METHOD FOR DEVELOPMENT OF HYDROCARBON POOL Russian patent published in 1995 - IPC

FIELD: development of hydrocarbon pools. SUBSTANCE: method for development of hydrocarbon pool includes pool development by drilling producing and injection wells located in gas and water-saturated zones, injection of water through injection wells and withdrawal of hydrocarbons through producing wells. Development operations are carried out with constant increase of formation pressure and redissolving of gas liberated from oil in oil. Formation pressure is increased to value which is established from relation P_form≥ P_act+σ_gas/1-σ_wat·P_act/P_atm·T_stand/T_form·Z(P_atm)/Z(P_act), 1/C, where P_form, P_act, P_atm are: pressure at which gas dissolves fully in oil, MPa; actual formation pressure, MPa; atmospheric pressure, MPa; σ_gas,σ_wat are initial gas and water saturation values in oil; T_stand,T_form are standard and formation temperature, K; Z(P_atm)·Z(P_act) are coefficients of overcompression of formation gas at atmospheric and actual formation pressure; C is coefficient of gas solubility in oil, 1/MPa; pressure at bottoms of injection wells are determined from the relation P_inj>P_o+ΔP, where P_inj is bottom pressure in injection wells, MPa; P_o is pressure of start of liberation of gas dissolved in oil, MPa; ΔP is depression produced by producing well, MPa. Injection wells in gas cap and in water-saturated zone are located in corners of rectangles formed by lines connecting nearest injection wells to one another. Rate of water injection through nearest injection wells in gas cap and water-saturated zone are established identical. Producing wells are located at identical distances from two nearest injection wells in water-saturated zone. Distance of row of producing wells from row of injection wells in water-saturated zone is established from relation L₀<l₁≅ 0,5l, where l₁ is distance of producing wells from injection wells in water saturated zone, m; l₀ is distance between internal and external contours of oil bearing capacities, m; 1 is distance between internal contour of gas-bearing capacity and external contour of oil-bearing capacity, m. In so doing, distance of row of producing wells from row of injection wells in gas cap is established larger than than between row of producing wells and row of injection wells in water-saturated zone. Producing wells as they become flooded are transferred for water injection, and bottom pressure of wells transferred for water injection is established from relation P_p>P_o+ΔP, where P_p is bottom pressure of well transferred for water injection, MPa. EFFECT: higher efficiency. 9 cl, 3 dwg