Application of an Alarm and Data Telemetering System For Production Control
Authors: Tibbits T.J. , Sprouse T.R. , Weaver E.G. 
Published: December 2007

An alarm and data telemetering system was installed in the 30-year-old London field, Illinois, to monitor producing operations. Basic system components include

sensing devices, located at waterflood plants, produced water gathering sites, LACT units, tank batteries and lease headers, transmission equipment consisting of field transmitting stations and a telephone cable system, and base station equipment that includes a digital computer.

Alarm sensors are on-off switches installed on electrical loops terminating at field transmission stations. Each transmitting station scans 16 alarm loops and reports the status of each to the base station via an underground network of telephone cable. Oil production and waterflood plant discharge pressure are also transmitted to the base station. Rapid detection of field malfunctions is possible with the computer that is also used to accumulate and report daily and monthly production data. Improved operational efficiency afforded by alarm and data telemetering permitted application in the established, relatively old London field.

Introduction

An alarm and data telemetering system was incorporated into producing operations at London field, Illinois, approximately 80 miles east of St. Louis, Mo. The computerized London system was engineered to improve over-all operational efficiency. To accomplish this objective the system performs three basic functions. It monitors

operational status of 1,200 potential problem locations, oil production through lease automatic custody transfer (LACT) units and discharge pressure at waterflood injection plants.

Installation of the alarm and data transmission facility has allowed more efficient use of field personnel since manpower is now essentially relieved of searching for problems, and is directed to the tasks of preventive maintenance and rapid correction of problems when they do occur. This application of alarm and data transmission techniques is significant because London is an older field, in the latter stages of secondary depletion.

London was discovered in Oct., 1937, developed on 10- and 20-acre spacing and produced on primary until 1950 when the first waterflood pilot was initiated. Production is from formations of the Chester series, Mississippian system, which, in this area of the Illinois basin, are found at a depth of approximately 1,500 ft. Waterflood operations in the field include 319 leases that extend over an area of about 60 sq miles. Oil production from 924 pumping wells is currently sold through 64 LACT units and 87 conventional tank batteries. Produced water is gathered at 18 sites and pumped to 747 water injection wells from 14 waterflood plants. Eleven water source wells also are used to make up required water injection volumes. Currently, 165,000 bbl of fluid are being handled each day.

The London alarm and data telemetering system can be divided into three basic parts: field alarm and data sensors, transmission equipment and base station equipment. All alarm and data sensors are owned and maintained by Humble Oil and Refining Co., while transmitting and base station equipment are owned and maintained by a local telephone company and leased to Humble.

Alarm and Data Sensors

Alarm sensors installed at London are mechanical-electrical devices that reflect only on-off conditions. Mechanically, the sensors vary depending on the application. Electrically, the sensors are switches that are closed under normal operating conditions. Alarms are indicated when the switches open.

Twelve hundred points are alarmed at five basic types of installation throughout the field.

JPT

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