Quantitative Risk Assessment Of buried crude Oil Pipelines

Currently, I am working on a project that necessitates a quantitative risk assessment (frequency analysis and consequence analysis) of buried crude oil pipelines, considering specific hazard scenarios.

Most of the hazard analyses I have come across were conducted on gas pipelines, and there seems to be a limited number of publications that deal with liquids. Moreover, these few studies do not consider crater formation. I have found that the PHAST software considers crater formation, but as a student, the subscription cost is expensive for me.

I was wondering if anyone could recommend any resources or literature that specifically address crater formation in the context of pipeline hazards involving crude oil.

Also, I have been reviewing several research papers and noticed that many of them use databases of historical accidents for their assessments.
Provided the pipeline system requires relevant information regarding the pipeline design and installation, properties of the fluid being transported, and the main conditions in the surroundingsWhile I understand the value of this approach, I have some concerns about its applicability to my study. Specifically, I am unsure how accidents involving pipelines with different pipeline systems are relevant to the parameters I will choose for my study.I am unsure how to draw conclusions from this historical data given these differences.

In many parts of the US, counties will do multi-risk assessments as part of qualifying for government grants for infrastructure improvements. I don't know if you have the same requirements in your area where you are doing this risk assessment, but if you do, check the county records to see if they have one available to the public that includes a section on the oil pipeline that passes through that county.

I was on committee here locally in Alameda County (in Northern California) a few years ago, and the amount and quality of the work that went into that risk assessment study was amazing. I don't think our full report was available to the public in the end (particularly the sections on terrorism), but hopefully you can find something.

I tried searching for risk assessments on the US Department of Transportation site, and I found a document on how to perform pipeline risk modeling. I will definitely use it in my report. However, I forgot to clarify that I am using data from a paper that developed a methodology for performing Quantitative Risk Assessment (QRA) for onshore crude oil pipelines in Colombia.

I am having a lot of issues understanding their approach. The reason I am using this paper is that it contains information about the pipeline system, including pipeline design, fluid properties, and operating conditions. However, the Colombian pipeline failure incident reports lack data on the size of the failures. As a result, the paper used data from the report "performance of European cross-country oil pipelines."

The report reported spillage distributions by hole size range, referring to them as no hole, ,split, pinholes, fissures, and ruptures. In the paper, they considered four different failure sizes from each range and assigned them the same frequency as reported in the report. I'm wondering why they didn't consider all pipeline failure sizes, where the equivalent hole size diameter falls between 0 and the pipeline diameter. What if pipeline failures occur at different sizes than the ones considered in the paper? Is it appropriate to use data from database on pipeline failures with a different pipeline system?

In my judgment, the first step is to identify the failure mechanism (or mechanisms). It is important to then articulate the physical process for failure on a fundamental basis, and derive the equations for the process to occur, at least leading up to the critical loading. Sometimes, if data is available, dimensional analysis can be used. Identification of the key dimensionless groups can reduce the number of independent physical parameters involved, and can help map out the regions to be avoided.

Chestermiller said:

In my judgment, the first step is to identify the failure mechanism (or mechanisms). It is important to then articulate the physical process for failure on a fundamental basis, and derive the equations for the process to occur, at least leading up to the critical loading. Sometimes, if data is available, dimensional analysis can be used. Identification of the key dimensionless groups can reduce the number of independent physical parameters involved, and can help map out the regions to be avoided.

After researching for the past few days, I found that internal corrosion is one of the leading types of pipeline failure. I read that crude oil is not corrosive by itself, but crude oil contains water and sediments limited to <0.5 % wt, and the solid particles tend to be encapsulated by a layer of water that may concentrate water on the pipe wall surface. This creates the potential for corrosion to occur if the flow conditions of the pipeline system allow for these solids to settle out. The primary factor that affects internal corrosion in transmission pipelines is flow rate (low velocities). I was thinking of developing a CFD model of the two-phase flow to determine the velocity profile and identify locations where the velocity is lower than the entertainment velocity (the velocity at which water settles out from the crude oil). These locations are highly susceptible to corrosion. However, I am not sure if this approach is correct.

Considering the long history of oil pipelines, it occurs to me that there is probably much history, and predictions, about corrosion.

https://www.google.com/search?hl=en&q=high+corrosion+areas+in+crude+oil+pipelines

I stopped counting pages when I got to pg. 11.

Cheers,
Tom