Computer Production Control Development in North Midway-Sunset
Authors: Williams J.B. 
Published: December 2007

This paper was prepared for the 43rd Annual California Regional Meeting of the Society of Petroleum Engineers of AIME to be held in Bakersfield, Calif., Nov. 8–10, 1972. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon requested to the Editor PETROLEUM ENGINEERS JOURNAL is usually granted upon requested to the Editor of the appropriate journal, provided agreement to give proper credit is made.
Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers Office. Such discussions may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines.

Abstract
Chanslor-Western Oil and Development Company's Production System Monitor, PSYMON is a computer-directed well test system which became operational in January 1971 and now monitors about 20,000 bbls of produced crude per day from over 700 cyclic steam, steam drive and insitu producing wells in the North Midway-Sunset Field. PSYMON was built around existing field hardware which was developed between 1964 and 1970 as a manually operated system that includes centralization of produced fluid handling, fluid metering and BS and W measuring equipment, and electromechanical device control. These end-device centers called Remote Field sites are controlled by an electronics system which utilizes audio-tone serialized communications between a central mini-computer control unit and a number of Remote Field Units containing the memory and logic necessary to perform well tests on a selective basis. Due to modular design the system is easy to maintain and expand and can handle virtually any conceivable end device. Because it is organized with remote memory the system is asynchronous and can tolerate intermittent communications failure without loss of field data. A unique feature in this system is a manual control unit which can duplicate any computer command and also transmit other commands used in Remote Field Unit troubleshooting. Normal reporting and control are via teletype.
PSYMON has operated for over one year with a high degree of reliability and good accuracy. The total investment was modest and will be easily returned by the decreased operating cost and increased production which has been evidenced during the first years operation. The system is considered a success and will be expanded as economics dictate.

Introduction
Over the past eight years Chanslor-Western Oil and Development Company, an independent oil producer owned by Santa Fe Industries, has producer owned by Santa Fe Industries, has operated one of the most successful cyclic steam projects in the San Joaquin Valley at North projects in the San Joaquin Valley at North Midway-Sunset and their move to computer production control evolved as a result of their proven production control evolved as a result of their proven well-by-well approach to thermal recovery project analysis. Originally developed as a well project analysis. Originally developed as a well test system, the Production System Monitor, PSYMON, is now potentially expandable in size PSYMON, is now potentially expandable in size and function to whatever degree necessary to meet the needs of the future as oil recovery techniques and associated hardware become more sophisticated.