Hyperspectral Remote Sensing Detection of Marine Oil Spills Using an Adaptive Long-Term Moment Estimation Optimizer

Marine oil spills can damage marine ecosystems, economic development, and human health. It is important to accurately identify the type of oil spills and detect the thickness of oil films on the sea surface to obtain the amount of oil spill for on-site emergency responses and scientific decision-making. Optical remote sensing is an important method for marine oil-spill detection and identification. In this study, hyperspectral images of five types of oil spills were obtained using unmanned aerial vehicles (UAV). To address the poor spectral separability between different types of light oils and weak spectral differences in heavy oils with different thicknesses, we propose the adaptive long-term moment estimation (ALTME) optimizer, which cumulatively learns the spectral characteristics and then builds a marine oil-spill detection model based on a one-dimensional convolutional neural network. The results of the detection experiment show that the ALTME optimizer can store in memory multiple batches of long-term oil-spill spectral information, accurately identify the type of oil spills, and detect different thicknesses of oil films. The overall detection accuracy is larger than 98.09%, and the Kappa coefficient is larger than 0.970. The F1-score for the recognition of light-oil types is larger than 0.971, and the F1-score for detecting films of heavy oils with different film thicknesses is larger than 0.980. The proposed optimizer also performs well on a public hyperspectral dataset. We further carried out a feasibility study on oil-spill detection using UAV thermal infrared remote sensing technology, and the results show its potential for oil-spill detection in strong sunlight.

Geochemical characteristics and localization of heavy oil fields in the Republic of Tatarstan, Russia

High-viscosity oil belong to unconventional sources of hydrocarbon raw materials, the share of which is growing every year. The development of this complex type of raw material requires modern scientific technologies in order to maintain the production of hydrocarbons at the same level. Technologies for the extraction and processing of heavy oil are different from traditional ones. First of all, these deposits are located at a shallow depth, but are classified as difficult to recover due to the complex geological structure and high anomalous oil viscosity. The objective of this work is a deeper understanding of the geochemical composition of heavy oil deposits, taking into account the peculiarities of their geological structure. This is important for the successful development of new and improvement of existing technologies for the extraction and processing of heavy oil and the implementation of the resource potential of heavy oils in the Republic of Tatarstan. Keywords: heavy oil; unconventional oil; biodegradation; GC-MS; geochemical methods.

A Comparative Analysis of Vanadyl Porphyrins Isolated from Resins of Heavy Oils with High and Low Vanadium Content

The composition of purified vanadyl porphyrins recovered from the resins of heavy oils possessing high and low vanadium contents was investigated. Vanadium content in the resins of the heavy oils under study differs by a factor of ca. 15. To recover and purify vanadyl porphyrins from the resins, extraction by N,N–dimethylformamide (DMF) with subsequent two-stage column chromatography on silica gel and sulfocationite were employed. The change of structural-group composition and content of vanadyl porphyrins in the products obtained at each stage was evaluated using Fourier IR and UV-Vis spectroscopy. Analysis of the purified vanadyl porphyrins using MALDI mass spectrometry determined distribution of their most abundant types (etio- and DPEP) and identified C27–C39 homologs for the resins possessing high vanadium content and C28–C39 homologs for the resins with low vanadium content.

Разработка инновационной энергосберегающей технологии очистки резервуаров путем диспергирования отложений

An obvious global trend in recent years is the increase in the proportion of viscous and heavy oils featured by high density and content of asphalt-resin-paraffin deposits. Due to the deterioration of the rheological properties of oil, the processes of its extraction, preparation in the fields, further transportation and subsequent processing have been made more difficult. The object of the study is the cleaning of oil and petroleum products storage tanks from the accumulated bottom sediments. The existing methods of tanks cleaning have been analyzed, the most promising methods and technical means for removing sediment and reducing the volume of sediment formation have been identified. The urgency of the development and implementation of innovative technologies enabling minimization of accumulation of deposit to reduce the scope of work in tank cleaning has been established. In this regard, experimental laboratory studies were conducted to determine the effectiveness of ultrasonic exposure with the occurrence of cavitation on the rheological properties of oil. The obtained results are indicative of a positive effect of ultrasound treatment of high-paraffin oil, such effect been expressed in decreased oil viscosity. A method is proposed for cleaning the tank from bottom sediments with the use of hydraulic washout system and ultrasonic plant. That method is based on the use of the cavitation effect caused by high-frequency waves, which makes it possible to temporarily adjust the rheological properties of oil and sludge deposit, reduce the deposit deposition rate and thereby slow down the process of sediment deposition during the storage of oil and petroleum products in large-volume tanks. Очевидной тенденцией последних лет в мире является увеличение доли вязких и тяжелых нефтей, характеризующихся высокой плотностью и содержанием асфальтосмолопарафиновых отложений. Вследствие ухудшения реологических свойств нефти затрудняются процессы ее добычи, подготовки на промыслах, дальнейшей транспортировки и последующей переработки. Объектом исследования является очистка резервуаров для хранения нефти и нефтепродуктов от образующихся донных отложений. Проанализированы существующие способы очистки резервуаров, выявлены наиболее перспективные методы и технические средства для удаления осадка и снижения объема образования отложений. Установлена актуальность вопроса разработки и использования инновационных технологий, позволяющих минимизировать выпадение осадка с целью уменьшения объема работ при очистке резервуаров. В этой связи проведены экспериментальные лабораторные исследования для определения эффективности ультразвукового воздействия с возникновением кавитации на реологические свойства нефти. Полученные результаты свидетельствуют о положительном эффекте обработки ультразвуком высокопарафинистой нефти, который выражается в снижении ее вязкости. Предложен способ очистки резервуара от донных отложений с применением гидравлической системы размыва и ультразвуковой установки. Он основан на использовании эффекта кавитации, вызываемой посредством высокочастотных волн, что позволяет провести временную корректировку реологических свойств нефти и осадка нефтешлама, снизить скорость выпадения осадка и таким образом замедлить процесс образования отложений при хранении нефти и нефтепродуктов в резервуарах большого объема.

Influence of Carbonate Minerals on Heavy Oil Oxidation Behavior and Kinetics by TG-FTIR

The impact of rock minerals on the performance of in situ combustion (ISC) techniques for enhanced oil recovery (EOR) is very important. This work is aimed at investigating the influence of carbonate rocks (dolomite and calcite) on heavy oil oxidation by Thermogravimetry–Fourier-Transform-Infrared (TG-FT-IR) coupled analysis. Two heavy oils with 19.70° and 14.10° API were investigated. Kinetic analysis was performed using TG data by differential and integral isoconversional methods. From TG-DTG curves, three reaction stages, i.e., low-temperature oxidation (LTO), fuel deposition (FD), and high-temperature oxidation (HTO), were defined for both two heavy oil samples, and their reaction mechanism was explained combining the FT-IR data. After the addition of calcite or dolomite, three reaction stages became two with the disappearance of FD, and a significant shift of reaction stages into lower temperatures was also observed. These significant changes in oxidation behavior are because calcite and dolomite promoted the coke formation and combustion by reducing the activation energy barrier and changing reaction pathways, which results in a smooth transition from LTO to HTO. Dolomite exhibited a slightly better promotion effect on LTO-FD than calcite, while calcite exhibited a better acceleration effect on FD-HTO than dolomite in terms of shifting reaction stages. Generally, calcite exhibited a better catalytic effect than dolomite. In spite of the different catalytic performance of calcite and dolomite, they do both show positive effects on combustion process regardless of the difference in the properties and composition of heavy oils. The findings in this work indicate that calcite and dolomite rocks are favorable for the ISC process, and when it comes to the ISC kinetics, the interaction between crude oil and rock must be considered.

Risk Assessment and Field Case Study on Oil/Natural Gas Explosion during High-Pressure Air Injection Process

Summary Air injection techniques have been widely applied in oil fields, but the associated safety issue of natural gas (NG) and oil explosion has been of great concern. In this study, explosion experiments of different NG compositions were conducted under high-pressure and high-temperature conditions (up to 15 MPa and 373 K) to reveal the necessary conditions for gas explosion in the air injection process. The experimental results indicate that the lower flammability limits (LFLs) and upper flammability limits (UFLs) of NGs change logarithmically with increasing pressure, which can significantly increase the explosion risk. The rise of temperature can also expand the flammability limit range. Based on the mechanisms and necessary conditions for NG and oil component explosion, fault tree analysis (FTA) models for explosion occurring during the air injection process were proposed that can provide valuable guidelines for designing anti-explosion procedures for field applications. Several explosion incidents that have occurred in air injection operations in different oil reservoirs are described, and the explosion mechanisms are analyzed. NG explosion can occur during air injection when NG is the main component present in the gas phase that can mix with air to form a combustible gas. For heavy oils with little NG, autoignited explosion of vaporized oil components can be the main reason for the incidents during the steam and air coinjection process because the autoignition temperature of heavy oil can be greatly reduced at high pressure.

Use of two vertical injectors in place of a horizontal injector to improve the efficiency and stability of THAI in situ combustion process for producing heavy oils

The current commercial technologies used to produce heavy oils and bitumen are carbon-, energy-, and wastewater-intensive. These make them to be out of line with the global efforts of decarbonisation. Alternative processes such as the toe-to-heel air injection (THAI) that works as an in situ combustion process that uses horizontal producer well to recover partially upgraded oil from heavy oils and bitumen reservoirs are needed. However, THAI is yet to be technically and economically well proven despite pilot and semi-commercial operations. Some studies concluded using field data that THAI is a low-oil-production-rate process. However, no study has thoroughly investigated the simultaneous effects of start-up methods and wells configuration on both the short and long terms stability, sustainability, and profitability of the process. Using THAI validated model, three models having a horizontal producer well arranged in staggered line drive with the injector wells are simulated using CMG STARS. Model A has two vertical injectors via which steam was used for pre-ignition heating, and models B and C each has a horizontal injector via which electrical heater and steam were respectively used for pre-ignition heating. It is found that during start-up, ultimately, steam injection instead of electrical heating should be used for the pre-ignition heating. Clearly, it is shown that model A has higher oil production rates after the increase in air flux and also has a higher cumulative oil recovery of 2350 cm3 which is greater than those of models B and C by 9.6% and 4.3% respectively. Thus, it can be concluded that for long-term projects, model A settings and wells configuration should be used. Although it is now discovered that the peak temperature cannot in all settings tell how healthy a combustion front is, it has revealed that model A does indeed have far more stable, safer, and efficient combustion front burning quality and propagation due to the maintenance of very high peak temperatures of mostly greater than 600 °C and very low concentrations of produced oxygen of lower than 0.4 mol% compared to up to 2.75 mol% in model C and 1 mol% in model B. Conclusively, since drilling of, and achieving uniform air distribution in horizontal injector (HI) well in actual field reservoir are costly and impracticable at the moment, and that electrical heating will require unphysically long time before mobilised fluids reach the HP well as heat transfer is mainly by conduction, these findings have shown decisively that the easy-and-cheaper-to-drill two vertical injector wells configured in a staggered line drive pattern with the horizontal producer should be used, and steam is thus to be used for pre-ignition heating.