Method for determining effective rock stress coefficient based on pore compression experiment

A technology of pore compressibility and effective stress, which is used in the application of stable tension/pressure to test the strength of materials, analysis of suspensions and porous materials, and measurement devices. The effect of simple test equipment, convenient technical solutions, and concise test methods

Active Publication Date: 2014-10-08
CHINA UNIV OF PETROLEUM (BEIJING)
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

This method can be combined with the existing experimental equipment in the field of seepage mechanics, overcome the shortcomings of the current effective stress coefficient experimental calculation method, which is cumbersome, complex, and large in error, and realize the rapid and accurate measurement of the effective stress coefficient of the reservoir

Method used

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  • Method for determining effective rock stress coefficient based on pore compression experiment
  • Method for determining effective rock stress coefficient based on pore compression experiment
  • Method for determining effective rock stress coefficient based on pore compression experiment

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0055] like figure 1 As shown, a method for determining the effective stress coefficient of rock based on pore compression experiments includes the following steps in sequence:

[0056] (1) Select a low-permeability sandstone reservoir porous medium rock, select two cores with similar physical properties in the same direction of the rock, and test the basic physical parameters of the cores, as shown in Table 1.

[0057] Table 1: Basic physical parameters of the core

[0058] Core number

Length (cm)

diameter (cm)

Permeability (mD)

Gas porosity (%)

YWT-B1

6.138

3.775

0.1252

12.471

YWT-B2

6.162

3.772

0.1272

12.378

[0059] (2) Vacuum the core YWT-B1 and core YWT-B2, and then immerse them in standard brine to saturate the fluid. While maintaining the pore pressure at the room pressure, gradually increase the triaxial confining pressure on the core YWT-B1 to measure the pressurization The volume of stan...

Embodiment 2

[0085] like figure 1 As shown, a method for determining the effective stress coefficient of rock based on pore compression experiments includes the following steps in sequence:

[0086] (1) Select a low-permeability sandstone reservoir porous medium rock, select four cores with similar physical properties in the same direction of the rock, and test the basic physical parameters of the cores, as shown in Table 3.

[0087] Table 3: The basic physical parameters of the core

[0088] Core number

Length (cm)

diameter (cm)

Permeability (mD)

Gas porosity (%)

YWT-B1

6.138

3.775

0.1252

12.471

YWT-B2

6.176

3.772

0.1797

11.347

YWT-B3

6.180

3.770

0.1133

12.257

YWT-B4

6.162

3.772

0.1272

12.378

[0089] (2) Vacuumize the four rock cores in step (1), and then immerse them in standard brine to saturate the fluid. Under the condition that the pore pressure is maintained ...

Embodiment 3

[0103] like figure 1 As shown, a method for determining the effective stress coefficient of rock based on pore compression experiments includes the following steps in sequence:

[0104] (1) Select a low-permeability sandstone reservoir porous medium rock, select four cores with similar physical properties in the same direction of the rock, and test the basic physical parameters of the cores, as shown in Table 5.

[0105] Table 5: The basic physical parameters of the core

[0106] Core number

Length (cm)

diameter (cm)

Permeability (mD)

Gas porosity (%)

YWT-B1

6.138

3.775

0.1252

12.471

YWT-B2

6.176

3.772

0.1797

11.347

YWT-B3

6.180

3.770

0.1133

12.257

YWT-B4

6.162

3.772

0.1272

12.378

[0107] (2) Vacuumize the four rock cores in step (1), and then immerse them in standard brine to saturate the fluid. Under the condition that the pore pressure is maintained ...

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Abstract

The invention discloses a method for determining an effective rock stress coefficient based on a pore compression experiment. The method comprises the following steps: selecting cores with similar physical properties in the same direction of the same rock, vacuumizing saturated fluid, gradually increasing triaxial confining pressure under the condition that the pore pressure is maintained to be room pressure, measuring the volume of fluid discharged from pores in the pressurization process, determining the rock pore compression coefficient, fitting a fitting function between the effective stress and the pore compression coefficient, measuring a pore pressure constant value of the saturated core and the pore pressure value after the confining pressure is increased, determining core pore volume reduction, and finally determining the effective rock stress coefficient value according to a calculation formula of the effective stress born by a rock matrix and the rock pore compression coefficient. The method is applied to low-permeability and ultralow-permeability reservoir stress research, the testing equipment is simple, the principle is clear, and the method is simple and accurate in measurement result.

Description

technical field [0001] The invention belongs to the technical field of oil field drilling, and relates to a method for determining rock mechanical coefficients, in particular to a method for determining rock effective stress coefficients based on pore compression experiments. Background technique [0002] In various engineering design, construction, mining, oil drilling and other fields, the determination of rock mechanics parameters is an important basis for formulating drilling, well completion, oil and gas development and construction measures. Especially in the field of oil drilling, it is more important to determine the effective stress coefficient of porous medium rock in sandstone reservoirs, which directly affects the reasonable prediction of the effective stress borne by the porous medium rock skeleton. The reasonable determination of rock mechanics parameters will ultimately affect the design of the overall oilfield scheme, and then affect the production volume of ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): G01N3/12G01N15/08
Inventor 申颍浩葛洪魁栾国华王小琼杨柳李曹雄任凯陈浩
Owner CHINA UNIV OF PETROLEUM (BEIJING)
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