Paper: Lightning Protection For An Oilfield Automation And Instrumentation System

For many years, the problem of protecting electrical systems from lightning discharges has plagued power and communications engineers. Only within the past few decades has lightning been a problem to engineers dealing with electrical power systems in oilfields. The problem of lightning protection in West Texas oilfields is unique due to the high concentration of elevated high-voltage lines above flat plains that attract lightning discharges. Most modern, electrically operated oilfields have power-distribution systems that are well protected from lightning discharges; in many cases, the systems are isolated by sectionalizers and other devices. Even if a portion of a field is disabled by lightning damage, the remainder of the field continues to function normally. This paper, therefore, concentrates on protecting the low voltage electronic-instrument systems that are very susceptible to even minor voltage surges caused by lightning. In the last several years, the tremendous expansion of oilfield automation and electronic surveillance equipment has required increased emphasis on protecting low-voltage instrument systems from lightning discharges. These systems use direct-current voltages of 1 to 50 volts with 120 volt alternating-current power sources. This paper deals with methods used in a major oilfield automation project to protect various parts of the system from lightning damage. The lightning protection devices discussed are used to protect two computer-monitored oilfield automation projects located on the South high plains of West Texas near Levelland, Texas.