Geological heterogeneity and distribution of filtrational and capacitor properties in a section of productive thickness sheshminian strata of the SVO field

In present work lithologic features and filtrational and capacitor properties (FCP) of rock-reservoir sheshminian strata of the of superviscous oil (SVO) field are investigated. The reservoir according to the description of a core material presented by non-uniform petrosaturated sandstones in various degree with prevalence caicium and clay differences. According to tabular data FCP and physical properties of sandstone layer are studied; the tendency of deterioration in efficiency of layer down a section is established: decrease in coefficients of open porosity, vertical permeability and oil saturation. Curve variations FCP on a well No. 1 section are for descriptive reasons constructed. Major factor of deterioration FES down section, most likely, increase in content of carbonate material. In addition correlation connection between filtrational parameters is established. 2 groups of the interconnected parameters with correlation coefficients more than 0,5 are allocated: 1) porosity- calcareousness-vertical permeability; 2) oil saturation calcareousness. Based on results of the previous researches of sheshminsky sandstones, authors have made assumption that the deterioration tendency down a section is explained by migration of reservoir waters from underlying deposits of the Sakmarian age.
Materials and methods
Tables with petrophysical researches of core material of bitumen sandstones of the Ufimian stage. Plotting of variations of filtrational and capacitor properties and oil saturation on a section of wells
Results
1. Reservoir is presented by sandstones with various extent of cementation and impregnation by superviscous oil 2. According to the laboratory analysis of a core material, strata is characterized by strong degree of heterogeneity at the microlevel 3. Correlation communications between collection properties are revealed, 2 groups of the interconnected parameters are allocated: 1 group - open porosity, vertical permeability, calcareousness; The 2nd group - calcareousness, oil saturation. 4. Curves of variations of collection properties on a section are constructed; the deterioration tendency down a section of the sheshminian strata is established 5. According to data of the previous researches one of the possible reasons of deterioration FCP is migration of reservoir waters from the underlying horizon. Such phenomenon and in the studied section of this field is quite admissible.
Conclusions
Despite uniformity of lithologic structure of productive thickness of sheshminian sediments, reservoir is non-uniform on distribution of physical properties (porosity, permeability, oil saturation, calcareousness). As show results of the previous researches [2,5] and in the present work as the most productive a roofi g part of oil strata, unaff ed processes of a katagenesis (epigenetic cementation); this circumstance needs to be considered at allocation of high-permeability intervals for involvement in development of hydrocarbons.