Field Validation of a Non-logging Alternative Method for the Prediction of the Location of Water-Cresting in Horizontal Wells for Water-Drive Reservoirs.

Abstract

A previously reported method for a non-logging alternative method for the prediction of the location of water-cresting in horizontal wells for water-drive reservoirs is validated in a field test for the first time in this study. Using this method, the wellbore trajectory, variation in the reservoir permeability, and the pressure gradient data were used to calculate what is called the breakthrough coefficient for the different segments along the length of a set horizontal well with the largest calculated breakthrough coefficient corresponding to the most likely location of the actual water-cresting occurrence. This method was field-validated and found to be in good agreement with log testing for a group of seven wells in an oilfield in Northern China. Another calculated parameter derived from the breakthrough coefficient which is called the variation of the breakthrough coefficients that characterize the effect of the variation of water production along the length of the horizontal well due to the effect of the variation of the wellbore trajectory, permeability, and pressure gradient on the oil production is also introduced. This field validation found variation of the breakthrough coefficients to be weakly and inversely correlated to the oil production in application to a group of 27 wells in the same field.