GB/T 39539-2020Technical requirements for determination of gas diffusion coefficient in shale reservoir (English PDF)

1 Scope

This standard specifies the method and technical requirements for the determination of gas diffusion coefficient of shale reservoirs:

This standard is applicable to the determination of gas diffusion coefficient in shale reservoirs:

The test range of gas diffusion coefficient of shale reservoirs in this standard: 1:0×10-3cm2/s~1:0×10-8cm2/s:

2 Normative references

The following documents are indispensable for the application of this document: For dated reference documents, only the dated version applies to this article

Pieces: For undated references, the latest version (including all amendments) applies to this document:

GB/T 19560-2008 High-pressure isothermal adsorption test method for coal

GB/T 29172-2012 core analysis method

3 Terms and definitions

The following terms and definitions apply to this document:

3:1

Shale reservoir gas diffusion coefficient gasdiffusioncoefficientinshalereservoir

A physical quantity representing the gas diffusion capacity in shale reservoirs, and the mass of gas passing through a unit area in a unit time:

Note: The unit is square centimeters per second (cm2/s):

3:2

Gas concentration

The mass of gas contained in a shale sample per unit volume:

Note: The unit is milligrams per cubic centimeter (mg/cm3):

4 Method summary

First, place the columnar shale sample in a dry state or a balanced water state in a core holder, and then saturate the core with gas:

After the pressure at both ends is balanced, open the outlet end to measure the core pressure, the gas volume produced, and the time, and then use the Fick diffusion theory to calculate the page

Diffusion coefficient of methane gas in rock reservoirs:

5 Equipment and materials

5:1 The equipment required for sample preparation includes:

---Drilling prototype;

---Drying box;

---Dryer;