Systematic Approach Devised To Enhance Inspection/Maintenance Communications And Performance

The quantity of equipment associated with upstream natural gas or oil gathering networks represents an inspection and maintenance challenge equivalent to a moderately sized refinery, but complicated by being dispersed over a large geographic area. A gas or oil gathering system consisting of a thousand well sites would be expected to include about 50 small processing and transmission facilities, up to a thousand pipeline segments and one or more large processing facilities or terminals.

This has the potential to make the difficult task of effectively communicating among the inspection, maintenance and engineering departments even more daunting. A systematic approach to managing the inspection findings and their remediation can significantly improve the overall effectiveness of the entire mechanical integrity program.

The problem with traditional methodologies. The traditional method of inspection and remediation relies on expert inspectors collecting reproducible quantitative data and well-described qualitative observations. These findings are then prioritized and remediated according to corporate maintenance and engineering standards. In practice, there are several factors which complicate the process. One of the most significant factors is that there is an increasingly declining number of senior experienced inspection, maintenance and engineering personnel as a result of a high percentage of these specialists reaching retirement. The retirement of these subject matter experts represents a significant potential for losing corporate knowledge, expertise and intellectual property.

Another factor affecting the process of inspection and remediation is the tendency of each inspector to describe his or her observations uniquely. Figure 1 illustrates the issue. If there were 50 experienced inspectors (e.g., API-510, API-570 and API-653 inspectors) observing and reporting a deficiency the result would most likely be 50 different - although accurate - descriptions of the findings. Because each inspector’s finding is unique, the recommendations for remediation must be custom-generated by knowledgeable personnel. This makes it difficult to establish, transmit and enforce corporate engineering and maintenance standards for remediation.

A third factor affecting the process is the substantial time delay between the inspection and the generation of a prioritized work list that can be used by maintenance to remediate the deficiencies. Delays of three to four months between the time of inspection and the generation of actionable reports are common. Unfortunately, this can sometimes result in loss of containment before the maintenance department is aware of a problem.

The right side of Figure 2 shows the traditional approach to processing inspection findings. The process starts when the certified inspector visits the field to conduct the inspection. The inspection generates a set of numerical data and a set of visual observations which are uniquely described. Typically, this data will be written onto isometric drawings of the equipment. The numerical data must be analyzed to determine corrosion rates and remaining lives. Equipment items requiring retirement or with limited remaining life are given high priorities for remediation. Each visual observation is prioritized by a knowledgeable inspector or engineer who then generates a custom recommendation to remediate the deficiency. This information may be entered into a mechanical integrity database by a data analyst.