We studied the microscopic pore structure of the organic-rich Longmaxi Formation shale in Sichuan Basin through Argon Ion milling-Field Emission Scanning Electron Microscopy characterization with different SEM parameters

and investigated the effect of electron microscopic parameter variation on the quantitative evaluation of the microscopic pores of shale based on the pore data extracted by the "optimal threshold method" within the same field of view.The results show that the probe current and accelerating voltage among these electron microscopic parameters

have greater influence on the accuracy of quantitative pore data extraction.When the beam exceeds 170PA

the higher the voltage is adjusted to

the smaller the large pore area is extracted.When the voltage exceeds 15KV

the beam current is lower

and the pores extracted are relatively more complete; while as the beam current is lower than 86PA

the longer the scanning time is

the more completely the pore is extracted

but as it exceeds 86PA

the scanning time has little effect on pore extraction.In addition

luminance and contrast values of excessive lowness or highness are detrimental to pore extraction

and the pore extraction comes to the most complete when their values are 47.5 and 85 respectively.In conclusion

the parameters of electron microscopy have a remarkable influence on the extraction of organic pores

and the proper selection of parameters can significantly improve the accuracy of quantitative data extraction for shale micropores

in a bid to obtain more realistic data of shale micropore structure.