Abstract: A permeability-enhancing flooding system for tight oil reservoirs and preparation and use thereof are disclosed. The permeability-enhancing flooding system is present in a state of oil-in-water droplet and composed of a surfactant, an oil-soluble substance and water, and has an outer phase that is an aqueous solution containing the surfactant, and an inner phase that is the oil-soluble substance; and the surfactant comprises one of nonionic gemini surfactants and anionic gemini surfactants, or a combination of two or more thereof. The preparation process for the permeability-enhancing flooding system is simple to operate, suitable for industrialized production, and low in overall cost, and has obvious application prospects in the field of tight oil reservoirs for an enhanced oil recovery.

Abstract: Disclosed is a method for determining three-dimensional in-situ stress based on displacement measurement of borehole wall, including the following steps: pumping the prefluid and the sand-carrying fluid into the target interval, and injecting the biological oil displacement agent into the target interval in sequence; pumping temporary plugging agent into the target layer to implement crack plugging diverting; pumping the sand-carrying liquid into the target interval, and injecting the biological oil displacement agent into the target interval. The beneficial effect of the technical scheme proposed in this disclosure is: by injecting oil displacement agent to fracturing fluid, the temporary plugging diverting fracturing is integrated constructed with enhanced oil recovery, at the same time, it can overcome the incomplete removal of temporary plugging agent and the water lock effect of fracturing fluid caused by diverting fracturing.

Abstract: A permeability-enhancing flooding system for tight oil reservoirs and preparation and use thereof are disclosed. The permeability-enhancing flooding system is present in a state of oil-in-water droplet and composed of a surfactant, an oil-soluble substance and water, and has an outer phase that is an aqueous solution containing the surfactant, and an inner phase that is the oil-soluble substance; and the surfactant comprises one of nonionic gemini surfactants and anionic gemini surfactants, or a combination of two or more thereof. The preparation process for the permeability-enhancing flooding system is simple to operate, suitable for industrialized production, and low in overall cost, and has obvious application prospects in the field of tight oil reservoirs for an enhanced oil recovery.

Abstract: Disclosed is a method for determining three-dimensional in-situ stress based on displacement measurement of borehole wall, including the following steps: pumping the prefluid and the sand-carrying fluid into the target interval, and injecting the biological oil displacement agent into the target interval in sequence; pumping temporary plugging agent into the target layer to implement crack plugging diverting; pumping the sand-carrying liquid into the target interval, and injecting the biological oil displacement agent into the target interval. The beneficial effect of the technical scheme proposed in this disclosure is: by injecting oil displacement agent to fracturing fluid, the temporary plugging diverting fracturing is integrated constructed with enhanced oil recovery, at the same time, it can overcome the incomplete removal of temporary plugging agent and the water lock effect of fracturing fluid caused by diverting fracturing.