METHOD FOR DEVELOPMENT OF CARBONATE RESERVOIR WITH HORIZONTAL WELLS Russian patent published in 2016 - IPC E21B43/27 

FIELD: oil and gas industry.

SUBSTANCE: method for development of carbonate reservoir with horizontal wells involves drilling of horizontal wells, lowering pumps on pipe string to horizontal part of holes, acid treatment of reservoir through filters with different density of perforation, withdrawal of well production. At that, into horizontal hole, which is made open, two pipe strings of 1.5-2 inch diameter are lowered, wherein central borehole pump is installed into one of them, and serially connected filters are installed in another along whole length of string; perforation density N_n of each n-th filter section is performed according to ratio: N_n = N_min·k_max/k_n, where k_max - maximum reservoir permeability along horizontal hole, k_n - permeability of n-th collector section, N_min - density of perforation holes in filter section opposite reservoir with maximum permeability. Into annular space, up to mouth, service water is pumped, hereafter acid is supplied into pipe string with filters, the flushed by process water in volume not less than volume of pipe string, through which acid was injected. After reaction of acid with rock, via same string, reaction products are extracted until oil appears, then pump is set into operation in horizontal shaft. If oil flow rate drops by more than 50 % of oil flow rate after acid treatment, process of acid treatment is repeated, wherein volume of service water for pressing of acid is selected at least 2 volumes of service water compared to used in previous treatment cycle.

EFFECT: increasing oil recovery of inhomogeneous carbonate reservoir.

1 cl, 1 dwg