METHOD FOR DETERMINING INTERVAL OF FREE GAS FLOW FROM RESERVOIR IN OPERATING HORIZONTAL WELL Russian patent published in 2015 - IPC E21B47/10 

FIELD: oil and gas industry.

SUBSTANCE: method includes completion of the horizontal hole with registering instruments, simultaneous registration of temperature and pressure at several points of the horizontal well at pressure change in the well, subsequent comparison of temperature change in regard to pressure change at each registered point. At that temperature and pressure are registered at idle well when the well is input into operation at slow pressure decrease within period of time above oil saturation pressure with gas and at further pressure decrease within period of time below oil saturation pressure with gas; pressure change in the well is carried out by its slow decrease within period of time in regard to level of oil saturation pressure with gas, inflow of free gas from the reservoir within interval of the horizontal hole is defined on the basis of ratio of temperature change to pressure change in each registered point, at that on condition of sign stability for the ratio at pressure above and below the value of oil saturation pressure with gas. Inflow of free gas from the reservoir in comparison with degassing state is estimated against sign of the ratio in regard to oil saturation pressure with gas, which is conventionally zero level. Usage of this method allows unambiguous detection of interval of free gas inflow.

EFFECT: increased survey reliability for operating horizontal holes in order to detect intervals of free gas inflow to the operating well.

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