Method for describing extra-high water cut development period weak drive distribution feature of medium-high permeability oil reservoir

Abstract

The invention discloses a method for describing the extra-high water cut development period weak drive distribution feature of a medium-high permeability oil reservoir. The extra-high water cut development period oil reservoir faces the problems that the comprehensive water cut is high (95%), the production decline is large, distribution of underground remaining oil is complicated, scattered and hidden, and injected water ineffectively circulates in the superior direction, so that the utilization rate of the injected water is low. It is difficult for an existing method for describing the remaining oil with saturation distribution to embody the difference of a strong water logging area, quantitative expression of a weak drive area cannot be achieved, and the existing method for describing remaining oil with saturation distribution is not adapted to the need of development in the extra-high water cut later stage. According to the method for describing the extra-high water cut developmentperiod weak drive distribution feature of the medium-high permeability oil reservoir, by means of a water-oil displacement, the weak drive boundaries of cores of different permeability are determined, a numerical simulation technology determines the number of times of displacement of each grid of the macroscopic oil reservoir, and with the permeability as the relevant parameter of a microcosmic experiment and macroscopic numerical simulation, elaborate description of the distribution features of the weak drive in the macroscopic oil reservoir is achieved; and the method for describing the extra-high water cut development period weak drive distribution feature of the medium-high permeability oil reservoir points out the direction of oil reservoir development adjustment in the extra-high water cut development period, reduction of ineffective water injection and improvement of the development effect, and has strong application and popularization value.

Description

technical field [0001] The invention belongs to the technical field of petroleum exploitation, and in particular relates to a method for describing the distribution characteristics of weak flooding in the ultra-high water-cut development period of medium-high permeability reservoirs. Background technique [0002] The higher the recovery rate of rich gas in the process of rich gas flooding, the higher the utilization rate of rich gas and the better the reservoir development effect. Due to the miscible or near-miscible characteristics of the rich gas in contact with crude oil in the formation, the intermediate hydrocarbons in the rich gas continue to melt into the crude oil, and the light components in the crude oil are extracted, resulting in a complex composition of the produced gas, which cannot be simply understood as Inject a mixture of rich gas and dissolved gas. At present, the detection of gas sample composition is mainly through gas chromatography (GBT 13610-2003 gas...

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Problems solved by technology

[0004] Aiming at the deficiencies in the prior art, the present invention provides a method for describing the distribution characteristics of weak flooding during the development period of ultra-high water cut in medium and high permeability reservoirs, aiming to solve the problem that the current method of using saturation distribution to describe the remaining oil is difficult to reflect the strong water flooded area difference, unable to quantitatively characterize the problem of weak water wash (i.e. weak drive area)

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