Coalbed gas well quantitative drainage experimental device and drainage control method

Abstract

The invention discloses a coalbed gas well quantitative drainage experimental device and a drainage control method. The device includes: a monitoring system, a drainage simulation system and a supply recovery system. The drainage simulation system includes: a core holding cabin and a pressurized cabin , incubator, vacuum pump, booster pump; the supply and recovery system includes: helium gas cylinder, methane gas cylinder, water supply tank, helium gas recovery gas cylinder, methane recovery gas cylinder, return water tank, helium gas supply pressure regulating valve, methane supply Air pressure regulating valve, water supply pressure regulating valve, return water pressure regulating valve, helium gas recovery pressure regulating valve, methane recovery pressure regulating valve, pressurized water pump; monitoring system includes: controller, and gas supply electrically connected with the controller Pressure sensor, water supply pressure sensor, outlet pressure sensor, methane recovery pressure sensor, gas supply flowmeter, water supply flowmeter, helium gas recovery flowmeter, methane recovery flowmeter, return tank liquid level indicator. The invention can fulfill the requirements of simulation and monitoring of coal bed gas exhaustion.

Description

technical field [0001] The invention relates to the technical drainage field of coalbed gas wells, in particular to an experimental device for quantitative drainage of coalbed gas wells and a drainage control method. Background technique [0002] The statements in this section only provide background information related to the present disclosure and may not constitute prior art. [0003] my country is rich in coalbed methane resources and has broad development potential. However, my country's coalbed methane reservoirs have complex geology, have experienced many tectonic movements, have natural difficulties of low pressure and low permeability, and are sensitive to stress, and the output of pulverized coal is sensitive to damage. challenge. [0004] On the one hand, the coalbed methane drainage technology must reduce the bottom hole flow pressure as soon as possible to obtain sufficient production pressure difference; on the other hand, it must ensure relatively slow mining...

AI Technical Summary

Problems solved by technology

However, this method cannot restore the mechanical state of the formation by unilateral pressurization, and the water injection process cannot restore the original gas-water distribution state of the coal reservoir.

Simple simulation and drainage and depressurization cannot test the porosity and permeability of actual coal samples, nor can it realize quantitative control of back pressure to simulate actual bottomhole flow pressure changes and monitor coal sample permeability changes

Therefore, this method still cannot meet the requirements of coalbed methane drainage simulation and monitoring.

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