Many miles of pipeline around the world are subject to damage from geohazards.  As used here, ‘geohazard’ refers to any earth movements sufficient to damage a pipeline, and can also include weather- and water-related events that are potentially damaging.  So, we often group, under the heading ‘geohazard’, a wide range of phenomena such as: landslide […]

Pipeline Risk Assessment

Risk assessment on any facility is most efficiently done by first dividing the facility into components with unchanging risk characteristics. For a cross-country pipeline, this involves collecting data on all portions of the pipeline and its surroundings and then using this data to ‘dynamically segment’ the pipeline into segments of varying length. Risk algorithms are […]

ILI vs DA—The Risk View

A rather common issue these days is decision making involving comparisons between In Line Inspection (ILI) vs Direct Assessment (DA, and, in particular, External Corrosion DA or ECDA).  You may need to research these techniques, if not already familiar to you, since we will assume the reader is fairly familiar with both. Both are acceptable […]

The Test of Time Estimation of Exposure

In the absence of more compelling evidence, an appropriate starting point for the exposure estimation may be the fact that a component or collection of components has not failed after x years in service. This involves the notion of having ‘withstood the test of time’. A component having survived a threat, especially for many years, […]

Damage vs failure: a risk assessment needs to know the difference

To measure resistance in a way most useful to a risk assessment, we must estimate the possible presence of weaknesses, the rate of emergence of future weaknesses, and the role of each weakness in strength reduction. By W. Kent Muhlbauer, WKM Consulting, Austin, TX, USA Since several of our recent columns have dealt with management-of-risk […]

Is this the same as SRA, LSD?

This recommended pipeline risk assessment methodology is similar to SRA (Structural Reliability Analyses) and LSD (Limit State Design) or LRFD (Load and Resistance Factor Design).  This is coincidental, since the methodology was developed independently from these techniques.  However, despite the similarities, there are key differences. Similarities include: Focus on engineering principles rather than incident history Accommodates […]

Pipeline Reliability–Service Interruption As ‘Failure’

Generally, a pipeline’s reliability includes consideration of all leak/rupture scenarios PLUS all other scenarios that could prevent the system from performing its intended function.  With the normal ‘intended function’ being something like:  deliver product to point B from point A at specified flow rates, pressures, temperatures, and product quality, a reliability failure occurs when any […]

Monetized Risk

Quantifying potential consequences with a common scale can be challenging. Using a measure such as cost—the monetized loss associated with the damages—forces some difficult judgments to be made among various receptor damages. For example, not only must a value be assigned to a statistical human life, but also to various injury types, environmental damage, damage […]