Continuous Remote Optimization

The Challenge

Current artificial lift systems have certain elements of control. For example, the Subsurface Compressor System™ (SCS) and the Electric Submersible Pump (ESP) use a variable speed drive (VSD) on the surface to control their motors downhole. There are also other elements in the well system that provide either information or actuation to control the well. For instance, operators install downhole sensors to measure the temperature and pressure of a well at different depths. However, these elements are seldomly linked together to provide better control of the overall system. Even if the information from different elements is used to improve the performance of the well, it is often used on an ad-hoc basis and rarely in real-time remotely. Adverse situations must be handled in real-time in-situ by a system level control scheme to avoid damages to the downhole equipment and to ensure continuous operations of the artificial lift system. There is a need to link all of these elements together to achieve optimal performance of the system.

Why Real-time Autonomous Control 

Without an autonomous system control scheme, as the environment changes, the motors will only respond to the VSD’s control commands, while the bearings will only respond to the magnetic bearing controller’s (MBC) control commands.

For example, if an environmental change affects the bearing performance and can be mitigated by varying the motor speed, then in the current configuration, this action can only be done by an engineer. To avoid damages to the downhole equipment, the engineer notified by the MBC must have the knowledge to analyze the information and make the right decision about what actions to take on the VSD, must have access to change the setting of VSD and must act in a timely fashion. Therefore, for faster response and to eliminate human error, there is a need to have an autonomous control at the system level to protect and optimize artificial lift systems.

Inputs to Autonomous Controller

The inputs to the Upwing autonomous controller include: 

Environment Data provided by downhole monitoring

• Reservoir, suction, discharge and well-head pressures
• Suction, discharge and well-head temperatures 
• Wellhead flow 
• Gas/liquid content from the surface 
• Well characteristics (inflow curves) 

Data from the SCS Tool 

• Speed of rotation 
• Motor lead & VSD terminal voltage and current 
• Motor temperatures 
• Compressor map 
• Vibration 

How It Works

Upwing's autonomous system controller links all the elements to control the whole system without human interference, and in real-time, makes any necessary changes to the operation to ensure safe and optimal operation.

The Upwing autonomous controller continuously monitors SCS health and operating conditions while ensuring the operation is within the SCS's operating margins based on a predetermined control scheme. For any of the elements being monitored that are out of order, the controller is programmed to bring the SCS system to an acceptable operating point without the need for any human intervention. In the meantime, the system controller will also send the information from the sensors to the client so that all relevant warnings or alarms can be reviewed in real-time by an engineer. Additionally, all data is sent and stored in the cloud for engineers to download and review in real-time. 

Upwing can also push the available data in a format and frequency preferred by the client, as well as trigger data reports requested by the client.