East Rainbow Supervisory Control System
Authors: Wilson N.D. 
Published: March 2010

Mobil Oil Canada, Ltd. has installed a solid-state Supervisory Control System to operate its producing facilities 20 miles east of Rainbow Lake in northern Alberta. The system utilizes a small computer, located at the main battery in the center of the oilfield. as its nucleus. Through the medium of logic programmed into the computer the functions of alarm monitoring, data gathering, direct control and report preparation are exercised over twenty one oilwells and various water and gas injection facilities.

This paper describes the design and operation of this Supervisory System. It also reviews the performance of the various equipment since its installation in August 1970.

Introduction

THE EAST RAINBOW AREA, located 400 miles north of Edmonton, is a geographic extension of the main Rainbow oilfields in the general Rainbow Lake area of northern Alberta. Mobil Oil Canada drilled its first successful well in East Rainbow during the summer of 1965. Today, it produces an average of 15,000 barrels per day from twenty-one wells in eighteen separate pools; 90 per cent of this production is from the Middle Devonian Keg River Formation. Four satellites located about the field serve to funnel the oil through flowlines to the central Battery 10 complex (Figure 1). This complex consists of the main central treating station, a water injection plant, a produced water disposal station and two 800-hp gas conservation compressors. An aerial view of these facilities is sho1rvn in Figure 2. Pressure maintenance is carried out by injecting water into seven pools and the produced gas into one pool.

A Supervisory Control System for Mobil's East Rainbow properties was first proposed in the summer of 1968. Its intended purpose: to minimize operating manpower in this remote area by placing the Battery 10 complex and the four satellites under the continuous supervision of a computer. A secondary intention was to have this system serve as a possible prototype for future :Mobil automation projects in the far north and offshore areas. The availability and/or reliability of communication links in these areas, particularly in the early stages of an oilfield's development is often a deciding factor when considering the attractiveness of automation investments.

It was recognized early in the project that to properly satisfy the proposed objectives of the System, a small digital computer would be required in the field. During the winter of 1969–70, the end devices needed under an automated production scheme were installed throughout the field, and with the delivery of the Supervisory System hardware in August 1970, the over all System first became operational in September of last year. After the initial start-up and debugging problems were dispensed 'with, the performance of the Supervisor System, specifically the computer, has lived up to its original expectations. In the process, the concept of placing a computer in the oilfield has been shown to be entirely feasible.

Ultimately, the computer will calculate the individual pool allowables and automatically adjust the well chokes as required.