Abstract
In heavy oil fields, well longevity is limited by water inflow. Passive inflow control devices (ICDs) are effective in terms of balancing production flow and delaying the onset of water production. Nevertheless, when gas and/or water breakthrough occurs, a passive ICD enables production of the unwanted fluid. Autonomous ICDs can provide additional restriction to the unwanted fluids and can further enhance the production of oil.
The fluidic diode autonomous ICD is functionally based on fluid dynamics technology in which internal geometry directs flow movement based on the viscosity of the fluid. The autonomous ICD enhances oil production while restricting water and gas influx, without the requirement of intervention or moving parts within the device. The result is improved sweep efficiency, which can extend well life and thereby assist in reducing operating costs. Effective design of an autonomous ICD completion is aided with an accurate prediction of the flow behavior through the device. This paper describes flow testing and field performance of a fluidic diode autonomous ICD optimized for the production of very heavy oils with a viscosity above 150 centipoise (cp), while restricting water and gas production.
The test results of the autonomous ICD demonstrate that the fluidic diode can produce more oil while restricting water. In fact, heavy oil can flow at a higher rate with less pressure drop than water. Flow performance of this device has been characterized by measuring the pressure drop versus the flow rate at differing viscosities, confirming that the autonomous ICD effectively restricts undesired fluids, while enhancing the production of oil. Numerical simulations demonstrate an improvement of water reduction by more than 50% compared to standalone screen completions. This technology has been used to promote oil production and restrict water influx in fields where the oil viscosity is greater than 700 cp. This paper also demonstrates the appropriate design philosophy when determining the suitable application of the technology to help maximize oil recovery and minimize water production.
Fluid flow performance is what truly distinguishes the autonomous ICD from other devices. This fluidic diode autonomous ICD is a robust, reliable solution with no moving parts, nor the requirement of intervention of any kind. Its predictable flow performance has been proven through testing, modeling, and field application.
