METHOD OF DEVELOPMENT OF OIL FIELD WITH NONUNIFORM RESERVOIRS AND DIFFICULTLY RECOVERABLE OIL RESERVES Russian patent published in 2003 - IPC

FIELD: oil producing industry. SUBSTANCE: method includes drilling of vertical wells with wide spacing pattern for finish study of nonuniformity of formation reservoir properties, oil recovery from drilled wells under conditions of flexible filtration regime. Low-permeability zones with difficulty recoverable oil reserves are revealed by data of geological field analysis and results of well operation. System of flooding is formed by water injection into low-permeability zones and displacement of oil from these zones to high-permeability zones. For this purpose, majority of injection wells for water injection are located in low-permeability zones by drilling horizontal injection wells with sidetracking of horizontal wellbores mainly from marginal vertical producing wells. Ratio of number of producing wells to number of injection wells is taken less than unity. Volumes of recovered oil, gas and water are compensated by water injection. EFFECT: reduced volumes of produced water, increased recovery factor of oil due to increased stimulation of low- drained and difficulty recoverable oil reserves in low-permeability reservoirs. 6 cl, 3 dwg, 1 ex