65results about How to "Reduce surface and interfacial tension" patented technology

The invention discloses a compound microorganism oil extraction method for a low permeability oilfield. The compound microorganism oil extraction method comprises the following steps of (1) cultivating pseudomonas aeruginosa YM4 strains and pseudomonas stutzeri DP1 strains in an indoor shaking flask respectively, and obtaining fermentation broth of high-activity pseudomonas aeruginosa YM4 strains and fermentation broth of polymer produced strains through first-stage and second-stage seeding tank amplification and fermentation production of a production tank; (2) mixing surface active agent produced strains and the pseudomonas stutzeri DP1 strains fermented and produced in the step (1) according to volume ratio of 1:1; and (3) enabling compound microorganism bacterium liquid obtained in the step (2) to serve as an oil-displacing agent to inject in an oil layer directly through a water injection well, and obtaining crude oil from a producing well. The YM4 strains and the DP1 strains are both facultative anaerobic microorganisms and can both grow and breed in a ground layer, polymers produced by the DP1 strains can improve mobility ratio, increases water injection affecting area, and the product surface active agent of the YM4 strains can reduce oil-water interfacial tension and improve oil recovery.

The invention discloses a fracturing prepad fluid, comprising the following ingredients: 1-10 wt% of biological enzyme, 0.1-1 wt% of clay stabilizing agent, 0.01-0.1 wt% of fluorocarbon surfactant, 0.01-0.5 wt% of wettability reversal agent, 0.01-1 wt% of composite activator, and the balance of water. The fracturing prepad fluid disclosed herein not only overcomes the disadvantages of routine prepad fluids and has the advantage of fracture forming of routine prepad fluids, but also has the effects of peeling off residual oil on the surface of a rock core, cleaning and unblocking oil gas seepage channels, reducing the viscosity of crude oil, changing the wetability of the rock core, reducing the surface and interfacial tension to benefit for flowback, and preventing the clay from expansionand migration, and the like. The more the fracturing prepad fluid enters a reservoir, the larger the spread range is, and the larger the action scopes of the fracturing prepad fluid on cleaning and unblocking of the oil gas seepage channels are. The fracturing prepad fluid is beneficial for increasing the oil gas yield.