Downhole Water Sink (DWS) technology has been developed from a new well completion and production method for enhancing productivity of wells in petroleum reservoirs with bottom water drive and strong tendency to water coning. DWS minimizes water invasion to the well's completion by employing hydrodynamic mechanism of coning control in-situ at the oil-water or gas-water contact. The mechanism is based upon a localized water drainage generated by another well completion (downhole water sink) installed in the aquifer beneath the oil-water or gas-water contact. The paper summarizes the development and state-of-the-art at DWS technology. Presented are results from theoretical studies, physical and numerical experiments, and field projects to date. It is demonstrated that DWS could increase recovery and control water production in vertical and horizontal oil wells - with natural flow, downhole pumps or gas lift, and in the gas wells from low-pressure tight gas reservoirs. Although by now DWS has been used in reservoirs with bottom water, theoretically the technology is also applicable in dipping structures with encroaching side-water