Sub-soil contamination due to oil spills in zones surrounding oil pipeline-pump stations and oil pipeline right-of-ways in Southwest-Mexico

Oil spills due to oil pipelines is a very frequent problem in Mexico. Petroleos Mexicanos (PEMEX), very concerned with the environmental agenda, has been developing inspection and correction plans for zones around oil pipelines pumping stations and pipeline right-of-way. These stations are located at regular intervals of kilometres along the pipelines. In this study, two sections of an oil pipeline and two pipeline pumping stations zones are characterized in terms of the presence of Total Petroleum Hydrocarbons (TPHs) and Polycyclic Aromatic Hydrocarbons (PAHs). The study comprehends sampling of the areas, delimitation of contamination in the vertical and horizontal extension, analysis of the sampled soils regarding TPHs content and, in some cases, the 16 PAHs considered as priority by USEPA, calculation of areas and volumes contaminated (according to Mexican legislation, specifically NOM-EM-138-ECOL-2002) and, finally, a proposal for the best remediation techniques suitable for the contamination levels and the localization of contaminants.     

Airbag for the closing of pipelines on explosions and leakages

This paper is a result of international effort aimed at the construction of a device for quick closing of pipelines in the case of explosion propagation and/or chemical leakage. Such a problem exists in industries where flammable substances are transported by pipelines. The basic solution principle was the idea to use airbags similar to those utilized in cars.

Two pipeline applications were taken into consideration: a low-pressure module able to suppress explosion propagation and a high-pressure module to stop leakages from, e.g. natural gas pipeline capable to be used for duct diameters up to 0.6 m, pressures up to 5 MPa and reaction times of 50 ms. It was necessary to construct a new airbag, capable of withstanding up to 10 bar pressure. The choice of material was critical to ensure sufficient strength and chemical resistance while retaining impermeability.

CFD modeling of the bag deployment into a pipe flow and analysis of the bag shapes was also completed. Two gas generators were constructed and tested with novel propellant materials.

Different airbag models were tested to evaluate their effectiveness. Risk analysis approach was applied to evaluate the safety and economic benefits of the new technology in different fields of application.     

Identification of environmentally vulnerable areas with priority for prevention and management of pipeline crude oil spills

The oil industry is one of the main productive activities in Mexico and has a huge infrastructure, including a wide pipeline network that crosses urban, industrial, agricultural and natural areas. The threat of crude oil spills is greatest in those regions with a high concentration of oil extraction and refining activities, as in the case of the Coatzacoalcos and Tonalá Rivers Low Basin. This study ranked the geosystems of the basin in terms of vulnerability to pipeline crude oil spills. Very high vulnerability (level I) was assigned to the water bodies (lakes and rivers) and their margins of influence, including surfaces that flood during normal hydraulic load. High vulnerability areas (level II) comprised surfaces that can flood during extraordinary hydraulic load related with extreme hydrometeorological events. The remaining three vulnerability levels were defined for areas with low or negligible flooding potential, these were ranked according to physical (slope, relief and permeability), biological (richness, singularity and integrity) and socio-economic (social marginalization index and economic activities index) conditions. These results are presented on a map for better visualization and interpretation. This study will be useful to establish preventive and effective emergency management actions in order to reduce remediation costs and adverse effects on wild species. It also can help local and national authorities, oil industry and civil protection corps to better protect ecosystems, natural resources and human activities and goods.     

Fault diagnosis of pipeline and pump unit systems using status coupling analysis

Earlier studies on fault diagnosis of the pipeline and pump unit systems (PPU) relied mainly on independent equipment analyses, which usually lead to false alarms because of the loss of information fusion. The aim of this study is to utilize the status coupling relationship to improve fault detection sensitivity and reduce false alarm rate. A real-time status identification of related equipment step is added between capturing abnormal signals and listing out diagnosis results. For example, when the pipeline pressure fluctuation is found abnormal, a status analysis of pump units is performed immediately, if the pump units are proven to be operational normally, then the pipeline leak alarm is acknowledged valid. The logical reasoning algorithm is used to capture abnormal conditions of pipeline pressures. The pump unit faults are captured by combining information from multiple sources. Field applications show that the proposed method significantly improves the PPU fault detection capability on fault detection sensitive and accuracy.     

Risk assessment methodology for high-pressure CO2 pipelines incorporating topography

This paper presents a risk assessment methodology for high-pressure CO₂ pipelines developed at the Health and Safety Laboratory as part of the EU FP7 project CO2Pipehaz.Traditionally, consequence modelling of dense gas releases from pipelines at major hazard impact levels is performed using integral models with limited or no consideration being given to weather bias or topographical features of the surrounding terrain. Whilst dispersion modelling of CO₂ releases from pipelines using three-dimensional CFD models may provide higher levels of confidence in the predicted behaviour of the cloud, the use of such models is resource-intensive and usually impracticable. An alternative is to use more computationally efficient shallow layer or Lagrangian dispersion models that are able to account for the effects of topography whilst generating results within a reasonably short time frame.In the present work, the proposed risk assessment methodology for CO₂ pipelines is demonstrated using a shallow-layer dispersion model to generate contours from a sequence of release points along the pipeline. The simulations use realistic terrain taken from UK topographical data. Individual and societal risk levels in the vicinity of the pipeline are calculated using the Health and Safety Laboratory's risk assessment tool QuickRisk.Currently, the source term for a CO₂ release is not well understood because of its complex thermodynamic properties and its tendency to form solid particles under specific pressure and temperature conditions. This is a key knowledge gap and any subsequent dispersion modelling, particularly when including topography, may be affected by the accuracy of the source term.     

Mitigating the consequences of extreme events on strategic facilities: evaluation of volcanic and seismic risk affecting the Caspian oil and gas pipelines in the Republic of Georgia

In this work we identify and quantify new seismic and volcanic risks threatening the strategic Caspian oil and gas pipelines through the Republic of Georgia, in the vicinity of the recent Abuli Samsari Volcanic Ridge, and evaluate risk reduction measures, mitigation measures, and monitoring. As regards seismic risk, we identified a major, NW-SE trending strike-slip fault; based on the analysis of fault planes along this major transcurrent structure, an about N-S trend of the maximum, horizontal compressive stress (σ1) was determined, which is in good agreement with data instrumentally derived after the 1986, M 5.6 Paravani earthquake and its aftershock. Particularly notable is the strong alignment of volcanic vents along an about N-S trend that suggests a magma rising controlled by the about N-S-directed σ1. The original pipeline design included mitigation measures for seismic risk and other geohazards, including burial of the pipeline for its entire length, increased wall thickness, block valve spacing near recognized hazards, and monitoring of known landslide hazards. However, the design did not consider volcanic risk or the specific seismic hazards revealed by this study. The result of our analysis is that the Baku-Tbilisi-Ceyhan (BTC) oil pipeline, as well as the Baku-Tbilisi-Erzerum South Caucasian natural gas pipeline (SCP) were designed in such a way that they significantly reduce the risk posed by the newly-identified geohazards in the vicinity of the Abuli-Samsari Ridge. No new measures are recommended for the pipeline itself as a result of this study. However, since the consequences of long-term shut-down would be very damaging to the economies of Western Europe, we conclude that the regionally significant BTC and SCP warrant greater protections, described in the final section of or work. The overall objective of our effort is to present the results in a matrix framework that allows the technical information to be used further in the decision-making process, with the goal of reducing the uncertainty in the final decision. This approach is applicable to the study of risks in other pipeline systems.     

Towards more detailed determination of third party impact on risk on natural gas pipelines: Influence of population density

The paper presents a refined way to quantify the effects of third party interference on risk that is posed on people by transmission pipelines for natural gas. The main focus is set on the influence of population density on risk. Using the interdisciplinary approach, the presented study combines the knowledge from relevant risk assessment recommendations, physical consequences of hazardous events, existing history databases of hazardous event frequencies and urban planning. A quantitative boundary between two most populated types of area was established. A flexible risk coefficient was determined for a suburban type of populated area that is dependent on average population density. Consequently, a new approach for determination of a hazard distance from the pipeline and area boundaries for calculation of average population density was presented. This differs from the established methods described in some guidelines, but is based on results of applied quantitative risk assessment. The final result is more accurate determination of risk levels in suburban areas. Described methods may serve as a supplement to the existing models for quantitative risk assessment on pipelines used in natural gas transportation and may be used by pipeline operators as well as policy- and decision makers.     

辐射固化纳米环氧酚醛涂层的特点

辐射固化纳米环氧酚醛涂层在耐腐蚀、抗渗透、防结垢、防结蜡、耐磨损、抗细菌腐蚀、耐热性及绝热性等方面均有着突出的表现,在提高生产效率、节能降耗、安全环保等方面也有着积极的作用.这些突出的综合性将能够有效应对近年来的高温、高压、高含硫气田中频繁发生的集输管道腐蚀失效问题.在不久的将来,该类涂层可能会是石油化工管道功能性涂层中最好的选择之一.     

Plant response to utility right of way construction in the Mojave Desert

Disturbance of flora from utility construction tends to generate new plant growth. This growth changes productivity, diversity, and stability. Although the enhancement of vegetation may balance out the biomass destroyed by the original disturbance, it often adversely affects the quality of the vegetation. Percentage composition of the dominant long-lived perennials combined with quantitative measures are used to assess longterm effects of utility corridor construction. Differential effects of enhancement of vegetation are found along road edges, enhancement under wires of powerlines, and over trenches dug for pipelines. Areas under powerline pylons seem to receive the greatest damage and also show the most variable recovery of vegetation. Significant recovery rates are noticeable where the time span between year of construction has allowed for considerable regrowth of the older corridor. Recovery rates depend on soil type, landform, and other physical features of the disturbed sites. Drastic disturbance in one area or transect site may impede vegetation recovery, whereas slight disturbance might enhance vegetation in another, tending to offset the effect of the drastic disturbance. Disturbed areas and control areas may appear to have similar vegetation covers, biomasses, and densities, but these similarities often vanish when one examines qualitative aspects, such as proportion of long-lived species and presence of characteristic dominants.     

Seismic vulnerability of gas and liquid buried pipelines

Lifelines play a crucial and essential role in human life and in economic development. The resilience of those systems under extreme events as earthquakes is a primary requirement, especially when large amount of toxic and flammable material are transported.In this work, the seismic vulnerability of buried gas and liquid pipelines has been analyzed, starting from a large number of damage data to pipelines collected from post-earthquake reconnaissance reports.Seismic fragility formulations and threshold values for the earthquake intensity with respect to the release of content from different types of pipelines have been derived. The main outcome of the work is therefore a novel seismic assessment tool which is able to cover the needs of industrial risk assessment procedures and land use planning requirements.