Analysis of An Operational Oilfield Supervisory Control System
Authors: Brophy C.E. , Scoles L.R. 
Published: March 2010

This paper analyzes the design, installation and operation of a computer-based supervisory control system located in Amoco Canada leases in the Pembina oilfield. A combination of short-duration well tests and direct surveillance of pumping units is used to monitor producing wells. Wires are also run to service wells to measure well-head pressure, rate and volume as applicable. In addition, the system performs conventional surveillance and reporting functions.

INTRODUCTION

COMPUTER MONITORING and control of oilfield facilities is becoming an accepted operating tool for maximizing production and minimizing operating costs. This paper analyzes the design, installation and operation of Amoco Canada Petroleum Company Limited''s computer production control facilities at Drayton Valley. Alberta.

Amoco Canada currently operates 25% of the more than 4000 wells in the Pembina Field, along with associated waterflood projects and gas plants. Over 400 of these wells are now operating under computer production control. The system was designed with five basic functions in mind.Monitor oilfield equipment. Downtime is minimized by immediate reporting of abnormal conditions. For example, it is now immediately known which producing wells failed to automatically restart after a commercial power failure.Measure and store field flow rates, volumes and pressures. This feature supplied an unexpected benefit when a water injection line break was discovered while checking a high flow rate – low pressure alarm at a water injection well.Automatically shut-in. wells. This feature is used in the event of a battery fire or impending- tank oil spill. Confirming alarms are required from two devices before wells are shut-in by positive, hard-wired control of the prime mover.Perform short-duration well tests. Representative well tests are now available on most wells every 3 or 4 days, as opposed to from 1 to 3 times a month prior to automation.Format and output data. Accurate data are now timely and concise. The time previously spent organizing- and transmitting data is now spent on more productive work.

In addition to these five basic functions, the system is designed to be economical, easily maintained and fail-safe; thus a failure in the telemetry system couses no lost production.

System Description

SCOPE

The system encompasses three basic types of production facilities.In the first type, produced fluids are collected directly from the wells into a treating facility having the capacity to test individual wells.The second type consists of the routing of fluids from a group of wells through a satellite header. There, a well may be singled out and tested in a two-phase separator before rejoining the group and passing on to a central treating facility.In the third type of facility (Fig. 1). fluids from a group of wells are routed to a satellite battery. There, a well may be singled out and tested in a three-phase separator. Group production is passed through another separator, where gas is removed and sold. The liquids are then routed to a central treating facility.