Petroleum Processing Industries Research Articles

Proposing novel predictive group and atomic contribution models for hydrogen sulfide absorption by Deep Eutectic Solvents

Hydrogen sulfide (H2S) is one of the most dangerous impurities of natural gas which cause human and environmental issues. Thus, the main process of gas sweetening plants is H2S removal from natural gas. Amine solutions are the commonly used solvents for gas-sweetening processes in petroleum industries. However, amin solutions are not safe and cause many environmental issues especially in the post-process treatment of used amine. Thus, the issue of proposing green sustainable solvents for gas sweetening is vital for petroleum industries. Deep Eutectic Solvents (DESs) are the most recently introduced green solvents which have shown good capability for H2S absorption. Thus, DESs are one of the most possible candidates for green solvents to replace amine solutions. Experimental studies to choose suitable solvents is a tough challenge because working with H2S is very dangerous and requires expensive facilities. Therefore, an accurate and global thermodynamic model is necessary to predict the solubilities of H2S in DESs without the requirement of experimental data. This study for the first time in open literature, proposes two accurate and global thermodynamic models of group contribution (GC) and atomic contribution (AC) for predicting the H2S solubilities in various nature DESs. The largest and most updated data bank for H2S solubility in DESs was developed from open literature, including 415 solubility data of 37 different nature DESs. The proposed GC and AC models were developed according to the gathered data bank and their results were analyzed by statistical parameters. Both GC and AC models show normal behavior and promising results concerning experimental data by the calculated AARD% of 9.64, and 12.86, respectively.

Exploring the food-energy-water nexus in China's national industries: Insights from network structure and production disturbances

Understanding the food-energy-water nexus (FEWN) among industries' input–output activities is vital for the management of regional strategic resources. However, identifying key nexuses and quantifying their effects within an economy-wide dimension remain a challenge. This study integrated the frameworks of social network analysis (SNA) and computable general equilibrium (CGE) methods based on input–output data, presenting a new methodology to assess inter-industrial FEWN in China. Results indicated that: (1) Agriculture and catering industries were the principal food provision industries in the national economy. They also linked production activities among the food, energy, and water (FEW) sectors. (2) Fossil energy extraction industries with high betweenness centrality were the product circulation media in the industrial network. Their increased outputs could clearly boost domestic production. For instance, the yield of most national industries was expected to expand by 0.5 %–1.5 % due to a 10 % increase in coal supply. The electricity and petroleum processing industries with the highest response coefficients were the mainstays of China's economy. They exerted wide-ranging effects on other industries through short input–output paths. (3) Water-related industries could readily use products and services from other sectors and create demand-driven effects on FEW industries. In contrast, the output scale of national industries was not sensitive to changes in water input. These findings also highlighted the importance of conducting a FEWN evaluation within a balanced macroeconomic system. The proposed SNA–CGE analytical framework showcased good applicability and accuracy in the context of China and could serve as a reference method for FEWN research in other regions.

Influence of the cationic degree and molar mass of modified starches on their physicochemical properties and capability to enhance the oil recovery process

Polysaccharides and their derivatives are used as additives in numerous petroleum industrial processes, especially in enhanced oil recovery (EOR). There exists however, a lack of studies concerning how their physicochemical properties affect the oil recovery process. This work presents an investigation of a series of 2-hydroxy-3-(trimethylammonium)propyl starches (HTPS) with different molar masses and cationic degrees that are potentially useful for EOR. It was investigated surface/interfacial tensions, rheological profile, emulsion index and wettability alteration. The results provide experimental evidence that the HTPS intrinsic properties affect the measured properties. The HTPS solution/oil interfacial tension (IFT) ranged from a low value of 19.0 to a high value of 34.0 mN/m and correlates positively with the molar mass of the HTPS. In contrast, the rheological behavior displays correlations with the molar mass and the degree of cationization. Furthermore, the 1 % HTPS solutions presented around 10 % of viscosity increase in comparison to brines typically used in waterflooding. The derivative with a higher molar mass and intermediate degree of cationization (HTPS 2) was more effective in changing the wetting condition of an aged limestone with a wettability alteration index (WAI) of 52 % while the commercial surfactant cetyltrimethylammonium bromide (CTAB) presented a WAI of 32.6 %.

Determining the parameters of the oil film on the sea surface using remote sensing data

Oil spill accidents have gradually increased due to the continuous development of marine transportation and petroleum processing industries. Monitoring and managing marine oil spills present important economic, social, and practical implications in preventing offshore oil pollution and maintaining ecological balance.
 Remote sensing technologies play an increasingly important role in accurate detection and monitoring of oil spill slicks, assisting scientists in forecasting their trajectories, developing clean-up plans, taking timely and urgent actions, and applying effective treatments to contain and alleviate adverse effects.
 A method is proposed for remote sensing of an oil film on the sea surface based on irradiation with frequency-modulated laser radiation with a linear dependence of frequency on time. According to the spectrum of temporal changes in the intensity of the radiation reflected by the surface, the average thickness of the oil film, the distribution function of the oil film thickness, and the volume of spilled oil are determined.
 Taking into account the possibility of registering beat frequencies from fractions of a hertz to megahertz with modern instruments, we can talk about the possibility of measuring oil thicknesses from hundreds of angstroms to tens of meters using the proposed method of remote sensing. The method also makes it possible to additionally determine the thickness distribution function and the volume of spilled oil.
 The method proposed in this study has obvious advantages in terms of small sample size and processing efficiency and has great application potential in the field of maritime supervision.

Circular-arc array for the pulsed eddy current inspection of thermally insulated pipelines

The inspection of corrosion under insulation (CUI) has been identified as a significant challenge in the petroleum and chemical process industries. As some of the most effective strategies, pulsed eddy current (PEC) techniques have proved effective for the measurement of the CUI of pipelines. In this paper, we propose a circular-arc array (CAA) to improve the measurement efficiency for the PEC inspection of thermally insulated pipelines. Based on the PEC system model for inspecting the CUI of pipelines, the magnetic field distribution of the CAA with multiple excitors was investigated. It is shown that the coverage of induced magnetic field gets much larger than that of the single excitor to realize high-efficiency measurements. Moreover, a sparsely distributed receiver array is designed to further improve the signal-to-noise ratio by eliminating the waviness effect due to multiple excitors. Finally, experiments were conducted, and the results demonstrated the effectiveness of the proposed method for the inspection of thermally insulated pipelines.

Granular nitrogen-doped carbons with ultra-high C2H2/CO2 adsorption selectivity for C2H2 purification

Purification of C2H2 from C2H2/CO2 mixtures such as cracked gas through the adsorptive separation technology based on porous adsorbent with highly selective adsorption capability is considered as the promising and energy-efficient process in petroleum industry. Herein, granular nitrogen-doped carbons derived from coconut shell were obtained through the urea modification with steam assisted hydrothermal method followed by calcination. They were characterized and their adsorption and separation properties for C2H2/CO2 mixture were systematically investigated. It was found that they macroscopically present the uniform particle sizes (median diameter D50 at around 700 μm), and structurally have the characteristics of developed porosities (Brunauer-Emmett-Teller surface areas up to 430.2 m2/g) and abundant nitrogen-containing functional groups. In particular, their adsorption selectivities for C2H2/CO2 were significantly improved to 7.5 at 25 °C and 1.0 bar, outperforming the granular carbons without nitrogen doping (4.0) and some benchmark powdery adsorbents. Breakthrough experiments indicate that the granular nitrogen-doped carbons can be directly packed in a fixed bed to separate C2H2/CO2 mixture completely under dry conditions (relative humidity = 0 %) and humid conditions (relative humidity = 75.1 %) at 25 °C, and their dynamic separation performance could be well remained during the cyclic experiments. Molecule simulation results further reveal that the pyridinic-N with great binding energy (BE) interactes with C2H2 (-16.27 kJ/mol), and great absolute difference of binding energies (ΔBE) between C2H2 and CO2 (ΔBE pyridinic-N = 5.04 kJ/mol) plays the significant role in improving the C2H2/CO2 adsorption and separation performance of granular nitrogen-doped carbons. Therefore, the granular nitrogen-doped carbons are very promising for purification of C2H2 from C2H2/CO2 mixtures.

Detection of Marine Oil Spills Based on HOG Feature and SVM Classifier

Oil spill accidents have gradually increased due to the continuous development of marine transportation and petroleum processing industries. Monitoring and managing marine oil spills present important economic, social, and practical implications in preventing offshore oil pollution and maintaining ecological balance. Unmanned aerial vehicle (UAV) has become a suitable carrier for low-altitude oil spill detection because of their fast deployment and low cost. Thermal infrared remote sensing images are used as the research object in this study. A method around histogram of gradient (HOG) features combined with a support vector machine (SVM) is proposed for identifying oil spills at sea to improve the accuracy of offshore low-altitude oil spill recognition and realize all-weather monitoring of offshore oil spills in offshore waters. Steps for extracting HOG features and basic principles of the SVM classification are first investigated. Image preprocessing is then performed on collected thermal infrared image data to produce samples. HOG features of samples are extracted, and the radial basis function is selected as the kernel function for training the SVM classifier. HOG features of the infrared image to be tested are calculated and then sent to the classifier for identifying the oil spills. In addition, the proposed method is compared with the back propagation(BP) neural network method and local binary pattern (LBP) combined with the SVM classification method for analysis. The results show that the oil film recognition method based on the HOG feature and SVM has a recognition accuracy of 91.3% in the environment of small infrared oil film samples, which is significantly better than the BP and LBP-SVM recognition methods, and obtains a shorter training time. The method proposed in this study has obvious advantages in terms of small sample size and processing efficiency, can meet the requirements of all-weather inspection of oil film pollutants by UAV in offshore port areas, and has great application potential in the field of maritime supervision informatization in the future.

Research on Spatial Distribution Characteristics of High Haze Pollution Industries Such as Thermal Power Industry in the Beijing-Tianjin-Hebei Region

The Beijing-Tianjin-Hebei region is subject to the most severe haze condition in China. Against the backdrop of the coordinated development of Beijing, Tianjin, and Hebei, it is of great significance to explore the space-time distribution characteristics of high haze pollution industries in the above region. The purpose of this article is to find high haze pollution industries scientifically, analyze the spatial distribution characteristics of high haze pollution industries in Beijing-Tianjin-Hebei correctly, and formulate effective reduction measures for the spatial distribution of high haze pollution industries in different regions of Beijing-Tianjin-Hebei. It hopes that the measures provide a basis for effective to reduce high haze pollution in the Beijing-Tianjin-Hebei region. Using the Gini coefficient and location entropy, this paper explores the space-time characteristics of high haze pollution industries in 13 cities of the Beijing-Tianjin-Hebei region. The results show that those aforesaid high haze pollution industries present an obvious clustering trend in Beijing, Tianjin, Shijiazhuang, Handan, and some areas along the economic axis of China, overall flooding into Eastern coastal and Southern inland areas. By industry, the petroleum processing and coking processing industry, chemical raw materials and chemical products industry, manufacture of non-metallic mineral products, and ferrous metal smelting and rolling processing industry witness a declining clustering trend, as opposed to the electricity, heat production, and supply industry. Meanwhile, core cities of the Beijing-Tianjin-Hebei region have developed high haze pollution industries, and the hinterland lags in economic development. It is necessary to face up to the differences in economic development among areas in the Beijing-Tianjin-Hebei region, promote the staggered development of high haze pollution industries, and build a high haze pollution industry chain with coordinated economic and environmental development, thus reducing the economic gap with each area, and realizing the coordinated development of economy, industry, and environment.

Driving factors and key emission reduction paths of Xinjiang industries carbon emissions: An industry chain perspective

As a typical resource-based region, Xinjiang is under increasing pressure to reduce carbon emissions. The ability to identify the drivers of carbon emissions in the industry and mapping out key emission reduction paths are core components of achieving carbon emission reduction in Xinjiang. This research incorporates energy and environmental factors, constructs a hybrid input–output model of “energy-environment-economy,” and uses the environmental input–output structural decomposition (EIO-SDA) and structural path decomposition (SPD) methods to analyze the drivers of carbon emissions from energy consumption and key emission reduction paths in Xinjiang. First, it shows that the economic-scale effect and the energy-intensity effect are the biggest facilitators of carbon emissions and most significant barriers to carbon emission reduction in Xinjiang. Second, capital formation and domestic trade are the primary sources of demand driving changes in carbon emissions in Xinjiang. Third, sectors involving the production and supply of electricity and heat, such as heavy manufacturing and energy industries, including petroleum processing, coking, nuclear, fuel processing, and chemical industries, are the key sectors responsible for carbon emission reduction in Xinjiang. Last, in terms of industry chains, “metal smelting and rolling processing industry/non-metallic mineral products industry—construction industry—fixed capital formation” and “oil and gas extraction industry (S20)—(intermediate sector)—final demand” are the most important paths driving the growth and decline of carbon dioxide (CO2) emissions from Xinjiang industries, respectively. To promote Xinjiang's carbon emission reduction targets, the Xinjiang government should actively improve its energy structure, promote a change in demand growth patterns, and formulate comprehensive management policies for high-carbon-transfer industries according to an industry chain perspective.

Occupational health risk assessment of the benzene exposure industries: a comprehensive scoring method through 4 health risk assessment models

Benzene is one of the most common occupational hazards in the working environment which was in the list of group 1 carcinogens. This study applied four occupational health risk assessment models: EPA model; MOM model of Singapore; the International Council on Mining and Metals (ICMM) model, and the Technical guide WS/T 777-2021 of China. The models assessed both non-carcinogenic and carcinogenic effects of benzene for 1629 employees in 50 factories in Jiangsu Province (China) who were exposed to benzene in the working environment and analysis the risk between industries by principal component analysis (PCA) method. The highest occupational health hazard of benzene among the five industries is petroleum processing industry, then followed by chemical products manufacturing industry, special equipment manufacturing industry, wood processing and products industry, and at last the pharmaceutical manufacturing industry. The population of abnormal routine blood parameters in the subjects was mostly in the "wood products industry" group, and the concentration of benzene in "wood products industry" group is the lowest in 5 groups. The industries with low exposure concentration have higher blood abnormality rates; this may be caused by the fact that blood damage is more secretive under low occupational health risk.

Flow Velocity Gradient of Refined Hydrocarbon and Viscous Fluid in A Single Stage Symmetrical Bifurcated Channel

A single stage bifurcated system in its wide spectrum of applications in the petroleum and gas processing industry, chemical industry and civil engineering industry, in the distribution and recovery of processed and unprocessed fluid and materials. Considered in this experimental investigation of the impact of a single stage symmetrical bifurcated system on the flow of viscous fluid and refined hydrocarbon to truly establish a relationship between specific dimensions of symmetrical bifurcated flow channels and the physical properties of various classes of fluid samples. Peanut oil and diesel were selected to respectively represent viscous fluid and refined hydrocarbon, as they are allowed to flow through some selected angles of a single stage symmetrical bifurcated channel until designated volumes of each of the fluid samples are recovered into a recovery beaker. Profile of results presented from the experimental study reveals a trend with a sharp negative velocity gradient for small flow time corresponding to smaller
 recovery volume and a much lower velocity gradient for relatively higher flow time for higher recovery volume for less viscous and dense diesel oil representing refined hydrocarbon and a more viscous and dense peanut oil represented by the trend with a lower negative velocity gradient. The implication of the results obtained is that bifurcated systems offer flow stability in a continuous flow situation, and also observed from the results is the confirmation of the existence of velocity gradient between opposite wall of the branched channels, which further reveals where the flow state will eventually begin to graduate into turbulence. The study can be extended by investigating the impact of two-stage or multiple level bifurcated network system on flow structure and stability, and how the pressure based on the level of fluid in the reservoir is related to the flow velocity and stability.

Characteristics and Assessment of Heavy Metal Contamination in Soils of Industrial Regions in the Yangtze River Economic Belt

The Yangtze River Economic Belt is one of the areas with rapid economic development in China, although the intensive industrial activities have aggravated the emissions of soil pollutants in this area. Industrial activities are important sources of soil heavy metal contamination; however, the spatial distribution and main emission sources of soil heavy metal contamination in industrial regions of the economic belt remain unclear. Here, we collected data on the concentrations of eight heavy metals (Cd, Cr, Cu, Pb, Ni, Hg, As, and Zn) in the surface soils of 193 industrial regions covering 11 provinces and cities of the Yangtze River Economic Belt from China National Knowledge Infrastructure (CNKI), Web of Science, and other public databases. On this basis, we analyzed the spatial distribution characteristics of heavy metals and the contamination characteristics of typical industries. The results showed that the heavy metal contamination in agricultural land was more serious than that in industrial land. A total of 58.49%, 39.53%, and 22.64% of the agricultural land, respectively, contained levels of Cd, Zn, and Pb that exceeded the screening values of the Soil Environmental Quality Control Standard for Soil Pollution Risk of Agricultural Land (GB 15618-2018). The results of geo-accumulation index analysis showed that the contamination degree of the eight heavy metals was in the order of Cd (2.52)>Hg (1.17)>Pb (1.00)>Zn (0.90)>Cu (0.72)>As (0.02)>Cr (-0.40)>Ni(-0.48). As for the spatial distribution, Hg, Cd, As, Cu, Pb, and Zn were the main pollutants in the upstream and middle reaches of the industrial regions, whereas As, Cd, and Hg were the main pollutants in the downstream industrial regions. Different types of industry caused different types of contamination. Mining industries caused the most serious soil contamination, the main pollutants of which were Hg and Cd, followed by Cu, Pb, and Zn. Furthermore, metal processing industries mainly caused Cd and Pb contamination. The surrounding soils of chemical industries were contamination-free or only slightly polluted by the eight heavy metals, whereas petroleum processing industries mainly caused Cd contamination. Our study provides important theoretical basis for the future prevention and control of soil heavy metal contamination in industrial regions of the Yangtze River Economic Belt.

Monte Carlo simulation, molecular dynamic simulation, quantum chemical calculation and anti-corrosive behaviour of Citrus limetta pulp waste extract for stainless steel (SS-410) in acidic medium

Corrosion occurs as a result of acid-based cleaning process in petroleum industry. Some of the procedures require 15% hydrochloric acid (HCl) solution thus speeding the corrosion rate. In this study, Citrus limetta pulp waste was used to obtain corrosion inhibitor for stainless steel (SS)-410 in presence of 15% HCl solution. The C. limetta pulp waste extract has shown maximum 90.90% corrosion inhibition efficiency at 4 g/L in 15% HCl solution using potentiodynamic polarization analysis. Scanning electron microscopy, atomic force microscopy and X-rays diffraction study confirmed the adsorption of the pulp waste extract on the SS surface. The pulp waste extract followed Langmuir adsorption isotherm thus confirming monolayer formation on the surface of SS-410. Theoretical and computational studies confirmed that Linalool was main phytochemical responsible for anti-corrosive effect. Linalool and SS-410 surface interactions was studied using molecular simulation. Overall, C. limetta pulp waste extract has shown anti-corrosive behaviour in 15% hydrochloric acid on SS-410 surface.

CAST UYGULAMASI: CAPECO ÇOKLU TANK PATLAMASI ÖRNEK ÇALIŞMA

Although major industrial accidents caused by hazardous chemicals such as petroleum products are rare in the chemical and petroleum processing industries, they cause significant financial losses, deaths and serious environmental impacts. Even though traditional accident investigation methods work well for linear systems, an accident analysis method built on systems theory helps to analyze major industrial accidents. This study analyzes the Caribbean petroleum tank terminal explosion using Causal Analysis based on Systems Theory (CAST) method. The main purpose of this research is to examine the causes of the accident with a risk assessment based on systems theory apart from traditional methods. The Caribbean petroleum tank terminal explosion was chosen for the study because it was one of the largest tank accidents in the last 50 years. In order to prevent future accidents, it is of great importance to analyze past accidents by analyzing them with new methods. For this purpose, various data and documents related to CAPECO accidents were examined in detail within the framework of CAST methodology. The CAST analysis revealed direct and indirect causal factors related to the CAPECO accident. The lack of management standardization and operational systems were the leading direct causes for the accident. Other main reasons were identified as the absence of an independent automatic overfill prevention system, a lack of considerations on the worst-case scenario, unreliable critical equipment, and inability to detect a large overflowing vapor cloud spreading into the terminal area. The study indicates that CAST methodology can reveal many causal factors at different hierarchical levels of a system.

Potential Role of Nanomaterial’s In Oil and Gas Industry: Review on Downstream Stream Processing

Nanotechnology is the modern way of developing the products, which results the high efficiency of nanomaterial’s use in the hydrocarbon recovery processes. Due to unique physico-chemical properties of nonmaterial have lead to their application in the field of petroleum processing industries, such as exploration, reservoir characterization, drilling, cementing, production and stimulation, enhanced oil recovery (EOR), refining and processing. In this review applications of nanotechnology through nano-catalysis in petro-refining processes, recent development of nonmaterial’s were summarized. Finally, an outlook on the current challenges and some prospects for the future applications is also highlighted.

Base-free catalytic aerobic oxidation of mercaptans over MOF-derived Co/CN catalyst with controllable composition and structure

The oxidation of mercaptans under mild and base-free conditions is of vital importance in terms of economy and environment for petroleum processing industry. Here, we developed a series of MOF-derived cobalt-based nitrogen-doped (N-doped) carbon (Co/CN-x) catalysts for the base-free catalytic oxidation of mercaptans. The optimal Co/CN-900 showed excellent catalytic activity for the oxidation of mercaptans under base-free conditions, yielding complete conversion of various mercaptans and > 99.0% selectivity of disulfides. The high performance can be contributed to the advantages of hierarchical pore structure for the diffusion and migration of substrates, self-carrying alkalinity for the formation of mercaptide anion, abundant active Co sites for catalytic oxidation of mercaptans as well as the synergistic effects between the Co nanoparticles (NPs) and N-doped carbon supports. Furthermore, a possible mechanism for base-free catalytic oxidation of mercaptans over Co/CN-x catalysts is proposed based on a set of control experiments and density functional theory (DFT) calculations.

Biodegradation mechanism of naphthalene using marine sponge symbiotic bacteria

Generally, all petroleum processing industries produce oil sludge or sludge. Polycy-clic Aromatic Hydrocarbons (PAH), one of the components contained in sludge, are hazardous and toxic waste material with toxic, carcinogenic and mutagenic properties. The research objective was to understand the biodegradation mechanism of naphthalene by utilizing a marine sponge symbiotic bacterial isolate. Partial bacteria Bacillus Sp strain AB353f (BC), sponge isolate Neopetrosia sp and Acinetobacter Calcoaceticus strain PHCDB14 (AC) isolate sponge Callyspongia (Aerizusa) as biomaterial for PAH degradation. Biodegradation method integrates bacterial suspension with 10,000 ppm naphthalene for 25 days. Every 5 days, the bio-degradation indicators were observed and the products of the destruction of naphthalene components were measured using FTIR and GC-MS. The results showed that BC isolates and AC isolates from sponge symbionts could degrade naphthalene. The biodegradation performance of BC bacteria tended to be more dominant than AC against naphthalene. Based on the functional groups resulting from FTIR, three types of biodegradation products were identified, namely: alcohol, aldehyde and carboxylic acid and one transition product in the form of a cate-chol. Maximum naphthalene bio-degradation occurs at an interaction period of 20 - 25 days.

Molecular dynamic insight into solubility of H2S in ionic liquids [emim][BF4], [emim][OTf] and [emim][Tf2N

Natural gas sweetening is one of the important processes in petroleum industry. Ionic liquids (ILs) as a new class of compounds are an alternative to conventional solvents to achieve this goal. In this study, the solubility of H2S gas in ionic liquids 1-Ethyl-3-methylimidazolium tetrafluoroborate ([emim][BF4]), 1-Ethyl-3-methylimidazolium trifluoromethanesulfonate ([emim][OTf]) and 1-Ethyl-3-methylimidazolium bis (trifluoromethylsulfonyl)imide was calculated based on the excess chemical potential energy by molecular dynamics free energy perturbation (FEP) technique. In this regard, validation was carried out for force fields of gas and ILs. Two force fields, All-Atom (A-A) and United-Atom (U-A), were compared to calculate the H2S solubility in the ILs. The performance of A-A force field was better for [emim][BF4] and [emim][OTf]; whereas, that of U-A force field for [emim][Tf2N]. The calculated Henry’s constant and chemical potential energy were in a good agreement with experimental data. The results showed that higher negative potential energy resulted in higher molar fraction and the ionic liquid [emim][BF4] had the best performance for H2S removal from a gas stream.

A fully implicit EOS based compositional two-phase transient flow simulator in wellbores

Transient two-phase flow in pipes and wellbores appears in several processes in petroleum industry. Predicting pressure, temperature and composition behavior during offshore well tests can support investment decisions in exploration. The governing system of equations that model production (or injection) and build-up (or fall off) is composed by the mass conservation of each component, the transport equation for each phase and one overall system energy equation. In this paper we develop a fully implicit equation of state based thermal compositional simulator able to model two-phase multicomponent flow in wellbores and pipes. This simulator is fully compositional and includes thermal effects. The thermodynamics calculations are based on the Peng-Robinson equation of state, and the momentum equations are based on the Single-Pressure Two-Fluid model. The finite volume method is used to discretize the non-linear system of equations, and time is discretized using Euler's implicit technique. The obtained numerical solutions for both co-current as well as countercurrent flow showed excellent agreement when compared to benchmark solutions published in the literature. A well kick-off followed by constant flow rate production and posterior shut-in was also simulated and the numerical results were discussed. It also models surge pressure and gravitational segregation effects in the wellbore. The presented simulator may be applied in numerical pressure transient analysis and pressure behavior in flowlines connecting wellheads and production platforms.

Investigation of Biodegradable Bacteria as Bio indicators of the Presence of PAHs Contaminants in Marine Waters in the Marine Tourism Area of Makassar City

The activities of the petroleum processing industry and marine transportation potentially cause of hydrocarbon pollution. It is assumed that every water area exposed to hydrocarbons also found bacterial species that have biodegradation properties against PAH contaminants. This study aims to analyze the relationship between biodegradable bacteria and the status of marine waters exposed to hydrocarbons. The method of analyzing the type of PAH contaminants for each seawater and sponge samples were processed at 4 different points using GC-MS, the same sample was also carried out isolation, characterization and activity test of bacterial isolates against naphthalene and pyrene type PAH. The analysis showed that the four samples of seawater were contaminated with hydrocarbons. The type of hydrocarbons found in each sample is different and the concentration value varies. The types of bacteria identified in seawater and sponge samples also varied. There were 8 types of isolates selected, each one isolate per sample, all of which showed biodegradation activity against hydrocarbon contaminants, while the order of aromatic contamination levels at the four sampling points Sp. 1 > Sp.2 > Sp.3 > Sp.4. These results indicate that the presence of biodegradable bacteria in water areas can be a bio-indicator for the presence of PAH pollutants.