METHOD OF SECONDARY DEVELOPMENT OF HIGH-VISCOSITY OIL DEPOSIT Russian patent published in 2002 - IPC

FIELD: secondary methods of recovery of high-viscosity oil, particularly, methods of heat stimulation of formations. SUBSTANCE: method includes well drilling from surface over contour of development district with location of bottoms of gently descending wells in region of bottoms of underground wells drilled during primary development of deposit by mine method from underground gallery; drilling of well into center of development district, alternation of steam injection into well with oil withdrawal from them. Method is distinguished from known ones by the fact that additional wells are drilled from surface round underground gallery at a distance from 10 to 100 m. During steam injection into wells drilled over contour and in center of developed block, oil is withdrawn from additional wells, and during oil withdrawal from wells drilled over contour and in center of developed block, displacement agent, for instance, water is periodically injected into additional wells. In case of steam break-through into additional wells, injected into them is an isolating composition and on deposit regions with low permeability of formation, horizontal wells are drilled. EFFECT: increased rate of oil withdrawal from deposit. 3 cl, 6 dwg