Measurement method of pore size distribution characteristic of oil-bearing dense sandstone

Abstract

The invention provides a measurement method of the pore size distribution characteristic of oil-bearing dense sandstone, belongs to the field of geology, and particularly relates to the field of dense sandstone. Octamethyl cyclotetrasiloxane is taken as probe liquid, the nano-scaled pore of the oil-bearing dense sandstone can be completely and quantitatively depicted, and the characterization precision of the pore size distribution numerical value of the oil-bearing dense sandstone is improved. The measurement method comprises the following the following steps: performing pretreatment on an oil-bearing dense sandstone sample; testing an oil-bearing dense sandstone original sample through a nuclear magnetic resonance freezing-thawing method; testing a saturated sample through the nuclear magnetic resonance freezing-thawing method for oil-bearing dense sandstone original sample saturated octamethyl cyclotetrasiloxane; and computing the pore size distribution of the oil-bearing dense sandstone through data of the oil-bearing dense sandstone original sample and the oil-bearing dense sandstone saturated sample.

Description

technical field [0001] The invention relates to the field of geology, in particular to the field of tight sandstone, and in particular to a method for measuring the pore size distribution characteristics of oil-bearing tight sandstone. Background technique [0002] In recent years, with the continuous in-depth development of oil and gas exploration and development, the focus of oil and gas resources research at home and abroad has gradually shifted from shallow layers to deep layers, from conventional oil and gas reservoirs to unconventional oil and gas reservoirs, tight gas, shale gas, coalbed methane, tight oil, etc. Unconventional oil and gas have shown great potential under the current economic and technological conditions. China's conventional oil and gas resources are relatively poor, but unconventional oil and gas resources are abundant, especially tight oil and gas development and utilization potential is huge. Therefore, tight sandstone oil and gas are of great sign...

AI Technical Summary

Problems solved by technology

[0004] There are two relatively mature methods for measuring the pore size distribution characteristics of oil-bearing tight sandstone. The first method uses organic reagents to wash off the residual oil in tight sandstone, and then uses mercury porosimetry to measure. The problem with this method is that on the one hand The use of simple organic reagents cannot thoroughly clean the residual oil and gas in the semi-open pores and some open pores, so that when the mercury porosimetry is used for measurement, the test results will be too small; Excessive mercury injection pressure will change part of the pore structure, thus making the test results deviate from the true value

The second method is to use organic solvent to extract the residual oil in tight sandstone, and then use gas adsorption method to measure it. This method also has limitations similar to the first method. Unable to completely measure the nanopore size distribution of oil-bearing tight sandstone

Both of these methods have certain defects and application limitations, and both of them will lead to a smaller pore size content.

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