METHOD OF ABANDONMENT OF WELL WITH SOURCE OF ANNULAR SPACE PRESSURE Russian patent published in 2001 - IPC

FIELD: oil and gas producing industry. SUBSTANCE: selected above producing horizon is highly plastic rock bed located above source of annular space pressure and nearest to it, and the first cement bridging plug is installed in casing string. Upper boundary of the first cement bridging plug is installed at level of foot of selected highly plastic rock bed. Then, casing- wellbore annular space is communicated with casing space in interval comprising a part of thickness of highly plastic rocks directly above bed foot by removal a part of casing string. After this, installed above the first cement bridging plug is the second cement bridging plug with height equaling the interval of communication of casing- wellbore space with casing string space and extending beyond limits of casing string contour. Then, casing-well bore space is communicated with, on remaining part of thickness of highly plastic rock bed, with casing string space by removal of part of casing string, and flow of highly plastic rocks into casing space is ensured due to reduction of well hydrostatic pressure at level of interval of highly plastic rocks. EFFECT: higher reliability of well abandonment.