Ideal formation factor determination method, hydrocarbon saturation determination method and porosity effectiveness evaluation method

Abstract

The invention discloses an ideal formation factor determination method, a hydrocarbon saturation determination method and a porosity effectiveness evaluation method. The ideal formation factor determination method includes: acquiring permeability K of a rock sample according to a rock physical experiment; acquiring an ideal formation factor F* according to a corresponding relation between the permeability K and the ideal formation factor F*. The ideal formation factor determination method, the hydrocarbon saturation determination method and the porosity effectiveness evaluation method have the advantages that under the condition of poor porosity-permeability relation, the ideal formation factor can be directly calculated according to the permeability, porosity effectiveness evaluation and hydrocarbon saturation determination are further realized on the basis of the ideal formation factor, and accordingly precision in recognition and quantitative evaluation of hydrocarbon reservoirs can be realized, and the foundation is laid for establishment of petrophysics based reservoir parameter evaluation standards in the future.

Description

Technical field [0001] The invention relates to the field of petroleum exploration, in particular to a method for determining ideal formation factor, a method for determining oil and gas saturation, and a method for evaluating pore effectiveness. Background technique [0002] In 1942, Archie published the famous Archie formula based on rock physics experiments, which established the position of porosity in logging quantitative evaluation of hydrocarbon saturation and played a huge role in logging quantitative interpretation. The classic Archie formula is: [0003] Formula 1) [0004] I = R t R o = b S w n Formula (2) [0005] Where F is the formation factor; R o It is the resistivity when the rock sample is completely saturated with brine, the unit is Ω·m; R w Is the resistivity of the brine in the Archie formula, the unit is Ω·m; φ is the porosity of the rock sample (decimal mark); a is the lithology coefficient; m is the cementation index or por...

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Problems solved by technology

[0006] With the deepening of oil and gas exploration, there are fewer and fewer pure sandstones that meet the conditions of the Archie formula. Factors such as the electrical characteristics of non-Archie rocks, the influence of pore structure, and the influence of mud will lead to formation factors and oil and gas saturation determined by the Archie formula. Inconsistent with the electrical characteristics of fully water-bearing rocks, the effectiveness of pores is questioned, which seriously affects the identification and quantitative evaluation of oil and gas layers, and is not conducive to oil exploration

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