Indoor experimental simulation method for testing injection pressure drop of coal bed gas

A technology of experimental simulation and coalbed methane, applied in the direction of earthwork drilling, wellbore/well components, etc., can solve problems such as high cost, lack of strict demonstration and exact data description, and achieve the effect of optimizing test parameters

Inactive Publication Date: 2012-05-30
PETROCHINA CO LTD +2
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] In the process of realizing the present invention, the inventor found that the prior art has at least the following problems: Since the basic principle of the injection pressure drop test is based on the test theory of conventional oil and gas reservoirs, whether it is applicable to unconventional natural gas such as coalbed methane, and how accurate it should be Selection of injection time and pressure drop time, whether injection pressure drop test can continue to be used in the development stage, etc. At present, these issues have not been strictly demonstrated and definite data explanation
These issues would be costly to conduct actual tests in the field

Method used

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  • Indoor experimental simulation method for testing injection pressure drop of coal bed gas
  • Indoor experimental simulation method for testing injection pressure drop of coal bed gas
  • Indoor experimental simulation method for testing injection pressure drop of coal bed gas

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Embodiment 1

[0023] refer to figure 1 with figure 2 , this embodiment provides an indoor experimental simulation method for the pressure drop test of coalbed methane injection, the simulation device for the pressure drop test of coalbed methane injection used in the method includes: a coalbed simulation device, an injection system, a pressure sensor and a data acquisition system.

[0024] The coal seam simulation device is used to simulate the coal seam in the area to be tested. The coal seam simulation device includes a casing 1, and a rubber elastic body 3 is arranged on the side of the inner wall of the casing 1 to simulate the elasticity of the coal seam. In the space surrounded by the casing 1 A plurality of hollow rubber balls 2 are provided, and the air in the hollow rubber balls 2 is used to simulate gas compressibility, and coal seams with different permeability are simulated by changing the size of the filled hollow rubber balls 2, and a gap is left on the upper surface of the s...

Embodiment 2

[0037] Simulating medium and high permeability coal seams: the permeability of the coal seam to be simulated is about 10mD, and the elastic modulus of the coal seam is about 1000MPa, which is a medium and high permeability coal seam. The rubber elastic body 3 which is equivalent to the elasticity of the coal seam is arranged close to the inner side wall of the casing 1, and the space formed by the rubber elastic body 3 casing 1 and the rubber elastic body 3 is filled with a hollow rubber ball 2 with a radius of 2 mm to form a medium-high Permeability simulated coal seams.

[0038] Injection stage: control the flow tester 7 to inject water into the injection wellbore 4 at a rate of 1ml / min for 5 minutes;

[0039] Pressure drop stage: stop the injection after 5 minutes of water injection, and end the simulation test after 10 minutes.

[0040] In the injection stage and the pressure drop stage, the pressure sensor 9 is used to monitor the pressure change with time in the injecti...

Embodiment 3

[0044] Simulating medium and high permeability coal seams: the permeability of the coal seam to be simulated is about 10mD, and the elastic modulus of the coal seam is about 1000MPa, which is a medium and high permeability coal seam. The rubber elastic body 3 which is equivalent to the elasticity of the coal seam is arranged close to the inner side wall of the casing 1, and the space formed by the rubber elastic body 3 casing 1 and the rubber elastic body 3 is filled with a hollow rubber ball 2 with a radius of 2 mm to form a medium-high Permeability simulated coal seams.

[0045] Injection stage: control the flow tester 7 to inject water into the injection wellbore 4 for 2.5 minutes at a rate of 2ml / min;

[0046] Pressure drop stage: stop the injection after 2.5 minutes of water injection, and end the simulation test after 5 minutes.

[0047] In the injection stage and the pressure drop stage, the pressure sensor 9 is used to monitor the pressure change with time in the inje...

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Abstract

The invention discloses an indoor experimental simulation method for testing the injection pressure drop of coal bed gas, and belongs to the technical field of oil and gas production engineering. The method comprises the following steps: selecting a rubber elastic body according to the elastic modulus of a coal bed in a region to be simulated, selecting a hollow rubber ball according to the seepage rate of a coal bed to be simulated, and assembling a coal bed simulating device; setting the water injection rate and the water injection time of an injecting system, and injecting water to the coal bed simulating device through the injecting system; stopping injecting after the water injection time is finished; and testing and collecting pressure values at an injection stage and a pressure drop stage. The indoor experimental simulation method for testing the injection pressure drop of the coal bed gas is used for inspecting whether a method for testing the injection pressure drop is applicative or not for the coal beds with different seepage rates at different stages of developing the coal bed gas.

Description

technical field [0001] The invention relates to the technical field of oil and gas production engineering, in particular to an indoor simulation method for testing pressure drop of coal bed gas injection. Background technique [0002] Coalbed methane is an efficient and clean unconventional natural gas resource. At present, coalbed methane resources are actively developed at home and abroad to alleviate the energy crisis, and at the same time realize sustainable energy development on the premise of protecting the environment. Large-scale commercial development of coalbed methane in my country is imminent. [0003] Reasonable and efficient development of coalbed methane resources must rely on the dynamic monitoring of coalbed methane, and coalbed methane well testing technology is the main source of dynamic data for the formulation and adjustment of coalbed methane reservoir development plans, and can be called the "eyes" of coalbed methane reservoir engineers . Injection p...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): E21B49/00
Inventor 赵培华刘曰武张均峰苏中良欧阳伟平
Owner PETROCHINA CO LTD
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