Abstract: The invention discloses a method for determining vertical well stratified fracturing crack length based on interlayer equilibrium development. According to the method, interlayer equilibrium development can be achieved by determining the crack length of fracturing of each layer in the condition that an oil well meets the productivity requirements. The method comprises the following steps: 1) a threshold pressure gradient of each layer is determined; 2) a relationship chart of the crack half-length xf and the equivalent well diameter rwe is established; 3) daily oil production rate per unit thickness Qc meeting the production requirements is calculated; 4) the equivalent well diameter rwe of each layer is calculated according to the daily oil production rate Qc; and 5) the crack half-length xf of fracturing of each layer is calculated according to the equivalent well diameter rwe of each layer.

Abstract: The present disclosure relates to a method and system for determining a technical limit well spacing for chemical flooding for a heavy-oil reservoir. This method includes: establishing a reservoir numerical simulation model; setting up injection and production wells according to a set well spacing, and using the reservoir numerical simulation model to calculate an average pressure, an average crude oil viscosity and an average permeability at each grid point between the injection and production wells within m days; calculating a driving pressure gradient of each grid point, and drawing a driving pressure gradient curve; calculating a starting pressure gradient of each grid, and drawing a starting pressure gradient curve; determining a relationship between the driving pressure gradient curve and the starting pressure gradient curve. In this manner the present disclosure calculates the limit well spacing for chemical flooding for the heavy-oil reservoir after steam stimulation.

Abstract: The invention discloses a method for determining vertical well stratified fracturing crack length based on interlayer equilibrium development. According to the method, interlayer equilibrium development can be achieved by determining the crack length of fracturing of each layer in the condition that an oil well meets the productivity requirements. The method comprises the following steps: 1) a threshold pressure gradient of each layer is determined; 2) a relationship chart of the crack half-length xf and the equivalent well diameter rwe is established; 3) daily oil production rate per unit thickness Qc meeting the production requirements is calculated; 4) the equivalent well diameter rwe of each layer is calculated according to the daily oil production rate Qc; and 5) the crack half-length xf of fracturing of each layer is calculated according to the equivalent well diameter rwe of each layer.