Closing the Loop for Improved Oil and Gas Production Management

Abstract

Well and Facility Operations make operating decisions based on processing huge amounts of data. However, there is a practical limit to the number of optimization moves an operator can make (due to: changing operating constraints, plant disturbances or interactions, fundamental process delays and dynamics, and the remoteness of wells). Automatic Process Control enhances the speed and accuracy with which decisions can be made and is essential for optimization. However, the advantages of automatic process control are often underestimated; hence the discipline is under-staffed and under-utilized.Process Control also plays a crucial role in plant safety and availability as stable wells or facilities are operated more frequently within the design window. Stable operation results in fewer shutdowns, less breakdown maintenance, less deferment, less flaring, lower operational cost, and sometimes even higher ultimate recovery. The impact of process instabilities on overall well or facility performance are often not recognized; a single trip may wipe out months of optimization benefits.To achieve the full potential of process control in Oil and Gas Production requires change management; Process Control technology skills need to be used throughout the whole projects lifecycle and integrated with the various processes from field development planning to surveillance and optimization. This paper will provide the following examples:1. automatic control of producer wells to prevent coning and/or gas breakthrough, 2. automatic control of injection wells to control water flooding and prevent fracturing, 3. capacity and surge controls for compressor networks, 4. control applications for the suppression of slugs, and, 5. higher level process control applications, where the application of automated control technology has improved production surveillance, management, and optimization. The role of Process Control in Exploration and ProductionHistorical perspective Most engineers and managers confuse Process Control with Instrumentation; i.e. they think Process Control is only about the video screens in the control room and the associated computers. However, Process Control is the rationale behind the visible systems (instruments and valves) and the strategy about realizing process objectives. Design decisions are made when devising the control strategy; if the level in a vessel is higher than the desired level, the control strategy is either to open the valve of the liquid outlet stream or to throttle a valve in the incoming stream. The right choice will depend on the process itself and the process objectives of the integrated facility (i.e. the consequences of the strategy upstream or downstream of the unit must be considered). Certain control objectives will be conflicting or have different priorities. It is also important to consider the dynamics of the process, the drifts and changes in the underlying equipment and processes, the measurement noise, and the possible disturbances that can occur.

Smart De-Watering and Production System through Real-Time Water Level Surveillance for Coal-Bed Methane Wells

“…To maintain the desired operating conditions, this type of feedback controller is frequently used in production and refining processes in the petroleum industry (Wang et al 2000;Havre and Dalsmo 2001;van Dijk et al 2008;Bieker et al 2007;Sengul and Bekkousha 2002;Stenhouse 2006;Oberwinkler and Stundner 2005;Saputelli et al 2005;Nikolaou et al 2006;Guyaguler 2009). The control systems implemented in facilities and refineries have sensors and mechanical equipment to observe and physically modify the process settings.…”