H2S Early Notification System for Production Pipelines: A Pilot Test
George J. Hirezi, Faisal T. Al-Khelaiwi, Mohammed N. Al-Khamis · 2012
Abstract The produced fluid of an oil field located in the Eastern Province of Saudi Arabia contains relatively high levels of H2S. A pilot test was conducted by Saudi Aramco to install a wireless gas detection system along an oil pipeline in this field. The pilot test objectives include: Determining the communication availability and reliability of the remote wireless sensors where extending hardwired and fiber optic networks proved impractical and expensive. Evaluating the usefulness of this system for early notification of toxic gas releases or pipe leaks in and around critical geographical areas by alerting the console operator and via e-mail and Short Message Service (SMS). The piloted system includes six wireless sensors separated at an equal distance along a 2 km oil pipeline. The sensors communicate wirelessly with a gateway receiver located in a shelter at a producer site. The wireless gateway is integrated with an existing Supervisory Control and Data Acquisition (SCADA) system by connecting it serially to a Remote Terminal Unit (RTU). Accordingly, the sensor's measurement and diagnostic data is monitored by the operators at their console in the control room. The same data is also accessible to the engineers at their desktops for real time monitoring and long-term archiving purposes via the OSI PI system. The test results of the year-long pilot indicated that the gateway receiver demonstrated very high reliability and availability since it had no failures during the test period; however, initially some of the wireless sensors had experienced minor but recoverable communication errors. This paper describes the details of this pilot test and discusses the difficulties encountered during the project's testing phase along with the actions taken to mitigate such problems, and subsequently improve the overall reliability and availability of the wireless communication.