Identification of the most potentially hazardous systems for risk analysis

Identification of the Most Potentially Hazardous Systems for Risk Analysis

At present, the role of risks in production facilities, hazardous industrial facilities, and in the global and Russian economy as a whole has grown to such an extent that we have come to define risks as one of the foundations of the modern approach to industrial safety analysis at facilities. Accordingly, when implementing industrial projects, they cannot be ignored, as this can negatively affect the efficiency of project activities, construction, and operation as a whole. This primarily concerns large oil and gas industry projects.

Here we will examine what constitutes a brief overview of the main concepts of the traditional approach to risk analysis, which includes an algorithm for conducting analysis:

• Definition of systems for analysis;
• Hazard identification;
• Probability assessment;
• Consequence analysis;
• Risk analysis results;
• Development of recommendations for risk reduction.

The foundation of the traditional approach to risk analysis is the assessment of various scenarios that may lead to undesirable outcomes. Both the probability and scale of such outcomes are evaluated and presented as results.

In the process of performing risk analysis, a development scenario represents a chain of events that may lead to an undesirable outcome. Here is the sequence of events in a typical scenario analysis:

1. Loss of containment;
2. Detection;
3. Isolation;
4. Impact mitigation

Depending on the nature of the process and study characteristics, risk analysis may include thousands of different scenarios similar to the one presented above. Risk analysis evaluates both the probability and consequences of the chain of events occurring in each scenario. Probability and consequences are also assessed, but only for carefully defined and limited numbers of scenarios.

Definition of Main Systems for Risk Analysis

At the system definition stage, analysis is conducted during which basic rules are established and all essential information is gathered.

The basic rules of analysis are:

1. Goals and objectives are established for effective motivation when conducting risk analysis. The following goals may be set: compliance with established regulatory requirements, conducting analysis of production costs or revenues from it, evaluation of a proposed project to increase capacity, etc.
2. The need to measure the degree of risk is required to clarify the final results necessary to achieve the set goal. System areas – definition of physical and operational limits of the system. Physical areas define the set of equipment included in the study. Operational areas include functions or operating modes of the system.
3. Level of detail – definition of the procedure for analyzing installations within the system. Such questions as "Will each pipe section be modeled?" or "Will pipelines be grouped together for simpler analysis?" should be resolved at an early stage of program implementation.
4. Data collection – definition of information to be collected and updated. The most recent drawings and process flow diagrams are selected. Other relevant information, including weather or population information, may also be collected depending on study objectives. If, for example, the study relates only to fire risks, and the nearest housing is more than a mile away, there is no need to collect detailed population information. An example of typical information collected for such risk analysis is provided below.

Basic Data Collected for Risk Analysis

Hazard source information:

• Material data
• Existing hazard and operability study results
• Location of ignition sources (process flow diagrams)

Design data and operational characteristics:

• Process equipment dimensions (vessels, columns, tanks, etc.)
• Pipeline diameters and lengths
• Equipment operating conditions
• Pump and compressor capacity
• Design characteristics
• Technological processes

Support systems:

• Gas detection
• Flame and fire detection
• Toxic substance detection, etc.

Environmental data:

• Average wind speeds
• Maximum five-day temperature
• Probable wind directions (wind rose), etc.

Fire protection systems:

• Control procedures
• Fire suppressing agents
• Agent flow rates

Historical data:

• Commissioning data
• Industrial injury statistics
• Worker schedules (day-night), etc.

External data:

• Number of people living outside the work area
• Land information within 1-5 km
• Terrain topography, etc.

Risk identification and assessment procedures (HAZID, HAZOP) are covered in the article "HAZOP Methodology".