Formation factor determining method and oil saturation determining method

Abstract

The invention provides a formation factor determining method and an oil saturation determining method, wherein the formation factor determining method comprises the following steps of: selecting a representative series core of a secondary pore development low-percolation oil-gas layer; measuring and obtaining a core porosity degree phi, a percolation rate K, a capillary pressure curve Pc and an average pore-throat semidiameter, wherein the core porosity degree phi is used for reflecting conductive fluid volume and a conductive path in rock, and the conductive fluid volume and the conductive path in the rock are used as parameters for determining a formation factor F. The invention has the specific relational expression: determining the formation factor according to the conductive fluid volume and the conductive path, and factors a, b and c are obtained by calibrating core data. The invention introduces the conductive fluid volume and the conductive path as the parameters to determine the formation factor, and a formation factor calculation result more conforms to an actual formation condition for determining a more accurate oil saturation result.

Description

technical field

[0001] The invention relates to a well logging evaluation technology in petroleum exploration, in particular to a method for determining formation factors of low-permeability reservoirs and a method for determining oil saturation based on conductive fluid volume and conductive path, which are applied in well logging interpretation. Background technique

[0002] The main task of well logging interpretation is to identify and quantitatively evaluate oil and gas layers. The electrical properties of water-saturated rocks represented by Archie’s formula and its extended forms are the basis for quantitatively evaluating oil saturation using well logging data. In the development of quantitative interpretation of well logging played an important role in. The classic Archie's formula is suitable for pure sandstone with intergranular pores and good porosity and permeability. It has a relatively simple pore size distribution, good pore-throat matching relationship, and ...

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