METHOD OF TREATMENT OF PRODUCTION CARBONATE RESERVOIR Russian patent published in 2015 - IPC E21B43/27 E21B43/22 

FIELD: oil and gas industry.

SUBSTANCE: method of treatment of production carbonate reservoir includes separation of the treatment intervals oil saturated rocks of the carbonate reservoir opened by the well with open horizontal hole, run to the reservoir treatment interval of the pipes string with ejector with nozzles having holes located radially at angle 120° to the generatix, acid injection to the reservoir treatment intervals through tubings under jet effect, alternating the acid doses with doses of sand-water solution of the surface-active substance, used for jet sand action on the reservoir treatment intervals. After separation of the treatment intervals in the oil saturated rocks of the carbonate reservoir opened by the well with open horizontal hole at the wellhead the pipes string is equipped from bottom to top: spherical funnel, ejector nozzle with seat for outwashed lock element dropped in the pipes string from the wellhead, centring branch, at the opened casing valve at the wellhead the pipes casing with washing by the process liquid and rotation is run in the well, the ejector nozzle is installed against beginning of the treatment interval nearest to the bottomhole of the open horizontal hole, from the wellhead the outwashed lock element is dropped in the pipes string, and by the process liquid it is moved to the seat of the ejector nozzle, then the string is rotated from the wellhead, and acid dose is injected via the string under mode of the acid jetting with creation of the transverse plane, then string rotation from the wellhead and acid injection via the string are stopped, and the string is moved from the bottomhole to the wellhead by 1 m within the treatment interval, and under mode of the acid jetting the next transverse plane is made above as described above, then the process with creation of the transverse planes is repeated after each 1 meter depending on the length of the treatment interval in the well open horizontal hole from the string rotation from the wellhead to string movement from the bottomhole to the wellhead by 1 m within the treatment interval of the well open horizontal hole, upon completion of creation of the last transverse cavity within the treatment interval of the well open horizontal hole, the casing valve at the wellhead is closed without stop of the casing rotation from the wellhead, via the pipes casing the sand-water solution of SAS is injected under mode of sand jetting of the transverse plane, string rotation from the wellhead and sand-water solution of SAS injection via the casing are stopped, then string in moved from the wellhead to the bottom hole by 1 m, and under sand jetting the next transverse plane is treated as described above, then the process is repeated depending on number of the transverse cavities in the treatment interval from the string rotation from the wellhead and to string movement from the wellhead to the bottomhole by 1 m within the treatment interval of the well open horizontal hole; similarly the acid jetting and sand-water solution SAS jetting are performed in relation to all rest treatment intervals of the well open horizontal hole, the lock element and residues of sand mixture are washed out the well open horizontal hole by the process liquid injection in annulus with simultaneous rotation and movement of the string in the well open horizontal hole from the wellhead to the bottomhole, at that prior to the string build-up the well open horizontal hole is washed by one cycle with three times reaming to the length of one pipe until the ball funnel will reach the bottomhole of the well open horizontal hole, then the string is lifted to the surface.

EFFECT: increased efficiency of acid treatment of the carbonate reservoir intervals opened by the well open horizontal hole, increased oil recovery of the carbonate reservoir, exclusion of the probability of the emergency in well linked with sticking of the string, reduced duration of the reservoir treatment.

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