METHOD FOR ABANDONING A WELL Russian patent published in 1997 - IPC

FIELD: oil and gas well drilling and abandoning. SUBSTANCE: cement bridge is installed in casing string over the productive horizon. Then in-casing space gets open to its casing string borehole annulus within the range of high ductile rocks with standby borehole available. Then additional cement bridge is installed so as its roof be adequate to lower boundary of the interval of the highly ductile rocks. Then flowing of the highly ductile rocks to the in-case space by installing hydrostatic pressure (P, MPa) on condition that: , where ρ_av. is mean weighted density of rocks, gram per cubic centimeter; H is the depth of interval foot of the highly ductile rocks; ρ_f is equivalent yield strength of the highly ductile rock, MPa. EFFECT: higher reliability in abandoning wells.