Method for establishing tight sandstone reservoir permeability calculation model

Abstract

The invention relates to a method for establishing a tight sandstone reservoir permeability calculation model, which comprises the following steps: extracting pores by using a laser scanning confocal microscope based on the laser scanning confocal microscope and image processing; secondly, extracting a surface porosity, a pore shape factor, an equivalent pore diameter, a pore diameter sorting index and fractal dimension parameters by utilizing image processing to represent a pore structure, and further establishing a permeability calculation model through the pore structure parameters. According to the invention, the permeability calculation model established by the method is used for predicting the permeability of the tight sandstone reservoir, the permeability can be accurately predicted, the permeability prediction of any position of the sample can be completed, the defect that the permeability of the tight sandstone reservoir is evaluated only depending on a rock columnar sample or logging data in the past is overcome, the reservoir permeability evaluation can better reflect the heterogeneity of the reservoir, the evaluation result is more comprehensive, and the exploration and development success rate is effectively improved.

Description

technical field [0001] The invention belongs to the technical field of oil and gas geological exploration, and in particular relates to a method for establishing a calculation model of tight sandstone reservoir permeability. Background technique [0002] For tight sandstone reservoirs, the overburden matrix permeability is ≤0.1×10 -3 μm 2 (equivalent to air permeability ≤ 1 × 10 -3 μm 2 ), reservoirs with porosity less than 10% (Zou Cai et al., 2013). Different from conventional reservoirs, tight sandstone reservoirs are characterized by small pore size, poor porosity and permeability, complex pore structure, and strong heterogeneity (Zhu Rukai et al., 2016). The pore structure determines the porosity and permeability of the reservoir. Permeability, and affect its reservoir performance and seepage capacity (Wang Guoting et al., 2013). At present, pore structure characterization technology is committed to improving the dimension and resolution of characterization (Wu Son...

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Problems solved by technology

[0004] The present invention aims at the above-mentioned problems existing in the prior art, such as the inability to reflect the difference in permeability heterogeneity inside rock samples, etc., and provides a method for establishing a permeability calculation model of tight sandstone reservoirs. The permeability calculation model established by this method, It can accurately calculate the permeability of any position of the sample, solve the shortage of evaluating the permeability of tight sandstone reservoirs by relying solely on rock columnar samples or logging data in the past, and make the evaluation of reservoir permeability more reflect the heterogeneity of reservoirs

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