METHOD FOR DETECTION OF WELLS WATERED WITH BEHIND-CASING FLOWS OF WATER Russian patent published in 2016 - IPC E21B47/10 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil and gas industry, particularly to methods of searching for wells with behind casing leak. Method involves measurement of liquid extraction, its water flooding and oil extraction, calculation of excessive water cut and detection of wells producing excess water. Excessive water cut is calculated as difference between actual water cut and accepted water cut determined from water saturation of formation using a Backley-Leverette function. Wells are searched using graphic correlation of current values of actual water cutting of well production and current values water saturation of formation in its opening interval. Invention uses calculated curve of dependence of acceptable product water cut in oil water displacement from formation on its current water saturation, wherein current formation water saturation in opening intervals of each well is calculated in mathematical or in hydrodynamic model of deposit. Problematic wells with behind casing leak are recognised as wells located on graphic correlation above curve of acceptable water cut.

EFFECT: technical result of present invention is more effective method for detection of wells flooded with behind-casing flows of water, due to increased reliability of well survey by increasing duration of analysed initial period of their operation and due to considerable reduction of time spent on analysis.

3 cl, 1 dwg, 1 ex