METHOD OF DEVELOPING METHANE-COAL WELL Russian patent published in 2012 - IPC E21B43/25 E21B43/12 

FIELD: oil-and-gas industry.

SUBSTANCE: invention relates to production of natural gas ad may be used in methane-coal well development. Proposed method comprises perforation of operation string in interval of production bed and its hydraulic fracturing. Thereafter, operation string is flushed. Settled fluid level allows defining initial counter pressure on productive coal bed. Production tubing with borehole pump is lowered into flow tubing, the pump being located under perforation interval. Well head is sealed. Borehole pump is used to reduce fluid level in well annuity space to below perforation interval together with injection of buffer gas therein at initial counter pressure on the bed. Thereafter, feed of buffer gas is interrupted. Said fluid level in annuity space is maintained by means of borehole pump. Inflow of bed fluid is caused by releasing excess pressure of buffer gas from annuity space in control over variation in gas quantitative and/or qualitative composition at well head. Change in released buffer gas composition allows defining the beginning of coal methane from productive bed. Now, rate of buffer gas pressure release is decreased.

EFFECT: higher efficiency of well development.

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