A New Model for Predicting Water Cut in Oil Reservoirs

Abstract

Water cut is an important parameter in reservoir engineering. For example, water cut data may be used for the estimation of reserves and ultimate oil recovery as well as reservoir surveillance and management. However it is difficult to predict water cut in water flooding reservoirs. Simulation technique could be used to forecast the water production, but it is time consuming, expensive, and often require information that is not readily available. Fractional flow analysis can easily be conducted using only a spreadsheet. However, most of the traditional models represent water cut as a function of cumulative oil production instead of production time. Note that cumulative oil production itself needs to be estimated or predicted. To this end, we derived a new model that correlates water cut and production time in oil reservoirs. It is easier to predict water production and estimate the performance as a function of production time when using this new model than when using traditional ones. The proposed model has been tested using production data from many oil wells and several reservoirs with a wide permeability range. The results have demonstrated that the proposed new model works satisfactorily in most of the cases studied.

Development prediction and the theoretical analysis in the ultra-high water cut stage for water-flooding sandstone reservoirs

“…There have been plenty of papers on models for predicting development performance such as oil production and water cut (Li et al 2011;Agarwal 1998;Haavardsson and Huseby 2007;Li and Horne 2005). However, less attention has been given to forecasting sweep efficiency and oil recovery.…”

Comparison of Models Correlating Cumulative Oil Production and Water Cut

“…Lawal et al [15] categorized these fw -Np models into three main types: (1) using fractional flow theory, in which rela tive permeability functions are approximated to establish water cut (or water-oil ratio) variation with oil recovery [2,16,17]; (2) using the Arps model [18] and its modifications, for example, semilog water cut versus oil recovery; and (3) using observed trends, for example, linear relationship between water cut and oil recovery. Li et al [19] derived a new model that correlates water cut and production time, instead of cumulative oil production, in oil reservoirs.…”

Dynamic tracking model for the reservoir water flooding of a separated layer water injection based on a well temperature log

“…For a water-flooded reservoir, water saturation, and water cut are key indices used to evaluate the reservoir water-out behavior as well as to monitor and manage the reservoir (Guo and Sun 1998;Li et al 2011;Kazeem et al 2007;Yang et al 2006).…”

“…This method includes an established water-cut prediction model using Neural Networks (Tang and Luo 2003), Usher Model (Yang 2008), Weibull Model, Warren Model, and Rayleigh Model (Liu et al 2009) based on the reservoir static and production dynamic data; an established formula by fitting the plot of water cut with experimental data (Liu et al 2011); and an established quantitatively characterized model of variations in water cut based on the actual water cut and the quantitatively characterized model principles (Zhao et al 2010). Analytical approaches embrace the water-cut prediction method based on the water saturation function and fractional flow theory (Ershagi and Omoregie 1978;Sitorus et al 2006;Lo et al 1990;Ershagi and Abdassah 1984), the mathematical correlation model between the water cut and time established based on making certain assumptions for the reservoir (Li et al 2011;Kazeem et al 2007;Jiang et al 1999), and the analytical solution to the water cut established by calculating the complex potential and portraying flow streamlines in a flooding pattern . These methods are unsuitable for the prediction of the water cut for a reservoir with a separated layer water injection.…”