| abstract |
A method is described for recovery of a hydrocarbon fluid from a porous medium by injection of a fluid into the porous medium. The method includes determining a Rayleigh time on the basis of the density of the fluid and the hydrocarbon fluid, the median pore diameter of the porous medium, and surface tension between the fluid and the hydrocarbon fluid. Further, pressure stimulation is provided in the fluid and generated by a collision process with a collision contact rise time which is of the range of 1-100 times the Rayleigh time. Alternatively or additionally, the providing a pressure stimulation in the fluid include generating an impact pressure with a pressure amplitude I and a pressure rise time Δt, where the pressure amplitude is larger than the relation γcΔt/a 2 , where γ is the surface tension between the fluid and the hydrocarbon fluid, and c is the speed of sound in the porous media. In aspects of the invention, the method includes arranging a chamber in fluid communication with the porous medium via at least one conduit, and having the chamber comprising first and second wall parts movable relative to each other. The pressure stimulation includes providing an impact pressure in the fluid to propagate to the porous medium via the conduit, and where the impact pressure is generated by the collision process between an object arranged outside of the fluid and the first wall parts for the first wall part to impact on the fluid in the chamber. |