Method for predicting recovery percentage and water cut of oil field

Abstract

The invention belongs to the technical field of oil exploitation and particularly relates to a calculation method for predicating recovery percentage and water cut of an oil field. The method for predicting the recovery percentage and water cut of the oil field comprises the following steps of: (1) obtaining a water-oil mass ratio: Qw / Qo, i.e. Fg; (2) obtaining the initial oil saturation: Soi; (3) testing the irreducible water saturation: Swi; (4) obtaining a crude oil volume factor Bo; (5) putting the above parameters into a formula as shown in the specification so as to obtain a relationship between the water cut and the recovery percentage. According to the method for predicting the recovery percentage and water cut of the oil field provided by the invention, a universal method applicable to water-flooding development of reservoirs with high-permeability, low-permeability and ultra-low permeability is obtained, and the actual changing rule of the water cut and recovery percentage of reservoirs and the percolation characteristic representation of the oil reservoirs of different types can be reflected, therefore the method is fit for the practical situation better; furthermore, the development index prediction precision can be improved, therefore the method has an important practical significance on the production practice of the oil fields.

Description

technical field [0001] The invention belongs to the technical field of petroleum exploitation, in particular to a calculation method for predicting oilfield recovery degree and water content. Background technique [0002] The water flooding characteristic curve is one of the most important methods in domestic oilfield development evaluation, water cut and recovery degree prediction. The water flooding characteristic curve can comprehensively reflect various influencing factors of water flooding development oilfield, and can be expressed by a relatively concise relational expression, It is one of the most practical and important methods for evaluating the effect of water flooding development and predicting water flooding geological reserves and recovery factors in domestic oilfields. [0003] At present, the water flooding characteristic curves commonly used in most oilfields in China are mainly based on the application of empirical formulas. Domestic scholars also mainly con...

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Problems solved by technology

However, the water drive curve formula obtained by the statistical method has certain limitations, mainly in the following three aspects: First, the corresponding prediction formula is required for different permeability types of reservoirs, which requires a lot of time and effort to analyze a large number of oilfield blocks. Statistical and analysis of the data, derivation of the water drive curve formula applicable to different permeability types of reservoirs; second, the water drive curve formula derived through statistics cannot fully reflect the change law of water cut and recovery degree of the actual reservoir, Moreover, it cannot reflect the seepage characteristic law of this type of reservoir; third, the water drive characteristic curve formula obtained by statistical method regression, due to some artificial data orientation problems in the data statistics process, reduces the data availability and applicability, which To a certain extent, it will have a greater impact on the prediction results of oilfield development indicators, and even contradictory conclusions

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