WATER CONING CORRELATIONS IN VERTICAL WELLS

One of the major problems that reduces significantly the crude oil production is water coning.When the well is produced, water moves up from the bottom water toward the wellbore in a cone shape.At certain conditions, water breaks through into the well and concurrent oil and water production starts.Many methods have been presented to overcome this problem, whatever before or after the taking place of water coning.The critical rate is the widely method used to overcome this problem before its occurring.The aim of this paper is to introduce a method to predict the critical rate, breakthrough time, and WOR (water oil ratio) after breakthrough in vertical wells.A 3-D numerical simulator model was used to perform a comprehensive sensitivity analysis of water coning process.From this analysis, an empirical coning correlation was developed based on the basic flow equations and regression analysis.The format of the correlation is similar to Addington's gas-coning and Yang's water coning correlations.The correlations presented in this paper provide a hand calculation fashion of coning prediction for vertical wells.The correlations were tested and found to be reliable and accurate in predicting the critical rate, breakthrough time and WOR, within the correlation parameter range.