Accurate prediction of erosion rates in polymeric and composite materials is essential for their effective design and maintenance in diverse industrial environments. This study presents a predictive modelling framework developed using the JMP Pro machine learning integrated system to estimate erosion rates of polymers and polymer composites. For better model generalisation under various conditions, a curated dataset was compiled from peer-reviewed literature, standardised, and subjected to outliers and multivariate exploratory data analysis to identify dominant variables. The model utilises key input parameters, including impact angle, impact velocity, sand content, particle size, material type, and fluid medium, to predict the erosion rate as the target output variable. Six machine learning algorithms were evaluated through a systematic model comparison process, and two were selected. Model performance was assessed using robust error metrics, and the interpretability of erosion behaviour was validated through prediction profilers and variable importance analyses. Artificial Neural Network (ANN) and Extreme Gradient Boosting (XGBoost) demonstrated the best training and validation performance based on the evaluation metrics. While both models yielded high training performance, the ANN model demonstrated superior predictive accuracy and generalisation capability across a broad range of conditions. Beyond prediction, the model outputs also showed a meaningful representation of the influence of input variables on erosion rates.

The primary aim of this research is to analyze and evaluate the design of a composite tube that is structurally embedded with distributed fiber optic sensors to enable real-time monitoring in challenging subsea environments, especially associated with subsea drilling and well-completion applications. This investigation utilizes the Finite Element Analysis (FEA) based numerical simulations tool to assess the feasibility from the perspective of structural integrity and reliability. This research analyses the mechanics of polymers and reinforced resin composite materials embedded with DFO. Emphasis is given to the angle and placement of different DFO sensing methods to match the composite lay-up and design premise. Two sensor lay-up scenarios, longitudinal and helically wrapped up, are analyzed for cross-section and longitudinal span design under various loading conditions. The helical lay-up of DFO placed in a grooved slot on the outskirts of the thermoplastic inner shell demonstrates promising results in the burst, axial compression, buckling, and reeling loading cases. The stress results are presented in a ply-by- ply manner for each lay-up for composite design, together with the stress results of the thermoplastic pressure barrier layer. These results establish a sound technical basis for the proposed design scenarios.

The technique of Enhanced Gas Recovery by CO2 injection (CO2-EGR) into shale reservoirs has brought increasing attention in the recent decade. CO2-EGR is a complex geophysical process that is controlled by several parameters of shale properties and engineering design. Nevertheless, more challenges arise when simulating and predicting CO2/CH4 displacement within the complex pore systems of shales. Therefore, the petroleum industry is in need of developing a cost-effective tool/approach to evaluate the potential of applying CO2 injection to shale reservoirs. In recent years, machine learning applications have gained enormous interest due to their high-speed performance in handling complex data and efficiently solving practical problems. Thus, this work proposes a solution by developing a supervised machine learning (ML) based model to preliminary evaluate CO2-EGR efficiency. Data used for this work was drawn across a wide range of simulation sensitivity studies and experimental investigations. In this work, linear regression and artificial neural networks (ANNs) implementations were considered for predicting the incremental enhanced CH4. Based on the model performance in training and validation sets, our accuracy comparison showed that (ANNs) algorithms gave 15% higher accuracy in predicting the enhanced CH4 compared to the linear regression model. To ensure the model is more generalizable, the size of hidden layers of ANNs was adjusted to improve the generalization ability of ANNs model. Among ANNs models presented, ANNs of 100 hidden layer size gave the best predictive performance with the coefficient of determination (R2) of 0.78 compared to the linear regression model with R2 of 0.68. Our developed ML-based model presents a powerful, reliable and cost-effective tool which can accurately predict the incremental enhanced CH4 by CO2 injection in shale gas reservoirs.

Mechanical degradation (erosion) of plastics in the marine environment has been reported in many literature studies but without quantitative information. This type of degradation is crucial as it accounts for most of the initial microplastic products, in marine environments (e.g., rivers and oceans). Here, we quantify the erosion of plastics by water-borne sediments under typical perpendicular water velocities and sand loads of turbid rivers and coastal oceans. Polypropylene (PP) shows the highest response to water-borne erosion, with a surface degradation rate of 5160 mu m per year (4.44 mg per mm(2) per year), compared with high-density polyethylene (HDPE) with a degradation rate of 1874 mu m per year (1.79 mg per mm(2) per year), resulting in the formation of microplastics (MPs). The rate of formation of such microplastic particles (>10 mu m), as characterised by a laser direct infrared (LDIR) chemical imaging system, amounts to 669 particles per mm(2) per year for PP and 187 particles per mm(2) per year for HDPE, exhibiting average particle sizes of 60 mu m and 23 mu m in the same order. Furthermore, surface microscopy provided valuable insights into the dominant erosion mechanisms, revealing three distinct zones and the surface features reveal the brittle erosion behaviours. These results will enable a better assessment of degradation and lifetime prediction of plastics in turbid rivers and coastal oceans, allowing precise estimation of the rate of formation of MPs.

Gas hydrate mitigation is considered a painstaking process in the oil and gas industry. Chemically, mono ethylene glycol (MEG) is used to control the gas hydrate formation. However, gas hydrate formation can also be affected by an external magnetic field under certain conditions such as subsea production equipment that can generate a magnetic field. This magnetic field could influence the physical behaviour of the gas hydrate conditions of the transported fluid within the subsea production pipelines. The objectives of this research were to assess the effects of exposing water and 20 wt % MEG solution to the magnetic field of 13,499 Gauss, neodymium magnet, on methane hydrate formation in correlation with field exposure time and memory effects. This study determined that, for the water solution, there was a proportional, incremental trend between the magnetic field exposure time and its memory effect for exposures of 172, 258 and 387 h. The dissociation temperatures of the magnetized solutions were raised and had different hydrate developments. However, no effects were found on the 20 wt % MEG solution. It has been inferred from this outcome that the addition of MEG impacted on the water molecules numbers within the hydration shell. The application of the potential magnetic effect as a control method can provide in-depth and better understanding of the hydrate behaviour and mechanism at subsea conditions.

Monoethylene glycol (MEG) is often injected into submarine transportation pipelines, from offshore oil and gas platforms, to suppress hydrate formation. MEG can be recovered, for recycling, through a MEG regeneration plant, onshore. The costs related to hydrate inhibition operations are significant; thus, introducing new methods of reducing the volumes of MEG required by the system potentially will provide significant economic benefits for the operation. The objectives of this study were to evaluate the influence of ammonium hydroxide (NH4OH), sodium hydroxide (NaOH), potassium hydroxide (KOH), and methyl diethanolamine (MDEA) on inhibition performance when separately combined with a MEG 20 wt % solution in a methane gas system. The pH levels applied were 10.96, 10.84, 10.62, and 10.07 for NaOH, KOH, NH4OH, and MDEA, respectively. The results indicated that these compounds suppressed the hydrate dissociation temperatures, to different degrees, when compared with a normal MEG 20 wt % solution. The temperatures were reduced by an average, across the range of pressures, of 0.72, 0.78, and 0.94 degrees C in the case of MDEA, KOH, and NaOH, respectively. However, when combined with NH4OH, the reduction in dissociation temperature was even more significant, averaging 1.68 degrees C. An economical assessment of the benefits of reducing the inhibition temperature by this amount, through the combination with NH4OH, indicated an operational cost saving of about 17% within the MEG regeneration process. This level of cost reduction will be of significant interest to the offshore gas-producing industry.

Development of shale gas reservoirs is the fastest growing area on a large scale globally due to their potential reserves. CO2 has a great affinity to be adsorbed on shale organic surface over CH4. Therefore, CO2 injection into shale reservoirs initiates a potential for enhanced gas recovery and CO2 geological sequestration. The efficiency of CO2 enhanced gas recovery (CO2- EGR) is mainly dominated by several shale properties and engineering design parameters. However, due to the heterogeneity of shale reservoirs and the complexity of modeling the CO2-CH4 displacement process, there are still uncertainties in determining the main factors that control CO2 sequestration and enhanced CH4 recovery in shale reservoirs. Therefore, in view of the previous sensitivity analysis studies, no quantitative framework, accurate CO2-EGR modeling, or design process has been identified. Thus, this work aimed to provide a practical screening tool to manage and predict the efficiency of enhanced gas recovery and CO2 sequestration in shale reservoirs. To meet our objectives, we performed correlation analysis to identify the strength of the relationship between the examined shale properties and engineering design parameters and the efficiency of CO2-EGR. Data for this study was gathered across publications on a wide subset of numerical modeling studies and experimental investigations. The sensitivity of data was further improved by a hybrid approach adopted for handling the missing values to avoid bias in our data set. Our results indicate that CO2 flooding might be the best applicable option for CO2 injection in shale reservoirs, whereas the huff-and-puff scenario does not seem to be a viable option. The efficiency of CO2-EGR increases as the pressure difference between injection pressure and reservoir pressure increases. The results show that shallow shale reservoirs with high fracture permeability, total organic content, and CO2-CH4 preferential adsorption capacity are favorable targets for CO2-EGR. Moreover, our results indicate that a successful hydraulic-fracture network with effective values of fracture permeability and conductivity is essential for a higher CO2-EGR efficiency. Well spacing and fracture half-length are crucial engineering features in CO2-EGR process design that must be carefully optimized due to their negative effect on CH4 production and positive effect on CO2 storage. Our statistical analysis lays a foundation for efficient CO2-EGR design and implementation and presents an important contribution to the field of reaching the target of net-zero CO2 emissions for energy transitions.

The offshore oil and gas working environment is an inherently dangerous one, with risks posed to physical safety on a daily basis. One neglected field of research is the added psychosocial stressors present in this environment. This research examined the experiences of offshore oil and gas workers through one-on-one online interviews which were recorded and transcribed. Transcripts were analyzed through the qualitative software NVivo, which generated themes and patterns for the responses given to questions that were developed through a focus group. The results of the analysis showed that multiple psychosocial stressors are present in this population, such as fear of speaking up, unsatisfactory company-provided facilities, work–life interference, work status, micromanaging, gender harassment and bullying. In addition, interviews identified that production and time pressures, along with fatigue, can influence accidents and mistakes. Climate factors also cause discomfort. However, these are managed according to best practices by organizations. Due to the timing of the study, COVID-19 was a significant stressor for some, but not all, employees. In conclusion, offshore oil and gas workers face multiple stressors in a dangerous environment that may lead to devastating consequences.

Background and aimsFatty streaks initiating the formation of atheromatous plaque appear in the tunica intima. The tunica media is not known to be a nidus for lipid accumulation initiating atherogenesis. We assessed changes to the tunica media in response to a micro-injury produced in the pig aorta. In addition, we assessed human carotid endarterectomy plaques for indication of atheroma initiation in the tunica media.MethodsThree healthy landrace female pigs underwent laparotomy to inject autologous blood and create micro-hematomas at 6 sites within the tunica media of the infrarenal abdominal aorta. These pigs were fed a high-fat diet (HFD) for 4–12 weeks. Post-mortem aortas from all pigs, including a control group of healthy pigs, were serially stained to detect lipid deposits, vasa vasora (VV), immune cell infiltration and inflammatory markers, as well as changes to the vascular smooth muscle cell (vSMC) compartment. Moreover, 25 human carotid endarterectomy (CEA) specimens were evaluated for their lipid composition in the tunica media and intima.ResultsHigh lipid clusters, VV density, and immune cell infiltrates were consistently observed at 5 out of 6 injection sites under prolonged hyperlipidemia. The hyperlipidemic diet also affected the vSMC compartment in the tunica media adjacent to the tunica adventitia, which correlated with VV invasion and immune cell infiltration. Analysis of human carotid specimens post-CEA indicated that 32% of patients had significantly greater atheroma in the tunica media than in the arterial intima.ConclusionThe arterial intima is not the only site for atherosclerosis initiation. We show that injury to the media can trigger atherogenesis.

This qualitative study was conducted with the aim of identifying psychosocial hazards in Australian offshore oil and gas facilities. Twenty-nine offshore oil and gas workers were interviewed via video link. Results indicated that, apart from the presence of a high-risk work environment as a source of mental and physical strain, there are organisational-specific stressors that cause workers' significant distress. Research results from NVivo analysis revealed that casualisation of the workforce was a major psychosocial hazard for offshore oil and gas workers, which resulted in feelings of insecurity, vulnerability and disconnection from work teams. In addition, a lack of stable income, an absence of opportunities to plan for the future and unsettled living arrangements worsen an already precarious existence. Findings show that a culture of blame and fear persists in some organisations, along with a lack of accountability and fear of making mistakes. The process of hiring, firing and rehiring was found to be a common practice by organisations in order to avoid their duty under the Fair Work Act amendments to offer casual conversion to their employees. Findings can be used to help inform organisational policies and assist in the development of risk control measures to minimise psychosocial hazards for offshore workers.

Adsorbed gas plays a key role in organic-rich shale gas production due to its potential to contribute up to 60% of the total gas production. The amount of gas potentially adsorbed on organic-rich shale is controlled by thermal maturity, total organic content (TOC), and reservoir pressure. Whilst those factors have been extensively studied in literature, the factors governing desorption behaviour have not been elucidated, presenting a substantial impediment in managing and predicting the performance of shale gas reservoirs. Therefore, in this paper, a simulation study was carried out to examine the effect of reservoir depth and TOC on the contribution of adsorbed gas to shale gas production. The multi-porosity and multi-permeability model, hydraulic fractures, and local grid refinements were incorporated in the numerical modelling to simulate gas storage and transient behaviour within matrix and fracture regions. The model was then calibrated using core data analysis from literature for Barnett shales. Sensitivity analysis was performed on a range of reservoir depth and TOC to quantify and investigate the contribution of adsorbed gas to total gas production. The simulation results show the contribution of adsorbed gas to shale gas production decreases with increasing reservoir depth regardless of TOC. In contrast, the contribution increases with increasing TOC. However, the impact of TOC on the contribution of adsorbed gas production becomes minor with increasing reservoir depth (pressure). Moreover, the results suggest that adsorbed gas may contribute up to 26% of the total gas production in shallow (below 4,000 feet) shale plays. These study findings highlight the importance of Langmuir isothermal behaviour in shallow shale plays and enhance understanding of desorption behaviour in shale reservoirs; they offer significant contributions to reaching the target of net-zero CO 2 emissions for energy transitions by exhibiting insights in the application of enhanced shale gas recovery and CO 2 sequestration — in particular, the simulation results suggest that CO 2 injection into shallow shale reservoirs rich in TOC, would give a much better performance to unlock the adsorbed gas and sequestrate CO 2 compared to deep shales.

Mono ethylene glycol (MEG) is highly utilized during gas production to mitigate hydrate formation issue. However, exposing the MEG to reboiler higher temperatures during distillation will lead to the reduced hydrate inhibition performance of the MEG due to thermal degradation and accumulation of organic acids such as glycolic, acetic and formic acids. The hydrate inhibition performance of the thermally degraded MEG was measured isobarically for pure methane gas using a cryogenic sapphire cell for the pressure ranges of 5500 to 20500 kPa. The objective is to determine and optimize the thermodynamic hydrate inhibition performance of thermally degraded MEG influenced by reboiler operation and MEG concentration in the lean MEG product. This research determines that operating the reboiler at high MEG concentration of 80.8 vol % for longer durations of 6.0 h raises the dissociation temperature by an average of 1.4 degrees C compared to 0.9 degrees C for the lower MEG concentration of 40.2 vol % for similar duration of 6.0 h. This suggests that lower MEG concentration will yield lower dissociation temperatures at the same retention time. Hence, the MEG thermodynamic inhibition performance is optimal at lower MEG concentration which results in lower dissociation temperature.

Background and Aims: It is unclear why sudden haemorrhage occurs in early atherosclerotic plaques, and whether an injury to the medial layer of the artery through wall movement and strain can initiate atherosclerosis. Hypothesis: Atheroma initiation (atherogenesis) may be triggered by a fatiguing motion from pulse pressure injury to the medial layer of the arterial wall leading to lipid deposition from vasa vasora. Aim: To initiate atherogenesis by establishing injury to the medial layer of the abdominal aorta.Methods: Three healthy landrace, female pigs (aged 9-10 weeks) underwent laparotomy to inject autologous blood or saline at 11-15 sites along the lower abdominal aortic wall. Pigs received either high fat diet (HFD) for 12 weeks (throughout the whole experiment) or four weeks only. Aortas from laparotomised and control healthy pigs were serially-stained for multiple markers and analysed using 3DHistech SlideViewer and HistoQuant software.Results: Injection of blood or saline induced injury within the medial layer of the arterial wall, leading to lipid cluster formation, not observed in non-injected sites. The sites of trauma also showed high density of vasa vasora and inflammatory cells, and rearrangement of vascular smooth muscle cells. The intimal layer of the artery remained unaffected by the injury. These outcomes were most prominent in the hyperlipidaemic pig fed with HFD for 12 weeks.Conclusions: We demonstrate that vascular trauma within the medial layer of the artery can trigger atherogenesis. The presence of vasa vasora in the injury sites suggests haemorrhagic sites can potentially occur at an early stage of atherosclerosis. Background and Aims: It is unclear why sudden haemorrhage occurs in early atherosclerotic plaques, and whether an injury to the medial layer of the artery through wall movement and strain can initiate atherosclerosis. Hypothesis: Atheroma initiation (atherogenesis) may be triggered by a fatiguing motion from pulse pressure injury to the medial layer of the arterial wall leading to lipid deposition from vasa vasora. Aim: To initiate atherogenesis by establishing injury to the medial layer of the abdominal aorta. Methods: Three healthy landrace, female pigs (aged 9-10 weeks) underwent laparotomy to inject autologous blood or saline at 11-15 sites along the lower abdominal aortic wall. Pigs received either high fat diet (HFD) for 12 weeks (throughout the whole experiment) or four weeks only. Aortas from laparotomised and control healthy pigs were serially-stained for multiple markers and analysed using 3DHistech SlideViewer and HistoQuant software. Results: Injection of blood or saline induced injury within the medial layer of the arterial wall, leading to lipid cluster formation, not observed in non-injected sites. The sites of trauma also showed high density of vasa vasora and inflammatory cells, and rearrangement of vascular smooth muscle cells. The intimal layer of the artery remained unaffected by the injury. These outcomes were most prominent in the hyperlipidaemic pig fed with HFD for 12 weeks. Conclusions: We demonstrate that vascular trauma within the medial layer of the artery can trigger atherogenesis. The presence of vasa vasora in the injury sites suggests haemorrhagic sites can potentially occur at an early stage of atherosclerosis.

This paper investigates the possible failure modes of an incident of ultrasonic (UT) pig lodged in a Corrosion Resistant Alloy (CRA) clad pipeline during a baseline in-line inspection as part of pre-commissioning pipeline activities. The paper establishes the pipeline integrity following the incident and determines whether it remains fit for the intended service. The paper also discusses the suitability of using UT pigging for in-line re-inspection of the damaged pipeline, the effect of hoop stress due to pipe-wall thinning and the possibility of crack growth. Additionally, the possibility of undetected damage is considered alongside rigorous fatigue crack growth and fracture mechanics assessments of the pipeline to ascertain the pipeline integrity. It was concluded that the probability of the pipeline sustaining flaws exceeding a minimum depth of 1.8 mm is minimal. Due to the robust manufacturing process of the CRA clad pipeline, it was also concluded that the gouges left during the pigging incident do not affect the ability of the clad layer to provide corrosion protection.

This paper describes an incident that occurred during the baseline inspections of pre-commissioning activities performed on a 20-in. metallurgically bonded corrosion resistant alloy (CRA) clad pipeline of an approximate length equal to 2.7 km. The inspection tool, deployed as part of the baseline inspections before the startup of the pipeline, was damaged in the CRA clad pipeline. This damage occurred despite extensive computer simulations, carried out before the inspection, which indicated that the tool, an ultrasonic (UT) pig, was able to traverse the length of the pipe without major issues. The application of the pressure surges was successful in dislodging the UT pig; however, as a direct consequence, the UT pig crashed into the pig receiver and sustained significant damage. The sealing pigs that were trailing behind the UT pig also collided with the rear of the UT pig, and it was at this junction that all further data transmission was ceased. A metal swarf was discovered upon inspection of the UT pig after retrieval, indicating that the inner wall of the pipeline also sustained damage. An analysis of the swarf indicated that it comprised solely of the CRA alloy that was metallurgically bonded to the inner wall of the carbon steel pipe. It was concluded that, due to the anticorrosive nature of the CRA material and high-quality control standards upheld during the manufacture of CRA pipes, the baseline in-line and routine inspections were unnecessary and can be detrimental if the inspection tool becomes impacted, thereby compromising the containment of the CRA layer.

Reservoir heterogeneity reflected by permeability variation in the vertical direction is expected to significantly impact on the subsurface multiphase flow behaviour. In this context, we have shown previously that during immiscible flooding the crossflow between low and high permeability zones plays a significant role in determining the reservoir performance in terms of the hydrocarbon yield. In this manuscript, the contribution of crossflow to oil recovery in layered sandstone porous media during miscible CO2 flooding is explored. We conducted core flooding experiments using a core sample constructed by attaching two axially split half sandstone plugs each with a different permeability (0.008 and 0.1 (μm)2). The crossflow between the two layers was controlled by placing either a lint-free tissue paper or an impermeable Teflon sheet to represent a layered heterogeneity with and without communication, respectively. Additionally, to better understand the underpinning mechanisms influencing the flood performance, we imaged the samples during flooding using a high-resolution medical X-Ray computed tomography (XCT) scanner. Our results show that core-scale heterogeneity would indeed play an important role in determining the spatial distribution of the injected CO2during miscible flooding, consequently the oil recovery factor. For instance, our results confirm that permeability heterogeneity in vertical direction would lead to CO2 establishing a prefrential flow path through the high permeability layer leading to its early breakthrough. The above-mentioned CO2 channeling is clearly evident from the X-ray images captured during flooding. However, a reasonble amount of CO2 would still enter the low permeability layer contributing positively to the ultimate oil recovery factor. In fact, the post-processing of the XCT data confirmed the above to take place when cross-layer communication was allowed. The diversion of CO2 from the high to low permeablity layer is believed to be due to the crossflow phenomenon (induced by the viscous and dispersion forces) resulting in a subtle increase (i.e. 1.7%) in the ultimate oil recovery. In a similar study we have done about immiscible flooding, the contribution of crossflow to the overall recovery was found to be about 5%. The less pronounced effect of crossflow under miscible conditions is believed to be due to the absence of capillarity as a more effective driving force behind crossflow. To the best of our knowledge, our core-flooding results as presented in this manuscript and backed by X-ray CT visualisation, are the first set of their kind. They are insightful and would be of interest to the scientific community in revealing how crossflow may control flow behaviour in heterogeneous sandstone reservoirs, with important implications for numerical modelling of CO2 injection.

Understanding wettability of clay minerals is crucial in assessing primary migration of hydrocarbon and evaluating CO2 storage capacities and containment security. In spite of recent efforts, there is considerable uncertainty of experimental data and theoretical predictions are lacking. We, therefore, developed new correlations to predict the advancing and receding contact angles of three different clay minerals (i.e., montmorillonite, Illite and kaolinite) as a function of gas density. To do so, we first measured clay minerals advancing and receding contact angles for helium, nitrogen, argon and carbon dioxide/brine systems at various pressures (5, 10, 15 and 20 MPa) and a constant temperature of 333 K. The statistical analysis shows that the developed correlations are capable of predicting the contact angles of the three clay minerals with very high accuracy (i.e., R > 0.95, for all the newly developed correlations). We thus conclude that the wettability of these clay minerals can be computed from knowledge of the gas densities, using these new empirical correlations. This work has important implications for improving wettability predictions, and thus reducing risks related to subsurface operations, such as CO2 storage or hydrocarbon recovery. (c) 2021 Society of Chemical Industry and John Wiley & Sons, Ltd.

Mono ethylene glycol (MEG) has been used as a thermodynamic hydrate inhibitor in the gas industry. Due to its high usage, recoverability and environmental impact, MEG is regenerated instead of releasing to the environment. During the regeneration (distillation) process, MEG is exposed to higher temperatures in the reboiler to remove surplus water. When exposed to high temperatures, MEG thermal degradation process can occur due to dissociation to organic acids including glycolic, acetic and formic acids. A batch distillation system was utilised in total reflux mode at different reboiler temperatures retention times for up to 18 h in a span of 3 h and MEG concentrations of 80.8, 70.3, 63.1, 51.0 and 40.2 vol percentage (vol %) with corresponding reboiler testing temperatures of 118.0, 113.2, 108.8, 104.2 and 102.5 degrees C, respectively. The objective of this experimental work focuses on determining the MEG degradation products i.e. organic acids, accumulation in the MEG regeneration system. The degradation products were analysed using Ion Chromatography (IC) technique at the Curtin Corrosion Centre (CCC) laboratory, Perth, Western Australia. The experimental results indicate that there is an increasing trend of the MEG degradation products at higher boiling point temperatures for higher MEG concentrations in comparison to the lower MEG concentrations. Moreover, organic acids accumulation in the reboiler was evident at longer reboiler retention time durations of 18 h. The findings of this study conclude that it is preferable to operate the reboiler at lower MEG concentrations levels of 40.2 vol % and at reboiler retention time of 3 h to decrease the likelihood of the MEG degradation products. The percentage increase of the total organic acids at 40.2 vol % was found to be 27.7% as compared to 32.6% at 80.8 vol %. This study is beneficial to the oil and gas industry as it proposes the percentage amount of MEG to be used for hydrate inhibition in order to minimize the production of organic acids. High levels of organic acids accumulation in the regenerated lean lowers the efficiency of MEG thermodynamic inhibition performance.

Knowledge of the properties of reservoir fluids are very important in petroleum reservoir engineering (e.g. estimation of reserves in an oil reservoir, well test inflow performance calculations, and numerical reservoir simulation). The process of obtaining accurate values for these physical properties for hydrocarbon is most important in different oil industries. The main resource to get these properties is laboratory measurements but in many cases these measurements not available, thus other methods can be used to estimate these properties. This paper concerns with the prediction of the phase behavior and physical properties for a Middle Eastern sandstone reservoir by using multiphase equilibrium and properties determination program. Soave-Redlich-Kwong Equation of State & Peng-Robinson’s Equation of State and its modifications have been used to calculate the physical properties of reservoir fluid. To do so, each laboratory experiment was first simulated with the cubic Peng Robinson EOS without performing any regression and compared to the laboratory observations (PVT) as primarily results. Then splitting and lumping processes were used to tune or characterize the EOS so that it can reproduce the PVT experiments. The calculated PVT properties from these two steps are compared with the measured PVT data and the results show that the splitting and lumping processes given a good accuracy in predicting the PVT properties of the sandstone reservoir.