CONTROL OVER VARIATION OF GAS WELL BOTTOM ZONE SEEPAGE RESISTANCE FACTORS Russian patent published in 2014 - IPC E21B47/00 

FIELD: oil-and-gas industry.

SUBSTANCE: invention relates to oil industry and may be used in development of gas deposits. Proposed method comprises recording of gas flow rate and wellhead pressure between the dates of gas-dynamic analysis of settled samplings and determination of first and second main components corresponding to the largest proper number of covariance matrix of initial data. The latter comprises zero and first derivatives of gas yield, squared gas yield, analysis of first and second main components in time. Graphs of their variation is time are plotted to make the conclusion about well operation mode changeovers at intersection of curves of said first and second main components. In compliance with this invention, water samples are taken to define the content of chloride-ion along with recording of gas flow rate and bottomhole pressure. In case chloride ion content corresponds to its content in condensation water precipitated due to changed thermodynamic conditions of gas flow, conclusion is made that mode change testifies to seepage resistance change owing to rock strain change.

EFFECT: allowance for gas bearing bed strained state change influence on change of working area filtration factors.