Shale pore quantitative expression method based on three-dimensional FIB-SEM image

Abstract

The invention relates to the field of petroleum and gas geologic exploration and development, especially a method for recognizing the type of internal three-dimensional pores in shale and the quantitatively expressing the structure information of the internal three-dimensional pores in shale petroleum and gas exploration through FIB-SEM. The method comprises the steps: carrying out the high-precision three-dimensional imaging of inorganic substances, organic substances and pores in the shale at micrometer and nanometer scales through the FIB-SEM, and obtaining a three-dimensional FIB-SEM image; carrying out the alignment of all two-dimensional images of the three-dimensional FIB-SEM image, correcting the nonuniformity of the image brightness, and filtering the noise of the image; segmenting the preprocessed image into a pore region, an organic substance and an inorganic substance; marking all pores the pore region of the image, and dividing the pores into an organic pore, an inorganic pore and a boundary pore according to the distribution conditions of the organic and inorganic substances around the pores; analyzing all pores through a mathematic method, and obtaining the expression parameters of the three-dimensional pores.

Description

technical field [0001] The invention relates to the field of geological exploration and development of petroleum and natural gas, in particular to a method of using FIB-SEM (focused ion beam-scanning electron microscope) to identify the type of three-dimensional pores inside shale and quantitatively characterize its structural information in shale oil and gas exploration. Background technique [0002] The oil and gas storage capacity of shale is closely related to factors such as porosity and effective porosity in shale, and the quantitative description of pore type and size directly determines the occurrence state, migration mechanism and ability. At the same time, during the depositional evolution of shale, the evolution of pores has always been one of the focuses of attention, and it is the focus of our research on the evolution history of shale oil and gas deposition. Therefore, it is of great significance to study and characterize the pores of shale reservoirs. [000...

AI Technical Summary

Problems solved by technology

Although this method of simulating three-dimensional space through two-dimensional data requires less machine time, it cannot truly reflect the distribution of organic and inorganic pores in three-dimensional space, and thus is of great importance for evaluating shale oil and gas storage capacity and the pores in pores. Occurrence state, migration mechanism and ability of oil and gas bring limitations

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