Method for quantitatively characterizing wettability of shale by using small-angle neutron scattering

Abstract

The invention provides a method for quantitatively characterizing wettability of shale by using small-angle neutron scattering. The method comprises the following steps: S1, preparing a shale sample to be detected; S2, performing a small-angle neutron scattering experiment on the shale samples to be detected to obtain a first shale pore volume and pore diameter distribution diagram of each shale sample to be detected; S3, preparing a mixed solution; S4, putting a shale sample to be detected into the mixed solution for infiltration; and S5, performing a small-angle neutron scattering experiment on each shale sample to be detected to obtain a secondary pore volume and pore diameter distribution diagram of each shale sample to be detected, comparing and analyzing a result in each first shale pore volume and pore size distribution diagram and a result in each second pore volume and pore size distribution diagram, and quantitatively characterizing the shale wettability of each shale sample to be detected. According to the method, the wettability of the shale micro-pores can be quantitatively represented more accurately, and the error is small.

Description

technical field [0001] The present application relates to the field of unconventional natural gas, in particular to a method for quantitatively characterizing shale wettability by using small-angle neutron scattering. Background technique [0002] The wettability of shale is one of the important parameters to characterize the physical properties of rocks, and has an important impact on the distribution of oil and gas in the shale pore space, remaining oil saturation, capillary force, relative permeability and water flooding effect during production. . Therefore, accurately judging the wettability of reservoirs in the process of shale oil and gas production has indicative significance for optimizing production, fracturing fluid flowback, water-rock interaction, and selection of fracturing fluid and additives. [0003] At present, the methods for studying wettability include quantitative and qualitative methods. Quantitative analysis methods include contact angle method, drip...

AI Technical Summary

Problems solved by technology

[0004] One of the purposes of this application is to provide a method for quantitatively characterizing the wettability of shale by using small-angle neutron scattering, aiming to improve the problem of low accuracy of the existing wettability test of shale

Images