Disclosed are methods, systems, and computer-readable medium to perform operations including: generating, based on production data for a wellbore, (i) a water-oil-ratio with respect to time (WOR) dataset for the wellbore, (ii) a time-derivative dataset (WOR′) of the WOR dataset; generating a WOR log-log plot of the WOR dataset and a WOR′ log-log plot of the WOR′ dataset; identifying at least one trend in the WOR log-log plot and the WOR′ log-log plot; determining, based on the at least one identified trend, a first type of water breakthrough; generating, based on pressure data from a build-up pressure test in the wellbore, a log-log plot of time-derivative pressure data with respect to time (P′); determining, based on the P′ log-log plot, a second type of water breakthrough; correlating the first and second type of water breakthrough; and determining, based on the correlation, whether to perform a water treatment for the wellbore.