A radio alarm monitoring system, serving eight widely separated leases, has been operated since Jan., 1966, by Pan American Petroleum Corp. in the vicinity of Hobbs, N. M. Twelve oil wells and four gas wells are being served by single-channel transmitters at each lease, with receivers located at the pumper's base station and in his truck. The pumper's work area includes the alarmed leaves and four non-alarm leases. These leases encompass approximately 580 sq mile, with the nearest lease located some 30 miles from the pumper's base station.
As a result of satisfactory operation of this system, labor requirements to pump the leases have been reduced by 40 percent with no loss in production. A radio alarm monitoring system of this type is considered to be a reliable method of reducing operating costs where conditions warrant. This paper discusses the radio equipment in use and the type of alarms installed at different leases to make remote monitoring possible. Also discussed is the field fabrication of a minimum production alarm that has proved reliable.
In early 1964, Pan American Petroleum Corp. considered using alarms on some isolated properties to develop more economic operation. From knowledge of these properties and information on alarm functions and capabilities, it was decided that an alarm system would be designed around the basic idea of the pumper's concentrating his time at the Greenwood unit battery. Alarms would be transmitted from outlying marginal leases to notify him that some operating problem required his attention. By transmitting alarms to a base station, 24-hour surveillance could be maintained, permitting the pumper to schedule his time to visit alarmed points during his regular work day.
One significant location was the northern Delaware Basin area where scattered properties ranged in productivity from high capacity to marginal and where there was a greater potential for reducing labor costs by eliminating contract pumping jobs. Since the properties under study involved various types of production over a large area, careful consideration was given to the number of wells that with proper monitoring, could be handled by one man. Because of the distance from existing telephone lines, radio transmission was considered the best available means of furnishing alarms. This paper discusses the system that was installed.
A pilot installation, operating satisfactorily at the Plains unit battery for 14 months, warranted expansion to the present system. The planned expansion comprised both oil and gas wells (Fig. 1). In reviewing the producing characteristics of these properties, it was apparent that no one set of alarm functions would apply to all leases. Thus, considerable study was directed toward determining the "personality" of a lease to develop the optimum alarm points for remote monitoring.
For the four low-capacity oil leases, the information most desired was whether there had been any production during a specified period of time. To handle this problem, a low-cost, field-fabricated production sensor, to be discussed later, was developed and proved to work. In addition to the production monitor, some alarms developed for these marginal properties were
electric power or gas engine failure and
high stock-tank level to notify the pumper when a tank is full and ready to run.
Because of low-capacity production from these leases, all alarms were considered to be low priority for directing the pumper to those properties only when attention was needed.
For gas wells to be monitored in the system, dehydrators and gas production were considered the critical functions for alarming. A switch indicating differential pressure, installed on the sales meter to record a predetermined, low gas-flow rate, would signal on alarm condition. A glycol dehydrator was in use on the gas sales line. The high and low reboiler temperatures on this unit would be monitored with a temperature switch gauge. Temperatures above 390F and below 300F would activate an alarm signal (the unit normally operates at 340 to 360F). These two alarms were installed on the West Tonto, Mary Nellis and Buffalo No. 4 system at a single transmitter station. Because of the relatively high volume of distillate produced from Emperor No. 1, a high-level stock-tank alarm was incorporated in addition to the low-flow and temperature alarms.
On the higher productivity Plains unit and Big Eddy unit properties, which had six and two wells, respectively, different alarms were incorporated. On the Plains unit, the pilot project where an ACT unit already was installed, alarms were developed that would light the rotating beacon if the ACT failed. In addition, there was an emergency high-level alarm in both the over-flow tank and in the separator to prevent loss of oil to the gas purchaser.
JPT
P. 479ˆ
