Construction method of dense sandstone multi-scale pore model and application

Abstract

The invention relates to the field of research on the physical properties of sandstone of low-permeability dense sandstone reservoir, and discloses a construction method of a dense sandstone multi-scale pore model and an application. The invention provides the construction method of a dense sandstone multi-scale pore model, which comprises the following steps: (1) developing a mercury injection experiment and establishing a rock sample capillary pressure curve; (2) establishing a three-dimensional digital core by using Micro-CT scanning; (3) determining the spatial position coordinates and geometric construction characteristic parameters of the pore and simplifying the pore into pore nodes; (4) determining the communication relation among the pore nodes according to the spatial position ofthe pore nodes; (5) distributing pore throat radius, establishing an initial pore model, and then fitting the initial pore model into a capillary pressure curve; and (6) adjusting pore throat parameters and pore parameters in the initial pore model according to the actually measured capillary pressure curve. The pore model disclosed by the invention is accurate and reliable.

Description

technical field [0001] The invention relates to the field of research on petrophysical properties of low-permeability tight sandstone reservoirs, in particular to a construction method and application of a multi-scale pore model of tight sandstone. Background technique [0002] Low-permeability tight sandstone is an important oil and gas reservoir, containing rich oil and gas resources, and is one of the key areas of exploration and development at present. In order to efficiently develop the oil and gas in the pore space of low-permeability tight sandstone, it is first necessary to have an accurate understanding of the pore structure and physical parameters of the reservoir rock, which is the basis and key of reservoir evaluation and oil and gas development. [0003] For medium-high permeability sandstone, currently the core experiment analysis method is mainly used to analyze the physical properties and seepage characteristics of various reservoir rocks. This type of metho...

AI Technical Summary

Problems solved by technology

However, because the existing Micro-CT scanning system can only obtain micron-resolution images, it cannot identify the nanopore throats commonly developed in low-permeability tight sandstones, so it is not suitable for such rocks

Although more advanced Nano-CT systems can be used to obtain pore images with nanoscale resolution, the field of view of CT images is generally inversely proportional to the resolution, that is, the higher the resolution, the smaller the size of the captured image. Therefore, Nano-CT system cannot meet the image size requirements of multi-scale pore modeling

In addition, high cost, time-consuming, and scarcity of instruments also limit the widespread use of Nano-CT systems

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