A method of oilfield water injection that can achieve balanced displacement of remaining oil

Abstract

The invention provides an oilfield water injection method capable of realizing balanced displacement of remaining oil. The oilfield water injection method is mainly used for solving the problems of poor oil displacement efficiency and low petroleum recovery efficiency of the existing water injection development applied to a nonhomogeneous reservoir stratum. The method comprises the steps of forming holes in a shaft uniformly and densly, wherein the hole density in the transverse direction of the shaft is determined according to crustal stress, well network, remaining oil and physical properties, and the distance between two rows of holes in the longitudinal direction of the shaft is determeined according to the physical properties of an oil layer during the hole distribution process; carrying out construction according to the distributed holes, and forming a hole in the side direction; arranging a flow rate-adjustable water nozzle in the formed side hole; carrying out underground butt joint between an underground comprehensive testing and controlling meter in an automatic flow rate testing and controlling system and the flow rate-adjustable water nozzle, and adjusting the opening degree of the water nozzle to realize accurate control of the water injection quantity at each point; and beginning the water injection work. When the oilfield water injection method provided by the invention is used for injecting water, water injection quantities at all points are different according to the nonhomogeneity of each point of a reservoir stratum, and therefore, balanced displacement of remaining oil is realized, the water absorption profile of a water well is improved and the oilfield recovery efficiency is improved.

Description

Technical field: [0001] The invention relates to an oilfield water injection and oil displacement method used in the field of oilfield petroleum exploration and development for improving oilfield recovery. Background technique: [0002] Due to the heterogeneity of different layers and different scales in the reservoir, the permeability at each point is not completely the same. There are obvious differences in the interlayer and intralayer seepage characteristics of most of the oil fields in my country. , The injected water flows along the high-porosity, high-permeability zone, large pore throat or fracture, so that the oil and gas in the matrix, low-porosity, and low-permeability zone are produced to a low degree, or even not produced. In addition, the oilfield flooding is serious and uneven, the nature of the injected water changes complex, and the underground fluid properties and stratum structure changes after the oilfield floods. The changes in the physical properties of the ...

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Problems solved by technology

It is precisely because of the above reasons that existing water flooding development methods have the problems of poor oil displacement and low oil recovery when applied to heterogeneous reservoirs.

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