FM Radio Splinter Frequency as Used in An Alarm-Status and Data-Gathering Supervisory System
Authors: Westbrook G.H. , Roberts S.C. 
Published: December 2007

This intermediate supervisory system employs a band-edge frequency for performing control and data-gathering functions. It should appeal performing control and data-gathering functions. It should appeal particularly to the small operator and to the major with properties that particularly to the small operator and to the major with properties that need supervising but that are too marginal to warrant a full-scale system.

Introduction

The petroleum industry today finds itself in an ever-increasing plight to produce a more economical barrel of oil. To accomplish this, large, computer-controlled field installations have been developed and have made significant contributions toward an improved profit picture in the larger operational areas. What profit picture in the larger operational areas. What about the smaller operational areas, those that cannot economically justify such complete and complex installations? Continental Oil Co. has tried to fulfill these needs by implementing, wherever practical, these lower-level alarm-status and data-gathering systems. Earlier systems include radio alarms and the Four Corners Area Alarm System with transmission by telephone wire. The system described here was initially patterned after the Four Corners System. The establishment of "excessive" construction charges for the telephone linkage between satellites dictated that another mode of transmission be developed for the sake of economy. The word excessive as used here does not imply that the telephone company construction charge was excessive for such work; rather it indicates that additional capital investment would have made the economics of the project questionable. Conoco Communications, Inc., being aware of the construction charge through negotiations with the telephone company, recommended investigation of the "band edge", or-splinter frequency. A similar system had been granted a developmental license to operate in the Gulf Coast area. Application was made and authorization obtained for 173.20375 MHz and 173.39625 MHz band-edge frequencies for use in a telemetering and control operation. These frequencies, with a 7.5 KHz channel band width, had been previously authorized by the FCC for developmental previously authorized by the FCC for developmental purposes. Operational problems, to be discussed later, purposes. Operational problems, to be discussed later, indicated a need for a different transmitting frequency between the satellites and the master. The 173.39625 MHz frequency was changed to 154.47125 MHz upon granting of a Special Temporary Authority. Continental employs this splinter frequency alarm-data supervisory system in the Denver-Julesburg basin southeast of Fort Morgan, Colo. (see Fig. 1). The system performs the surveillance and data-gathering functions on 54 producing wells in four separate fields. The master is located at Little Beaver, and satellites are at Bobcat, Plum Bush, and Big Beaver fields, from 6 to 7.3 miles from the master. During 1967, the year of installation, the combined producing rate from all fields averaged approximately 2,650 BOPD.

System Components and Description

The system is composed of normal automatic lease equipment (LACT, test headers, floats, etc.), a master control console, satellites, a splinter frequency radio channel, a telephone link, an answering service, and a normal voice band radio channel. The lease equipment, telephone link, answering service, and voice band radio channel are common types and will not be discussed.

JPT

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