METHOD OF WELL INVESTIGATION Russian patent published in 2010 - IPC E21B47/10 G01V5/04 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to oil and gas industry and can be used during operation of well. Well is outfitted by flow column (FC) with swage at bottom end. String opening of flow column is located higher than upper boundary of perforation interval for 10-30 m. Before implementation of investigations it is implemented operation of well with working substance pumping used during development of oil pool by column of flow column during 3 and more days. Well is stopped. It is implemented technological isolation during 1-2 days. It is implemented thermometry (TM) and gamma-ray logging of well by column of FC with recording of background value of natural radioactivity of rocks and background distribution of temperature by borehole. It is pumped the first disturbing water volume into bed through the string of CF or hole annulus. During pumping of disturbing water volume there are repeatedly replaced devices from well bottom up to interval, located 40-60 m higher than string shoe of FC, at different speed ranges and there are fixed registration of flow-measuring apparatus. Pumping is stopped and it is implemented iterative TM of well from well bottom up to collar with recording of current temperature distribution by the borehole. After iterative TM it is resumed pumping of water and during the water pumping process there are lifted devices up to well collar with registration of thermometre and flow-measuring apparatus. It is pumped the second disturbing volume and it is implemented recording of thermogram of pumping by all borehole after 5-10 minutes after stop. After pumping of the second disturbing water volume and TM there are descended devices into the interval of productive stratum (PS), it is pumped the third distributing water volume with simultaneous implementation as minimum of one measurement of TM in the range of PS and after stop of pumping of the third distributing volume it is implemented TM with removal of at least two thermograms in the range of PS from the bottom and for 50 m higher than PS for identification of behind-the-casing circulation. There are analysed received data. After analysis of received information it is implemented specification of temperature measurements at section of well string with ascertained temperature anomalies. In ascertained intervals there are implemented additional investigations for confirmation or confutation of presence of TA, for specification of ranges of TA. For identification of ranges of borehole in which it is horizontal movement of underground water it is additionally pumped disturbing water volume, it is stopped pumping and it is implemented NV in the range from the well collar up to the range overlapping area of active movement of underground water, after 5-10 min, after 30 min, after 60 min and after 3 hours after pumping stop. In case if presence of TA investigations are stopped. At absence of TA it is continued implementation of TA up to achieving of water temperature in the borehole, equal to temperature of environmental rocks.

EFFECT: increasing of authenticity of detection of discontinuity of well production string, definition of casing cross-flow and horizontal movements of water in behind-the-casing space.

5 cl, 2 dwg