Automation of Oilfield Engine Prime Movers
Authors: McCune M.K. 
Published: December 2007

Automation of oilfield engine prime movers is directly related to the over-all concept of automation in the oil industry because it makes possible the direct use of liquid or gaseous fuels, which are a primary product of this industry. This paper discusses the necessity of developing oilfield engine automation, its evolution, principle of operation, general application, equipment limitations and requirements for establishing a successful engine automation program. program. Introduction

The over-all economics of oilfield operation has prompted a move toward automation in many phases of the oil prompted a move toward automation in many phases of the oil industry. We now speak freely of systems of centralized supervisory control, either manual or computerized. These systems control entire producing oil fields, pipeline systems, or processing plants through remote start and stop control systems with accompanying data gathering and data processing equipment. processing equipment. Emphasis has been placed upon the development of unattended automatic operation of oilfield engines because of savings realized by the direct use of the primary fuels, which are a basic product of the oil industry. For the past several years, manufacturers of industrial engines and associated controls and instrumentation have been actively developing and marketing full range engine automation systems tailored to oil industry needs.

Evolution of Engine Automation

We tend to think of engine automation as a relatively new development. However, although the development of some control functions required in oilfields is relatively new, the basic concepts of automatic engine control are almost as old as the internal combustion engine itself. Safety devices for the protection of engines in unattended operation have existed for many years; however, these devices merely stop- the engine automatically in the event of a malfunction.

The need for equipment that could start an engine automatically on demand and that could apply load automatically was primarily presented by the "emergency standby" equipment market. This market includes power generators, flood control units, manufacturing facilities and other fields where power failure constitutes a physical or financial hazard. Control systems for these applications do not have the full range of functions required by the oil industry. The application of load to the engine is relatively simple. Warm-up before load application normally is not required; in fact, in most cases. it is undesirable because immediate replacement of the service that has failed is the basic function of such equipment.

Automated operation of oilfield engines has extended the control function beyond "emergency standby" to include engine warm-up, clutch control, engine cool-off and full engine and system safety switch protection - all in addition to automatic starting and stopping.

Principle of Oilfield Engine Automation Principle of Oilfield Engine AutomationRequisites of functional engine automation systems for the oil industry are:Standardized control packages suitable for installation on existing "in service" oilfield power units as well as on new equipment.Programmed cranking.Timed warm-up at idle speed under no load.Load connection and disconnection (normally, engagement and disengagement of the clutch-power take-off).Timed cool-off at idling speed under no load.Full safety switch protection of both engine and system equipment.Ability to start and stop upon demand with no control system power drain during "off" periods.Enclosures and fittings that provide protection from weather and dusty and corrosive atmospheres, and explosion-proof systems available for special application.Utilization of control power sources that are normally available at isolated locations or that can be made available easily and economically.A high degree of reliability and repeatability under all oilfield conditions."Fail safe" design.

Several companies are actively marketing oilfield engine automation systems. However, for the past 10 or 12 years, one engine manufacturer, one controls manufacturer and one engine distributor have been especially active in developing and applying these specialized automation systems through field installation and evaluation. From this development program two basic automation concepts have evolved, full-electric and full-pneumatic.

JPT

P. 1115