There are many different types of smart well systems such as Inflow Control Valves, Inflow Control Devices and autonomous devices of various designs. The most common inflow system is blank pipe, producing through a screen and into the control valve at the connection sub.
To control the functionalities one may use surface control lines, dropping balls or darts or simply let the valves react autonomously to changes downhole. These tools can be deteriorated by erosion, plugging of fines, plugging of of heavy oil residue or by scaling.
Scaling is a complicated issue as it often builds up near critical parts of the tool, changing the flow pattern and affecting or offsetting the flow assurance. This paper will present a new concept in chemical well injection. It is proposed to connect a capillary tube through the entire completion string to inject chemicals to prevent scaling of critical tools before the oil enters the tool, thereby increasing the time the tool will function.
A new downhole chemical injection valve is developed. It is located near the injection point to prevent U-tube pressure effects often associated with surface injection systems. This injection valve can also easily be adjusted downhole or shut off if required. The advent of water production often changes chemical injection requirements. The new system can accommodate any changes in chemical or flow rates. The system is fully mechanical and does not rely on electrical control cables. Flow regulation is performed through the capillary tube.
The paper will describe the new downhole chemical injection system and its application to smart well technology.