Design Of Bilateral Water Sink Wells Using Dual Electrical Submersible Pumps To Control Water Cresting In Horizontal Wells

Water coning is a term used to describe the mechanism underlying the upward movement of water in the Perforations in a production well.Coning can seriously affect the well productivity and influence the degree of depletion and the overall efficiency of recovery of oil deposits.Coning is mainly because of the result of the movement of reservoir fluids in the direction.of least resistance area,balanced by the tendency of fluids to maintain the gravity balance.The analysis can be done about gas or water.A review of the literature shows that the vast amount of research has been conducted based on experimental studies to analytical studies and numerical simulation in order to understand and predict water coning and cresting in vertical and horizontal wells.Previous work was mainly concentrated on analytical solution and empirical correlations to predict the conditions that prevent water coning and cresting.Present day work mainly involves numerical simulations in order to simulate the phenomenon of water coning in a specific reservoir.The pressure drop in the reservoir is one of the key reasons for water and gas coning.This pressure drop causes water cresting in water oil contacting in the adjacent horizontal wells.Volume of water coning in horizontal wells is greater than vertical wells and water cut after water breakthrough will increase enormously.In the heel of the horizontal wells,the pressure drop is greater than the toe,so that the water cone at the heel speedily enters the well.The method for controlling water cresting is dual completion to distribute the pressure symmetrically in the wellbore.In horizontal wells pressure gradient causes asymmetric distribution of pressure and inflow.Therefore,to get a symmetric distribution of pressure and increase oil production,we have to work on some techniques which can minimize and avoid happening water cresting in horizontal wells.Two horizontal wells drilled horizontally on top of each other with the upper section directed at the top of the oil zone,and the lower section directed a few feet underneath the original oil-water contact.This method will be called “the Bilateral Water Sink(BWS)technology.In the BWS technique,the well above in the oil zone produces water-free oil and the bottom well which is directed in water zone produce water through artificial lift using ESPs,thus avoiding a water breakthrough in the above well,by keeping the top oil rate below the critical rate.As a result,Water cresting can be totally eradicated,and which will eventually improve oil recovery.“Furthermore”,besides producing water with the oil,BWS splits the two production streams,so water produced is oil free and need to minimum treating preceding disposal.BWS may also empower water to play an important role as a drive mechanism away from the well,thus stimulating primary production and recovery of oil from the well.