Performance Requirements Demand Careful Safety System Selection

Asset and system availability, along with process uptime, are more critical than ever in the oil and gas industry. At today’s high fuel prices, each minute of uptime counts. Any disruption of the supply chain creates a strain in the market and puts companies at risk of incurring substantial downtime losses.

While safety is a concern across all manufacturing sectors, it is especially critical in the oil and gas industry. The risks can be far reaching. The inability to respond effectively to hazardous situations can be costly, from jeopardizing personnel to diminishing the bottom line, brand reputation or consumer and investor confidence.

Role of the Safety System

Oil and gas companies employ a variety of processes that, for practical and financial reasons, require continuous operation. For example, a shutdown of a fuel distribution pipeline may take days to restart and cost millions in lost production. Therefore, it is essential that critical devices—such as pumps, compressors, motors and instrumentation—continue working if the primary control system fails.

In most production operations, the basic process control system (BPCS) —historically a DCS, but increasingly a programmable automation controller (PAC)-based system—continuously monitors the process and controls parameters—including temperature, flow, pressure, weight and viscosity. The BPCS maintains the process variables within safe boundaries and, therefore, can help provide some level of protection. Specifically, the control system detects a change in flow or pressure and responds.

However, processes have the potential to create hazardous situations when the BPCS is out of control or unexpectedly fails. This is where the safety instrumented system (SIS) comes into play. The goal of the SIS is to maintain the safety of a facility in the event of a control system failure. This may require an orderly shutdown of the process to help protect people, the equipment and production.

Match the Technology to the Application Demands

Selecting the right technology requires in-depth analysis. Just as each project is different, so are safety system needs. A detailed, systematic, methodical, well-documented process is necessary in the design of safety instrumented systems.