirs rock typing

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