Application and Performance Monitoring of Compound Air Plasma Lightning Rejection System

Abstract

The objective of this paper is to share on the application and performance monitoring of Compound Air Plasma Lightning Rejection (CPLR) system at an onshore terminal facility. Malaysia is one of the top three countries in the world with high lightning density, recorded average of 13.9 flashes per square kilometer annually. Thus, the country's oil and gas industry is indeed vulnerable to the dangerous impact of lightning, often associated with risk like fire, explosion, and release of hazardous material. During the initial stage of lightning development, the air acts as an insulator between positive and negative charges at the cloud and ground. However, when the difference between charges is too great, the insulating capacity of the air breaks down, caused rapid discharge of electricity and resulting in a lightning formation. Upon detection of potential difference between storm cloud and ground, CPLR will release plasma ion, that in theory will neutralize the positive and negative ions and eventually prevent lightning to happen. This paper will discuss on the investigation outcome of two vent fire incidents at the produced water tanks of an oil and gas receiving facility at east coast of Malaysia, in relation with the functionality of this novel active lightning protection system. Detailed comparison has been made between CPLR lightning rejection data and the data from an electricity utility research company (TNB-Research) lightning mapping to study the system's reliability and effectiveness. During the first vent fire incident in 2018, data analysis showed that there was no lightning strike within the CPLR coverage area and suspected the lightning propagated from the nearest striking point in lightning mapping following the path of least resistance. In addition, this also surfaced up several installation issues such as insufficient protection coverage due to incorrect pole height design, communication card failure etc. Identified action items have been implemented to restore the CPLR system for tank lightning protection. After that, the system has been closely monitored for its performance and it showed reliable lightning rejection data in year 2020 with no vent fire occurence. However, the second vent fire incident happened in 2021. Post investigation, TNB-R data showed that the lightning stroke 200m from the produced water tank recorded peak current value at −68kA which was two times higher than the average lightning amperage. This concluded that CPLR was unable to reject propagated lightning of high magnitude as well. In overall, CPLR system is proved to be functioning but with limitation in terms of coverage area and lightning magnitude (kA). With this paper presented, it is expected to complement this novel technology literature with its proof of function, field site installation precautions and as-found system limitations.