Session: 07-01-01 Liquids Release Consequence

Paper Number: 133491

133491 - A Spill Volume Calculation Approach and its Positive Impacts on Pipeline Risk Management 

Abstract: 

The loss of containment in liquid pipelines is a significant concern for pipeline operators, service providers, and regulators. Estimating the potential spillage volume at a designated pipeline location is critical for societal risk analysis, environmental impact assessment, and emergency response planning.

 

In the present methodology, the total spillage volume in each scenario consists of two parts: (a) the spill volume during operation while the pumps are active, and (b) the gravitational spillage volume after the pumps are shut down. A common industry practice to determine the operational spillage volume involves using commercial transient thermo-hydraulic simulation software. This software allows modeling the intended bore opening at a specified location and, through numerical simulation, defines the spillage volume within the time span required for the control room to detect the issue and respond by deactivating the pumps. Calculating this time span in advance for each scenario is essential.

 

In recent years, there has been a notable increase in the demand for spillage volume simulation in Brazil, propelled by the regulatory requirement for risk studies. This surge is particularly driven by the need for comprehensive environmental analyses related to pipeline water-crossings and quantitative risk assessments that consider the population residing in high-consequence areas. Brazilian environmental agencies now mandate the evaluation of three distinct pipeline failure scenarios: (i) a pinhole with a 5% bore opening, (ii) a hole with a 20% bore opening, and (iii) a rupture with a full-bore opening.

 

The increased demand has led to a significant rise in the utilization of numerical models and simulations. To meet this challenge, simplified hypotheses have been formulated. These hypotheses facilitate the computation of potential spillage volume during operation without relying on transient thermo-hydraulic software. Through the development and implementation of an algorithm, it becomes feasible to derive a comprehensive profile of the total spillage volume (both operational and gravitational) along the pipeline, based on the chosen discretization.

 

The innovative tool, MAVAZ, developed by SIMDUT/PUC-Rio and TRANSPETRO, has proven effective in meeting the requirements of Brazilian regulators. MAVAZ's calculation modules consider factors such as closure and containment times, offering a comprehensive approach to spill event analysis. The continuous development of MAVAZ calculation modules over the years has enhanced the realism of potential maximum leaked inventories, reducing the level of conservatism. Consequently, there have been positive impacts on cost optimization associated with pipeline risk management, both in risk analysis studies and in mitigating potential consequences through improved emergency response resources.

Presenting Author: Luis Fernando Pires Pontifical Catholic University of Rio de Janeiro

Presenting Author Biography: Luis holds a degree in Mechanical Engineering from the Federal Fluminense University (1980), a master's degree in Nuclear Engineering from the Military Institute of Engineering (1983), and a Ph.D. in Mechanical Engineering from the Pontifical Catholic University of Rio de Janeiro (1994). He also holds a postgraduate degree in Petroleum Engineering (2007). He was a professor at the Moacyr Sreder Bastos University Center until 2005, where he served as the coordinator of the Information Systems course. Retired as a Senior Researcher AIII from the Army Technological Center since 2013, he has been the General Manager since 2001 at the Thermo-Hydraulic Pipeline Simulation Center (SIMDUT/PUC-Rio).

He has expertise in the field of Mechanical Engineering, with a focus on Transport Phenomena and Numerical Methods, and he is currently conducting much of his research on the analysis of hydrocarbon transport in pipelines. His role at SIMDUT/PUC-Rio as a Project Manager includes the conceptual mechanical design of various gas pipelines, oil pipelines, ethanol pipelines, and distribution branch lines. He has been involved in the development of Operation Manuals for practically all oil pipelines operated by Transpetro and various gas pipelines. His work also involves calculating potential volumes leaked from oil pipelines and studying the expansion of oil pipelines. He has conducted capacity analyses of gas pipelines and evaluated changes in location class.

Authors:

Luis Fernando Pires Pontifical Catholic University of Rio de Janeiro
Claudio Barreto Pontifical Catholic University of Rio de Janeiro
Rodrigo Mesquita Pontifical Catholic University of Rio de Janeiro
Anderson Pacheco Petrobras Transporte S.A. – Transpetro
Ana Paula Bahiense Petrobras Transporte S.A. – Transpetro