Three-dimensional imaging method of shale nanopores by focused ion beam-helium ion microscope

Abstract

The invention mainly belongs to the field of oil and gas exploration and development, and particularly relates to a three-dimensional imaging method of shale nanopores with a focused ion beam-helium ion microscope. The method adopts the ultra-high resolution imaging function of a helium ion microscope and the cutting function of the focused ion beam to perform ultra-high resolution three-dimensional imaging of the nanopores of the shale organic matter, which has the characteristics of high resolution, thin slice, and uniform and stable slice. The method makes up for the disadvantage of the technology combined traditional scanning electron microscope with focused ion beam that cannot perform three-dimensional imaging for nanopores. The method can visually show the characteristics of pores over 3nm in shale organic matter such as three-dimensional spatial structure, morphology, distribution, connectivity and porosity, which has great significance for scientifically explaining the mechanism of shale gas occurrence and migration.

Description

technical field [0001] The invention relates to the field of three-dimensional structure imaging of shale, in particular to a method for three-dimensional imaging of shale nanopores by a focused ion beam-helium ion microscope. Background technique [0002] In recent years, shale gas, as a kind of unconventional natural gas, has attracted widespread attention in the industry. The large-scale development of shale gas is conducive to balancing my country's energy structure, reducing environmental burdens, and ensuring national energy security. Pores in shale are an important research object in the exploration and development of shale gas. According to their development location, they can be divided into two categories: inorganic pores and organic pores. The successful development cases of shale gas in China and the United States show that shale gas is mainly stored in nanopores by adsorption, and nanopores in organic matter are the main source of shale nanopores, and organic ma...

AI Technical Summary

Problems solved by technology

Therefore, it is difficult for FIB-SEM technology to perform three-dimensional imaging of nanoscale mesopores and small pores.

A variety of experimental test results show that in high-yield shale gas blocks, mesopores and small pores below 50 nm are generally developed in shale organic matter, but there are few reports on the technology that can realize ultra-high resolution three-dimensional imaging of them

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