Theory And Application On Nonlinear Porous Flow In Low Permeability Reservoir

In order to exploit low permeability reservoir so much the better, the paper studies threeelements, which the fluid percolated in the low permeability reservoir. These elementsinclude permeability of the porous medium, the percolating fluid of viscosity and net-paythickness of oil formation. And the research achievement of predecessor is summed up fully.On the base of in-house experiment, theoretical analysis, analysis the characteristic of thefluid flowing through porous medium in the low permeability reservoir, and find the equationof motion, which the fluid runs in the low permeability reservoir. This paper has beencompleted the following researches:1. Choosing three kinds of core samples, which permeabilities are < 1 ×10^-3μm²,1-5 × 10^-3μm², > 5 ×10^-3μm²respectively, the experiment describing the flow ofsingle-phase oil, gas and water fluid are conducted. The relation curve of oil or waterpermeability decreasing percentage vs. gasometry permeability and oil or water thresholdpressure gradient vs. gasometry permeability are drawn. The core seepage flow experimentsshow that the smaller the permeability of core, the bigger permeability decreasing percentageand the bigger the start-up pressure gradient, which the fluid flow in low permeabilityreservoir.2. The flow experiment of water-flooding has been conducted., which the choosing partof core samples are involved in the three kinds of core samples. The curves of relativepermeability are drawn, and the characteristics of oil-water relative permeability are analyzed,and comparing with the middle-high relative permeability. By comparing, the features ofoil-water flow in the low permeability container rock are gained. Combining with practicalproduction in the oil field, the based production characteristics are analyzed and obtained,when the low permeability oil field is exploited by water.3. By the hand of the equation of motion and the fundamental differential equationpercolating in the single well, the formulae of well yield and pressure distribution can be ledoff, when the fluid percolates in the low permeability reservoir. By the derived formulae ofwell yield and pressure distribution, the variable disciplinarian of oil production and pressuredistribution, when the permeability, viscosity, flow coefficient, mobility are different, aregained. It is the theoretical basis that the seeping rule is analyzed and studied in the practicalprocess of production.