The Research Of Oil-water Seepage Rule And Water-flooding Mechanism Of Shanshan Oilfield

A comprehensive study has been made on the problems of low permeability oilfield. This dissertation presents the development of a study on seepage mechanism and recovery technology of low permeability oilfield in Shanshan. The specific tasks achieve in this work include the following:Choosing three kinds of core samples, which permeabilities are below one millidarcy, one to five millidarcy, above five millidarcy respectively, the experiment describing the flow of single-phase oil, water fluid are conducted. The relation curve of oil or water threshold pressure gradient vs gasometry permeability are drawn.The core seepage flow experiments show that the smaller the permeability of core, the bigger the start-up pressure gradient, which the fluid flow in low permeability reservoir. Influences of supply radius and permeability on production of low permeability oilfield are studied. The distribution of formation pressure is described and the limits of production pressure difference under different supply radius are given.The flow experiment of water-flooding has been conducted, which the choosing part of core samples are involved in one to ten millidarcy of core samples. The curves of relative permeability are drawn, and the characteristics of oil-water relative permeability are analyzed, and comparing with the middle-high relative permeability. By comparing, the features of oil-water flow and factors influencing the curves of relative permeability in the low permeability reservoir are gained. Combining with reservoir engineering methods and practical production in the oilfield, the based production characteristics are analyzed and obtained, when the low permeability oilfield of Shanshan is exploited by water.Oil displacement mechanism of cyclic water flooding is studied systematically by utilizing shop experiment of cyclic water flooding. Findings indicate that cyclic water flooding can enhance water drive recovery efficiency one hundredth to four hundredth in Shanshan oilfield. Oil displacement mechanism of activity water is studied systematically by utilizing shop experiment of activity water. Through the analysis, sodium dodecyl benzene sulfonic acid of zero point three percent concentration is the best injectant of Shanshan oilfield. It can enhance five point four six percent recovery.