Petroleum Facilities Research Articles

Development of Process Safety Cumulative Risk Assessment and Visualization Model/Framework for Petroleum Facilities in Niger-Delta Region, Nigeria

One of the key challenges in preventing major process safety accidents in an operating plant is the lack of an integrated system/model that brings together the risks posed by the deficiencies / deviations on the safety critical barriers, for operational decision making. Based on this context, an exploratory study was undertaken to develop a model/framework for visualizing the accumulation of process safety risks arising from safety critical barriers impairments in petroleum facilities in Niger-Delta Nigeria. A “focused group” was used to test/validate the model/framework using two case studies. The results indicate that the process safety cumulative risk assessment framework/model offers a transparent mechanism for assessing and visualizing the cumulative risks arising from the barrier impairment problems. For the facility in the first case study, 3.2% of the total number of safety-critical barriers was deviated and the model revealed risk accumulation in the gas compression functional location. For the facility in the second case study, 1.7% of the total number of safety-critical barriers was deviated and the model revealed risk accumulation in the gas dehydration functional location. When applied properly, the model/framework will reduce the risk of major accident in petroleum facilities by (a) aiding better management of safety critical barriers deviations through improved risks visual and (b) eliminate variability in human interpretation of process safety risk levels. One improvement area identified in the model/framework is the need for a web-based software for automation of barrier impairment data collection and real-time visualization of the cumulative risk picture.

Development of Process Safety Cumulative Risk Assessment in Niger-Delta Region, Nigeria

One of the key challenges in preventing major process safety accidents in an operating plant is the lack of an integrated system/model that brings together the risks posed by the deficiencies / deviations on the safety critical barriers, for operational decision making. Based on this context, an exploratory study was undertaken to develop a model/framework for visualizing the accumulation of process safety risks arising from safety critical barriers impairments in petroleum facilities in Niger-Delta Nigeria. The results indicate that the process safety cumulative risk assessment framework/model offers a transparent mechanism for assessing and visualizing the cumulative risks arising from the barrier impairment problems. For the facility in the first case study, 3.2% of the total number of safety-critical barriers was deviated and the model revealed risk accumulation in the gas compression functional location. For the facility in the second case study, 1.7% of the total number of safety-critical barriers was deviated and the model revealed risk accumulation in the gas dehydration functional location. When applied properly, the model/framework will reduce the risk of major accident in petroleum facilities by (a) aiding better management of safety critical barriers deviations through improved risks visual and (b) eliminate variability in human interpretation of process safety risk levels. One improvement area identified in the model/framework is the need for a web-based software for automation of barrier impairment data collection and real-time visualization of the cumulative risk picture.

Artificial Intelligence (AI) Application in Process Safety Cumulative Risk Visualization for Petroleum Operations: Conceptual Framework

One of the key challenges in preventing major process safety accidents in an operating plant is the lack of an integrated system/model that brings together the risks posed by the deficiencies / deviations on the safety critical barriers, for operational decision making. Based on this context, a model/framework was developed for assessing and visualizing the accumulation of process safety risks arising from safety critical barriers impairments in petroleum facilities in Niger-Delta Nigeria. Based on the review of the model, the need for an intelligent web-based software was identified. An exploratory study was therefore undertaken through extensive literature review and focused group participants, to develop a conceptual framework for an intelligent web-based software for process safety cumulative risk visualization. The results from the study make it evident that the conceptual framework provides a novel approach in developing an intelligent web-based software using artificial intelligence (AI) techniques, for real time visualization of process safety cumulative risk picture.

EVALUATION OF CATHODIC PROTECTION SYSTEM FOR PIPELINES AT BREGA PETROLEUM MARKETING COMPANY IN LIBYA

Cathodic protection (CP) is the most effective method for protecting petroleum facilities against corrosion. As part of this protection, care should be taken to continuously evaluate the existing system in order to maintain the system in favorable conditions. The subject of the paper’s research is an oil plant for the transportation of oil derivatives located at the Brega company in Tobruk, Libya. In the present work, a case study on how to evaluate the CP system for an existing company for petroleum transportation is considered. The procedure was planned in three steps. The first step is a historical survey of the CP system from when the company started. The second was a diagnostic analysis study of the problem and how to fix it along the system. The third is the conclusions and recommendations regarding the measures for evaluating the CP system without stopping production.

Physical Work Demands of Maintenance Workers on Onshore Petroleum Facilities in Norway: An Observational Study Utilizing Wearable Sensor Technology.

High physical work demands can cause musculoskeletal disorders and sick leave in petroleum workers. However, our knowledge of their physical work demands is scarce and based on self-report. The objective of our study is to work towards closing this knowledge gap by assessing the physical work demands of onshore petroleum maintenance workers using body-worn sensors. A total of 46 of 69 eligible maintenance workers (37 mechanics and 9 process technicians) from three onshore petroleum facilities in Norway filled in a questionnaire and diary and wore five accelerometers and a heart rate sensor for up to six consecutive workdays. Work-related physical activity and postures were classified using rule-based modelling in a modified version of the validated Acti4 software. The onshore maintenance petroleum workers were working an average of 10 h a day and spent on average this time with 48% (SD = 16.5) sitting, 1% (SD = 2.8) lying down, 39% (SD = 16.2) in light physical activity, and 9% (SD = 3.8) in moderate to vigorous physical activity. During work hours while at feet, we found arm elevation ≥60° to be 11% (SD = 7.1) (68 min), and forward bending of the trunk ≥60° to be 2% (SD = 2.2) (14 min). The workers spent 2% (SD = 2.5) (12 minu) of the workhours kneeling. We observed a high inter-individual variation for all these work exposures. Moreover, 26% (12) of the workers conducted static standing for >30% of the workday, and 17% (8) spent more than half of the work hours >33% of their estimated maximal cardiovascular capacity. While onshore maintenance petroleum workers on average spend about half of the workday sitting or lying down, the remaining worktime is spent with a rather high duration of arm elevation and forward bending. Quite high fraction of the workers spends much of the workhours in static standing and kneeling. We see a substantial variation in these work exposures between the workers. The findings indicate a need for preventive measures in how work is organized and performed.

Computational fluid dynamics approach to study methane hydrate formation in stirred reactor

Hydrate formation management in oil and gas industries needs a detailed understanding of hydrate formation phenomena in terms of dynamics and kinetics aspects. Stirred reactors are one of the popular experimental systems to study hydrate formation/dissociation in terms of kinetics and thermodynamics mechanisms. Various processes/systems such as gas hydrate formation and decomposition phenomena in oil and gas facilities are simulated using computational fluid dynamics (CFD). This research examines the hydrate formation in a stirred reactor for a water-methane system using the Eulerian multiphase flow model by employing CFD software (STAR CCM +). The developed numerical model incorporates the conservation equations of momentum, mass, and energy, where the hydrate equations, including mass transfer, hydrate kinetics, and heat of hydrate formation, are included in the governing equations. In this paper, the methane hydrate formation in the stirred reactor for the stirring rate of 300 RPM and volume fraction of 0.04 with a pressure of 5,500 kPa is simulated. Then, the simulation results are validated using the experimental data collected from the literature, resulting in an overall absolute average deviation percentage (AAD%) of 15.6 %. The influences of stirring rate (300 to 500 RPM), methane volume fraction (0.04 to 0.4), pressure (3,500 to 7,500 kPa), and subcooling (1.96 to 9.23 °C) are studied on the hydrate formation in the agitated reactor. The results reveal that the developed CFD model can predict the methane hydrate formation in the stirred reactor with acceptable precision. According to the simulation runs, methane hydrate is formed mainly near the walls and around the stirrer blades. In addition, an increase in subcooling, gas volume fraction, pressure, and stirring rate leads to more hydrate formation in the reactor with a constant temperature of 274.3 K. The maximum mass fraction of hydrate is observed for the case when the gas volume fraction and stirring rates are 0.4 and 900 RPM, respectively. However, the minimum value of methane hydrate is 0.092 g, where the volume fraction and impeller speed are 0.04 and 300 RPM.The findings of this study can help to further understand hydrate formation phenomena in oil and gas facilities. This model can provide oil and gas engineering sectors with effective strategies to control and manage gas hydrates. In addition, the proposed CFD model can be helpful for engineers and researchers in the petroleum industry to simulate hydrate formation in other complicated geometries in petroleum facilities.

Modelling the relationships between the barriers to implementing machine learning for accident analysis: the Indian petroleum industry

PurposeThis paper aims to identify, prioritise and explore the relationships between the various barriers that are hindering the machine learning (ML) adaptation for analysing accident data information in the Indian petroleum industry.Design/methodology/approachThe preferred reporting items for systematic reviews and meta-analysis (PRISMA) is initially used to identify key barriers as reported in extant literature. The decision-making trial and evaluation laboratory (DEMATEL) technique is then used to discover the interrelationships between the barriers, which are then prioritised, based on three criteria (time, cost and relative importance) using complex proportional assessment (COPRAS) and multi-objective optimisation method by ratio analysis (MOORA). The Delphi method is used to obtain and analyse data from 10 petroleum experts who work at various petroleum facilities in India.FindingsThe findings provide practical insights for management and accident data analysts to use ML techniques when analysing large amounts of data. The analysis of barriers will help organisations focus resources on the most significant obstacles to overcome barriers to adopt ML as the primary tool for accident data analysis, which can save time, money and enable the exploration of valuable insights from the data.Originality/valueThis is the first study to use a hybrid three-phase methodology and consult with domain experts in the petroleum industry to rank and analyse the relationship between these barriers.

Modeling and Controller Design for Temperature Control of Heat Exchangers in Power Plants

A heat exchanger is a device that transfers heat from one place to another. Because it can withstand a wide range of temperature and pressure, the power plant heat exchanger is widely employed in chemical and petroleum facilities. A heat exchanger is a device that transfers heat from one place to another. Plant with strong nonlinearity and low dynamics; as a result it is tough to model and manage its dynamics. There are two types of heat exchanger models in this study. For selecting an appropriate model, controllers are used. Controller. (Physical model) is the first model. Generated from genuine heat exchanger plant parameters Second, there's Dead Time plus a Second Order (SOPDT model)This is obtained from the heat exchanger's response. While The controllers are made up of fuzzy proportional controllers. Proportional integral (FPD) controller and derivative (FPD) controller applied to the model as a derivative (PID) controller Their comments are compared to those of the others. Keywords Power Plant Heat Exchanger, Modelling, Fuzzy Control.

Combined stochastic and discrete simulation to optimise the economics of mixed single-horizontal and multilateral well offshore oil developments

Multilateral wells promise cost savings to oil and fields as they have the potential to reduce overall drilling distances and minimize the number of slots required for the surface facility managing the well. However, drilling a multilateral well does not always increase the flow rate when compared to two single-horizontal wells due to competition in production inside the mother-bore. Here, a holistic approach is proposed to find the optimum balance between single and multilateral wells in an offshore oil development. In so doing, the integrated approach finds the highest Net Present Value (NPV) configuration of the field considering drilling, subsurface, production and financial analysis. The model employs stochastic perturbation and Markov Chain Monte-Carlo methods to solve the global maximising-NPV problem. In addition, a combination of Mixed-Integer Linear Programming (MILP), an improved Dijkstra algorithm and a Levenberg-Marquardt optimiser is proposed to solve the rate allocation problem. With the outcome from this analysis, the model suggests the optimum development including number of multilateral and single horizontal wells that would result in the highest NPV. The results demonstrate the potential for modelling to find the optimal use of petroleum facilities and to assist with planning and decision making.

A comprehensive numerical design of firefighting systems for onshore petroleum installations.

Petroleum facilities containing welded steel bulk flammable liquid product storage tanks possess sundry fire hazards inherent to the facility. These installations urgently require indigenous efficient firefighting systems. So, the efficient design of firewater and firefighting foam system is dynamic in controlling fire-related emergencies. The paper deals with the in-depth conceptualization of the design and analysis of firefighting systems for a typical petroleum handling, processing and storage facility in compliance with international standards. The study is aimed to formulate the elementary technique for designing an optimized firefighting system. The proposed objective was achieved by considering an ideal tank farm site that is most commonly located in a range of terminal stations, pumping stations, petroleum refineries, well sites, etc. Sufficient illumination was enumerated on the standardized classification of the liquid fuel product with respect their flammability range. Special guidelines regarding firefighting system design basis were defined and an optimized firefighting and foam system design was developed. Moreover, sufficient limitations that must be considered during the firefighting of huge tank fires are discussed. This comprehensive numerical design philosophy offers a simple and wide-ranging guide to industrial practitioners by formulating the principles for industrial firefighting system design.

Technical Language Processing for Efficient Classification of Failure Events for Safety Critical Equipment

Previous research has investigated how automated annotation and technical language processing of maintenance work orders can support maintenance decisions for different types of equipment, e.g., Sexton et al. (2018) and Brundage et al. (2021). The objective of this paper is to investigate how technical language processing can be utilized for efficient and automated classification of failure events for safety critical equipment on petroleum facilities (e.g., gas detectors and shutdown valves). For such equipment, maintenance decisions are heavily influenced by the consequence of a failure, e.g., if the failure is classified as critical or degraded, or dangerous or safe.
 To explore the possibilities for automated classification of failure events, the paper will first present the fundamental concept hierarchy needed during annotation of safety critical equipment on petroleum facilities. This hierarchy is based on previous work where taxonomies from the ISO 14224:2016 standard (ISO 14224, (2016)) have been operationalised and detailed for safety critical equipment. The concept hierarchy is tested by a group of experts on a set of notifications to ensure that it is fit for purpose. The results from the test group are then used to refine the concept hierarchy before a larger group of persons, having different roles in the petroleum industry, is engaged in the entity typing of notifications. This entity typing will then provide the basis for mapping informal technical language to a computable format. By combining this knowledge with available structured information, such as failure mode and detection method, it is expected that an automated, standardised, and more efficient classification of failure events will be possible. Our database of several thousand manually classified notifications collected during the last decade, will finally enable us to evaluate the performance of the automated classification.

Cancer Incidence and Mortality among Petroleum Industry Workers and Residents Living in Oil Producing Communities: A Systematic Review and Meta-Analysis.

Petroleum extraction and refining are major sources of various occupational exposures and of air pollution and may therefore contribute to the global cancer burden. This systematic review and meta-analysis is aimed at evaluating the cancer risk in petroleum-exposed workers and in residents living near petroleum facilities. Relevant studies were identified and retrieved through PubMed and Web of Science databases. Summary effect size (ES) and 95% confidence intervals (CI) were analysed using random effect models, and heterogeneity across studies was assessed (I2). Overall, petroleum industry work was associated with an increased risk of mesothelioma (ES = 2.09, CI: 1.58–2.76), skin melanoma (ES = 1.34, CI: 1.06–1.70 multiple myeloma (ES =1.81, CI: 1.28–2.55), and cancers of the prostate (ES = 1.13, Cl: 1.05–1.22) and urinary bladder (ES = 1.25, CI: 1.09–1.43) and a decreased risk of cancers of the esophagus, stomach, colon, rectum, and pancreas. Offshore petroleum work was associated with an increased risk of lung cancer (ES = 1.20; 95% CI: 1.03–1.39) and leukemia (ES = 1.47; 95% CI: 1.12–1.92) in stratified analysis. Residential proximity to petroleum facilities was associated with childhood leukemia (ES = 1.90, CI: 1.34–2.70). Very few studies examined specific exposures among petroleum industry workers or residents living in oil producing communities. The present review warrants further studies on specific exposure levels and pathways among petroleum-exposed workers and residents living near petroleum facilities.

Enhance the ICS Network Security Using the Whitelist-based Network Monitoring Through Protocol Analysis

In our present technological age, most manual and semi-automated tasks are being automated for efficient productivity or convenience. In particular, industrial sites are rapidly being automated to increase productivity and improve work efficiency. However, while networks are increasingly deployed as an integral part of the automation of industrial processes, there are also many resultant dangers such as security threats, malfunctions, and interruption of industrial processes. In particular, while the security of business networks is reinforced and their information is not easily accessible, intruders are now targeting industrial networks whose security is relatively poor, wherein attacks could directly lead to physical damage. Therefore, numerous studies have been conducted to counter security threats through network traffic monitoring, and to minimize physical loss through the detection of malfunctions. In the case of industrial processes, such as in nuclear facilities and petroleum facilities, thorough monitoring is required as security issues can lead to significant danger to humans and damage to property. Most network traffic in industrial facilities uses proprietary protocols for efficient data transmission, and these protocols are kept confidential because of intellectual property and security reasons. Protocol reverse engineering is a preparatory step to monitor network traffic and achieve more accurate traffic analysis. The field extraction method proposed in this study is a method for identifying the structure of proprietary protocols used in industrial sites. From the extracted fields, the structure of commands and protocols used in the industrial environment can be derived. To evaluate the feasibility of the proposed concept, an experiment was conducted using the Modbus/TCP protocol and Ethernet/IP protocol used in actual industrial sites, and an additional experiment was conducted to examine the results of the analysis of conventional protocols using the file transfer protocol.

Assessing and zoning of typhoon storm surge risk with a geographic information system (GIS) technique: a case study of the coastal area of Huizhou

Abstract. Storm surge is one of the most destructive marine disasters to life and property for Chinese coastal regions, especially for Guangdong Province. In Huizhou city, Guangdong Province, due to the high concentrations of chemical and petroleum industries and the high population density, the low-lying coastal area is susceptible to the storm surge. Therefore, a comprehensive risk assessment of storm surge over the coastal area of Huizhou can delimit zones that could be affected to reduce disaster losses. In this paper, typhoon intensity for the minimum central pressure of 880, 910, 920, 930, and 940 hPa (corresponding to a 1000-, 100-, 50-, 20-, and 10-year return period) scenarios was designed to cover possible situations. The Jelesnianski method and the Advanced Circulation (ADCIRC) model coupled with the Simulating Waves Nearshore (SWAN) model were utilized to simulate inundation extents and depths of storm surge over the computational domain under these representative scenarios. Subsequently, the output data from the coupled simulation model (ADCIRC–SWAN) were imported to the geographic information system (GIS) software to conduct the hazard assessment for each of the designed scenarios. Then, the vulnerability assessment was made based on the dataset of land cover types in the coastal region. Consequently, the potential storm surge risk maps for the designed scenarios were produced by combining hazard assessment and vulnerability assessment with the risk matrix approach. The risk maps indicate that due to the protection given by storm surge barriers, only a small proportion of the petrochemical industrial zone and the densely populated communities in the coastal areas were at risk of storm surge for the scenarios of 10- and 20-year return period typhoon intensity. Moreover, some parts of the exposed zone and densely populated communities were subject to high and very high risk when typhoon intensities were set to a 50- or a 100-year return period. Besides, the scenario with the most intense typhoon (1000-year return period) induced a very high risk to the coastal area of Huizhou. Accordingly, the risk maps can help decision-makers to develop risk response plans and evacuation strategies in coastal communities with a high population density to minimize civilian casualties. The risk analysis can also be utilized to identify the risk zones with the high concentration of chemical and petroleum industries to reduce economic losses and prevent environmental damage caused by the chemical pollutants and oil spills from petroleum facilities and infrastructures that could be affected by storm surge.

Hurricane Risk Assessment of Petroleum Infrastructure in a Changing Climate

Hurricanes threaten the petroleum industry in the United States and are expected to be influenced by climate change. This study presents an integrated framework for hurricane risk assessment of petroleum infrastructure under changing climatic conditions, calculating risk in terms of monetary loss. Variants of two synthetic probabilistic storms and one historical storm (Hurricane Ike) are simulated using the SWAN+ADCIRC model, representing a range of potential scenarios of impacts of a changing climate on hurricane forward speed and sea-level rise given uncertainties in climate projections. Model outputs inform an infrastructure impact and cascading economic loss analysis that incorporates various sources of uncertainty to estimate five types of losses sustained by petroleum facilities in surge events: land value loss, process-unit damage loss, cost of spill clean-up and repair of aboveground storage tanks, productivity loss, and civil fines. The proposed risk assessment framework is applied as a case study to seven refineries along the Houston Ship Channel (HSC), a densely-industrialized corridor in Texas. The results reveal that either an increase in mean sea level or a decrease in storm forward speed increases the maximum water elevations in the HSC for storms that produce maximum wind setup in Galveston Bay (FEMA 33 and FEMA 36), resulting in larger economic loss estimates. The role of refinery features such as storage capacity and average elevation of the refinery and its critical equipment in the refinery response to hurricane hazards is studied, and the probability distribution of refinery total loss and the loss risk profile in different hurricane scenarios are discussed. Loss estimates are presented, demonstrating the effects of hurricane forward speed and sea level on the losses for the refineries as well as the HSC. Such a framework can enable hurricane risk assessment and loss estimation for petroleum infrastructure to inform future policies and risk mitigation strategies. Potential policy implications for a region like the HSC are highlighted herein as an illustration.

Evaluation of Diffusivity and Wettability of Crude Oil-Contaminated Sand from Offshore Petroleum Facility Prior to Remediation Process

Cleansing of crude oil-contaminated sand is anticipated to rely heavily on the ability of cleaning solution to access the contamination sites and the bonding strength between crude oil and sand. In this research, the actual produced sand sample from an oilfield and reference sand sample taken from a beach were subjected to porosity, permeability, and wettability tests. Results revealed that the particle size of the sands dominated the porosity and permeability outcomes. While the porosity of the reference sand at 46.64% was barely higher than the produced sand, the permeability (in Darcy) of the former exceeded the latter by 10 folds. In wettability and interfacial study, the highest adhesion strengths at the oil-sand interface were calculated according to Young-Dupre equation. The computed values were 58.42 mN/m for the reference sand and 65.88 mN/m for the produced sand, assuming 3-species geometric-mean model from Owen/Wendt theory. The types of intermolecular bonding at the interface were dispersive (London dispersion force from Van der Waals bonding), dipole-induced dipole attraction and mechanical adhesions, justifiable through elementary analysis. All the findings including corroboration from thermogravimetric analysis suggest that relatively higher energy was required to remediate the produced sand from oil reservoir as compared to the reference sand retrieved from shoreline.

Ozone (O3) ambient levels as a secondary airborne precursor in Fahaheel urban area, the State of Kuwait

AbstractTwo years of continuous monitoring data over two time‐spans (2004–2005 and 2014–2015) were used to investigate the relationship between ozone (O3) and nitrogen oxides (NOX ≈ NO + NO2) in Fahaheel urban area (Kuwait). Their relationship was used to understand their chemical reactions and the NO2 and O3 concentration ratio to gain an insight into the sources of total atmospheric oxides (OX = O3 + NO2) levels. A Chemical Mass Balance (CMB) model was developed to detect likely point sources around the monitoring station and quantify their contribution to the overall air pollution load. Hourly diurnal variations in O3 ground level concentrations during weekends showed a slight increase in O3 levels. In addition, it was observed that overall hourly average O3 concentration reached higher levels during weekdays and weekends in 2004–2005 compared to 2014–2015. The concentration of photochemical oxidants (e.g., O3 and NO2) can be decreased by controlling the emissions of their precursors; NOX and VOCs. The net effect of NOX emissions on O3 concentrations was negative with a weak exponential decline correlation between NOX and O3, indicating Fahaheel urban area's VOC‐sensitive characteristics. For all years considered, the slopes of the linear OX–NOX relationships were higher during daytime compared to night‐time, showing that NO2 oxidations were dominant during daytime and that O3 net production was high. The study also showed the high NOX oxidation level and the possible presence of O3 net production. The slopes during night‐time indicated that NO2 consumption exceeded its formation rate. During day and night‐time, the NO2/NOX ratio was found to decline significantly as newly emitted NOX increased, supporting the area's VOC‐sensitive nature. By setting up a CMB model around the Fahaheel receptor point, it was revealed that downstream petroleum facilities have been the major contributor to pollutants environmental load over the years.

A review about radioactivity in TENORMs of produced water waste from petroleum industry and its environmental and health effects

Produced water that detached from petroleum production process is often reimbursed into the surrounding environment. This might have negative impact for environment; it is usually infiltrate agricultural soil and contaminate groundwater with toxic elements. These waters are often contaminated by technologically enhanced naturally occurring radioactive materials (TENORMs). It may create specific environmental issues and health radiological threats to the inhabitants, especially inside the petroleum facilities or the local population that live in areas and use the groundwater for the usual living purposes. The aim of this work is to provide an intensive review for the previous studies on the (TENORMs) that associating with the produced water from petroleum industry, and its environmental and health impacts in many areas around the globe. It is true that there is long term hazard associated with widespread behaviour of releasing produced water into the environments for both workers and local inhabitants as well as the environment itself. However, there is many studies suggesting that currently the situation could be considered in low hazard level in most of petroleum fields, but with increases in the extraction and use of petroleum, the discharge of produced water into the environment increases accordingly, this might be end up with negative impacts on the environment and health such as radiological contamination of aquatic and agricultural life.

Application of Remote Sensing for Impacts Assessment of Petroleum Activities and Facilities in Bongor Basin, Chad Republic

The objective of this study is to compare various changes of ecological parameters within time period prior petroleum activities and after facilities establishment in Bongor basin. Analysis of landsat 7 images from March 24 to April 5, 2000 and that of landsat 8 from February 13, 2015, before and after oil operations respectively, made it possible to extract four biophysical indices, namely: brightness index of soil, moisture index, greenness index and vegetation index. Maps of land use, hydrology and pedology were established from the analysis of multispectral parameters variations. Significant variations between two study periods were then evaluated to be either increasing, declining or stable over the entire Bongor basin and in the areas of the basin under operations. It appears that, shrub savanna has declined by 15.75% over the entire Bongor basin and by 18.90% in the areas of oil operations in Bongor basin. Floodplain and the water body have also declined by 1.59% and 0.0007% respectively over the whole Bongor basin and loss of paddy field. Agricultural area has increased by 15.15% in Bongor basin and by 14.40% in the operations area of Bongor basin, with industrial area occupying 4.49% and the expansion of urbanized area of 0.01%. Silting up of flood zone over the entire Bongor basin has increased by 0.35%. Areas under oil operations, illustrate impacts of activities on soil, trees and groundwater.

Reflectance and imaging spectroscopy applied to detection of petroleum hydrocarbon pollution in bare soils

Accidental releases of hazardous waste related to the extraction, refining, and transport of oil and gas are inevitable. Petroleum facilities and intrinsic pipelines present environmental pollution risks, threatening both human health and ecosystems. Research has been undertaken to enhance the conventional methods for monitoring hazardous waste problems and to improve time-consuming and cost-effective ways for leak detection and remediation process. In this study, both diffuse and imaging (hyperspectral) reflectance spectroscopy are used for detection and characterization of petroleum hydrocarbon (PHC) contamination in latosols. Laboratory and field measurements of PHC-contaminated and PHC-free soils were collected from an oil facility using an ASD FieldSpec-3 high-resolution portable spectrometer (2150 channels) covering visible, near infrared and shortwave infrared wavelengths (VNIR-SWIR: 350–2500 nm). The hyperspectral image dataset was acquired with the ProSpecTIR-VS airborne sensor using 357 channels in the VNIR-SWIR range at 1 m of spatial resolution. Narrow intervals of reflectance spectra were analyzed to identify the primary mineral and PHC absorption bands in soil samples and to investigate the spectral match with airborne hyperspectral data. The Multiple Endmember Spectral Mixture Analysis (MESMA) method was employed in three hierarchical levels to classify the hyperspectral imagery. The classification product yielded from MESMA model at the fourth level was 98% accurate in discriminating contaminated soils. The results demonstrated the applicability of both diffuse reflectance and imaging (hyperspectral) spectroscopy to identify bare soils contaminated by PHC leaks and spills. These technologies can also provide useful information for remediation initiatives, thereby avoiding further problems with hazardous waste.