International Journal of Oil, Gas and Coal Technology (19 papers in press)

Regular Issues

• Painting India’s hydrogen green  
  by Usha Shukla 
  Abstract: With an increased focus on sustainability and clean energy, the field of green hydrogen provides new opportunities and scope to deal with the current problem of carbon emission. Green hydrogen due to its versatile nature and myriad applications can serve as an alternative to the existing menace of fossil fuels. The present paper aims to provide insights in the realm of green hydrogen and focuses on the initiatives that India has taken to transform itself into a global hub of generation green hydrogen and fulfilling its futuristic demand of green hydrogen. [Received: November 4, 2023; Accepted: March 25, 2024]
  Keywords: green hydrogen; solar energy; fossil fuels; myriad applications; India’s Panchamrit; Green Hydrogen Odyssey; India.
  
  
• A new method for predicting the failure pressure of locally corroded oil and gas pipelines  
  by Ziyan Feng, Mingwei Cui 
  Abstract: The increasing number of aging oil and gas gathering pipelines in China has significantly increased pipeline failure accidents due to local corrosion. However, so far no method was especially geared to calculating the failure pressure of locally corroded pipeline. This paper validated the reliability of nonlinear finite element method to assessing locally corroded pipeline. It has respectively investigated the effects of local corrosion morphology, corrosion radius, and corrosion depth on pipeline axial and hoop stress, failure position and failure pressure. Referring to stress concentration theory, meanwhile, combined with numerical simulation, this paper has established a new method for calculating the failure pressure of locally corroded pipeline, and comparing with B32G (modified), DNV-RP-F101, and recently developed method PCORRC this method has small and even distributed errors, and can meet the demand of predicting the failure pressure of locally corroded pipeline. [Received: March 2, 2023; Accepted: March 25, 2024]
  Keywords: oil and gas pipeline; local corrosion; corrosion morphology; corrosion dimension; nonlinear finite element method; calculation method.
  
  
• Evolutionary algorithms for integrated oil and gas supply chain management considering enhanced oil recovery methods  
  by Raheleh Ardestani, Esmaeil Mehdizadeh, Farhad Etebari 
  Abstract: The aim of this study is to model and solve the problem of integrated oil and gas supply chain management (SCM) considering the enhanced oil recovery (EOR) methods in upstream and midstream sectors. For this purpose, the problem is modelled as a bi-objective mixed integer nonlinear program and solved by using BARON solver in the GAMS software. The LP-metric method is used to solve the bi-objective problem. In addition, we used three evolutionary algorithms, namely non-dominated sorting genetic algorithm (NSGAII), multi-objective whale optimisation algorithm (MOWOA), and multi-objective cuckoo search algorithm (MOCSA) to solve the problems of large sizes. To investigate the efficiency of the solution method, 15 problems were solved with a wide range of dimensions. Based on the results, small-size problems can be solved in less than 100 seconds to reach a relative gap of 0.01. However, the solution time increases rapidly when the size of the problem increases. The results of the evolutionary algorithms show that these algorithms (especially MOWOA) can solve the large problems in a reasonable time. In addition, MOWOA is superior to other implemented algorithms in terms of multi-objective solution quality measures. [Received: March 3, 2023; Accepted: October 27, 2023]
  Keywords: oil; gas; supply chain management; SCM; enhanced oil recovery; multi-objective; whale optimisation; NSGAII; cuckoo search.
  
  
• Effects of methanol substitution rate on combustion and emission characteristics of methanol/diesel dual fuel engines  
  by Changchun Xu, Huabing Wen, Haiguo Jing, Jingrui Li, HaengMuk Cho, Daifen Chen 
  Abstract: In order to investigate how methanol affects combustion and emission, this article tries to alter the ratio of substitution of methanol. The methanol replacement rate is set as 0%, 10%, 20%, 30%, 40% for researching engine combustion performance and exhaust emissions. The results indicate that, under medium and low load circumstances, the maximum burst pressure in the cylinder falls, the ignition delay lengthens, and the general consumption of energy increases as the methanol substitution rate increases. HC and CO emissions exhibited an increase, whereas NOx emissions demonstrated a decrease. Under high load conditions, the maximum explosion pressure initially rose and subsequently declined. Additionally, the total energy consumption displayed an initial decreasing trend followed by an increasing trend. HC and CO emissions experienced a slight increase, while NOx levels remained relatively stable before eventually decreasing. [Received: January 17, 2024; Accepted: April 1, 2024]
  Keywords: methanol substitution ratio; high latent heat of vaporisation; combined injection; performance; exhaust emissions.
  
  
• Analysis of the effect of different pretreatment conditions on pore structure heterogeneity of low-rank coal based on multifractal theory  
  by Lirong Gao, Teng Li, Jiao Peng, Jianzhong Zhang 
  Abstract: In order to select the pretreatment conditions of low-temperature nitrogen adsorption experiment more scientifically, low-temperature gas adsorption experiments of five particle-size subsamples pretreated at seven degassing temperatures were conducted. The results showed that the higher the degassing temperature, the faster the volatile and water separated, and some of pores collapsed. After mechanical crushing, some pores are filled and blocked by mineral particles. Multifractal analysis shows that the pore connectivity hardly improves with increasing degassing temperature, while the heterogeneity of pore distribution is enhanced. With the decrease of particle size, the heterogeneity of pore size distribution decreases, while the connectivity of pores increases. With the increase of degassing temperature or the decrease of particle size, nitrogen adsorption capacity, sample mass, pore volume and pore area all showed a three-stage decline. Ultimately, 120 C and 40-60 mesh are recommended as the best degassing temperature and sample size for low-temperature gas adsorption method. [Received: 24 February 2023; Accepted: 14 April 2024]
  Keywords: pretreatment temperature; particle size effect; pore structure; multifractal analysis; low rank coal.
  
  
• Research on reservoir quality characterisation methods for tight sandstone reservoirs - a case study of the Southern Ordos Basin  
  by Min Zou, Dongling Xia, Dongdong Xia, Linlin Wang 
  Abstract: A integrating innovation method, carrying three steps, was proposed to characterise reservoir quality distribution and select sweet spots in tight sandstone reservoir. Firstly, at the microscale, starting from the characteristics of micro-pore throats, the fundamental differences in reservoir quality due to variations in micro-pore structure are examined, establishing the relationship between different pore-throat combinations and reservoir quality. Secondly, at the mid-scale, based on the characteristics of reservoir structure at the single well level, three reservoir structure styles are proposed, and the degrees of diagenetic modification was inspected with each structure, clarifying the distribution characteristics of high-quality reservoirs within different reservoir structure. Finally, at the macroscale, starting from sedimentary differences, the impacts of differences in sedimentary scale and sedimentary clastic composition on reservoir structure types and diagenetic types are identified, thereby controlling the spatial distribution of reservoir quality. Based on these steps, a comprehensive reservoir quality characterisation method, constrained by both sedimentation and diagenesis, is developed. [Received: 19 January 2024; Accepted: 15 March 2024]
  Keywords: characterisation methods; reservoir quality; tight sandstone; Ordos Basin.
  
  
• Biodiesel production from third-generation feedstock: process parameter modelling and optimisation using RSM-ANN approach  
  by Aqeel Ahmad, Ashok Kumar Yadav, Shifa Hasan 
  Abstract: This study employed response surface methodology (RSM) coupled with a central composite design (CCD) approach to ascertain the optimal conditions for biodiesel production from Neochloris oleoabundans microalgae oil. Four key process variables, including the methanol-to-oil molar ratio, catalyst concentration, reaction time, and temperature, were investigated across five levels to develop an L30 orthogonal array for experimentation. An artificial neural network (ANN)-based prediction model was developed using the experimentally obtained data, yielding high accuracy with mean square error (MSE) values of 0.019, 2.4327, and 0.8269 and coefficient of determination (R2 ) values of 0.9996, 0.9796, and 0.9890 for training, validation, and testing sets, respectively, indicating robust predictive capability. The optimisation analysis reveals a biodiesel yield of 94.94% under optimised conditions: 6.92:1 molar ratio, 1.22% catalyst concentration, 64.36 min reaction time, and 56.46 C temperature. Experimental validation confirmed the reliability of the optimisation results, demonstrating a marginal error of 2%. [Received: November 25, 2022; Accepted: April 30, 2024]
  Keywords: biodiesel production; Neochloris oleoabundans; response surface methodology; RSM; artificial neural network; ANN; sustainable fuel; central composite design; CCD; mean square error; MSE.
  
  
• Experimental study on prediction of gas pressure variation during coal and gas outburst  
  by Erhui Zhang, Xukai Dong, Baokun Zhou, Lei Yang 
  Abstract: To accurately predict the variation of gas pressure during the coal and gas outburst experiment, a gas pressure prediction model was established based on Keras and long short-term memory (LSTM). Meanwhile, the ARMA and ARIMA models were selected for comparative analysis. The findings reveal that the ARMA model exhibits the shortest prediction time, but its RMSE and MAE values are the largest, suggesting that the ARMA model yields the poorest predictive performance. The LSTM model achieved the lowest RMSE, and its MAE closely approached that of ARIMA, but the ARIMA model could only predict the gas pressure in the short term. Therefore, it can be employed as the prediction model for gas pressure in coal and gas outburst experiments. The research findings offer significant auxiliary support for predicting the change of gas pressure during coal and gas outbursts, thereby facilitating further prediction and prevention of such occurrences. [Received: October 9, 2023; Accepted: February 27, 2024]
  Keywords: coal and gas outburst; gas pressure prediction; LSTM neural network; multistep prediction.
  
  
• Application of pigging track approach in gas-exhausting for gas-liquid two-phase flow in undulating pipelines  
  by Sihang Chen, Gong Jing, Yang Qi 
  Abstract: During the gas-liquid replacement process of the oil undulating pipeline, there are liquid single-phase parts, gas single-phase parts and liquid gas two phase parts appearing alternately, which pose challenges to the pig tracking and gas-exhaust simulation. In this paper, a novel approach to exhaust the gas from the pipe applying the pigging tech is proposed, and the complicated motion of pig in the undulating pipeline is described by the self adapting momentum equations based on the hydraulic analysis during operation process. The analysis focus on the changeable pressure and force condition happen to the pig with its moving along the pipeline, and switch the describe-equation to the pigs automatically. The model validation by the field data of a real pipeline in China shows that the relative deviation of pig real time speed is within 0.5%, and the relative deviation of pig position is within 2.2%. [Received: October 11, 2023; Accepted: March 7, 2024]
  Keywords: pigging process; undulating pipelines; gas-liquid two-phase flow; pig-tracking; gas exhausting.
  
  
• Paleoenvironment and petroleum potential of the lacustrine shales in the Lower Cretaceous Shahezi Formation of the Southern Songliao Basin, NE China  
  by Zhengjian Xu, Shu Jiang, Xiaodong Hu, Wenchao Zhang, Xiaogang Li, Shaohua Xu, Nini Zhang 
  Abstract: The occurrence of conventional and unconventional hydrocarbons is directly determined by organic matter (OM)-rich shales in fault-controlled sedimentary basins. Through integrated analyses of organic petrology, element concentrations, bulk organic geochemical characteristics, hydrocarbon generation, and expulsion of the Shahezi shales, we have conducted comprehensive studies on the paleoenvironment, OM source, and petroleum potential of the Shahezi shales: 1) the Shahezi deposition occurred under a cold and semi-humid to semi-arid paleoclimate, and sub-reducing to reducing redox conditions, favourable for OM preservation; 2) the OM origins of shales are primarily a mixture of aquatic microorganisms and terrestrial higher plants; 3) the shales demonstrate a fair to excellent source rock potential; 4) oil generation began around 130 Ma, while gas generation started around 105 Ma; 5) the shales have reached the hydrocarbon expulsion threshold; 6) the occurrence of burial-deep tight gas reservoirs, is predominantly controlled by the outer boundary of the shale distribution. [Received: December 29, 2023; Accepted: January 24, 2024]
  Keywords: lacustrine shale; paleoenvironment; organic matter origin; petroleum potential; Shahezi Formation; Southern Songliao Basin; China.
  DOI: 10.1504/IJOGCT.2024.10063872
   
  
• Effect of a vortex plate on turbulent flow within an axial hydrocyclone for preliminary water separation  
  by Meili Liu, Pingping Qiao, Zhengrui Hu, Yaoyuan Zhang, Jiaqing Chen 
  Abstract: The conflict between separation efficiency and pressure drop has emerged as a key factor affecting the widespread adoption and application of hydrocyclones for preliminary water separation. This study presents a novel approach to enhance hydrocyclone performance by leveraging turbulent coherent structures. Specifically, a vortex plate, designed to interfere with turbulence-coherent structures was placed within the blade region, and its impact on the hydrocyclone's flow field was thoroughly investigated through numerical simulations. The findings reveal that this method selectively alters the turbulent micro-flow field, reducing drag losses without affecting the macro time-averaged flow field. Consequently, it successfully addresses the inherent conflict between separation efficiency and pressure drop. An appropriately positioned vortex plate exhibited remarkable outcomes, including a significant 74% reduction in the offset distance of the vortex centre, a 1.56% increase in water separation efficiency, a 12.68% reduction in the oil concentration of the heavy phase outlet, and an 18.1% reduction in underflow pressure drop. These outcomes demonstrate the dual benefits of improving separation efficiency and minimising energy loss, underlining the potential of this approach for optimising hydrocyclone performance. [Received: December 2, 2023; Accepted: February 3, 2024]
  Keywords: hydrocyclone; vortex plate; separation efficiency; pressure drop.
  DOI: 10.1504/IJOGCT.2024.10063871
   
  
• Simulation study on frictional resistance and influencing factors of flexible screen pipe tripping into horizontal wellbore  
  by Zhongzhi Hu, Junliang Li, Li Wang, Jinbo Wang, Xinyang Liu, Yang Kong 
  Abstract: Flexible sand control screens play a crucial role in the operation and economic benefits of ultra-short radius wells. We established a calculation model for the motion friction resistance of flexible screens and a criterion for contact between screen units and wellbore walls. Case analysis clarified the correlation between several key factors (e.g., maximum allowed swing angle, friction coefficient, insertion speed, and total length of screen units) and the frictional resistance of flexible screens. We utilised the overall distribution of contact point positions and the compressed distance between adjacent screen unit centroids to analyse the conversion mechanism of screen friction resistance from linear to nonlinear rapid accumulation. We also explored measures to improve the extension capacity of flexible screens. Our findings provide a basis for the optimisation design of flexible screen structures and the assessment of their maximum extension capacity. [Received: June 2, 2023; Accepted: February 13, 2024]
  Keywords: flexible screen; sand control; multi-body dynamics simulation; frictional resistance.
  DOI: 10.1504/IJOGCT.2024.10063870
   
  
• Lithofacies identification and prediction of Chang 7₃ shale oil reservoirs in Ordos Basin: insights from the multi-resolution graph-based clustering analysis  
  by Ruiliang Guo, Junhong Jia, Guangjun Xu, Fei Liu, Jingzhou Zhao, Yubin Bai, Weitao Wu, Lei Cao 
  Abstract: The Chang 7 member of Yanchang formation of the Ordos Basin contains abundant shale oil resources, making it the core area for exploration and exploitation of lacustrine shale oil in China recent years. However, the strong spatial heterogeneity makes lithofacies identification and prediction a key challenge in shale oil reservoir development. This study divides the lithofacies of the Chang 7₃ shale oil reservoir into four types based on sedimentary structure, mineral composition, and TOC content, namely high TOC tuffaceous laminated shale, high TOC argillaceous laminated shale, moderate TOC felsic laminated shale, and moderate TOC felsic bedded mudstone. Multi-resolution graph-based clustering analysis (MRGC) was used to perform cluster analysis on lithofacies sensitive logging, including GR, AC, DEN, RT, and SH, and the electrofaices was compared with single well lithofacies to establish the logging value range model for different lithofacies.. This study validates the applicability of MRGC in shale lithofacies division and rapid prediction. [Received: January 4, 2024; Accepted: February 13, 2024]
  Keywords: Ordos Basin; Yanchang formation; shale oil; lithofacies; MRGC.
  DOI: 10.1504/IJOGCT.2024.10063873
   
  
• A new methodology for optimising production in an integrated model using a genetic algorithm  
  by Mehdi Fadaei, Mohammad Javad Ameri, Yousef Rafiei 
  Abstract: Optimisation of the production of an integrated model is the best method to increase production from hydrocarbon reservoirs. Constraint optimisation of an integrated model using a genetic algorithm can optimise and govern production. This paper presents a novel method for optimising integrated production systems. The novel approach is constraint optimisation with a genetic algorithm. The elements of the integrated model are the reservoir, well, choke, pipeline, and separator. One of the essential issues in integrated modelling is evaluating flow regimes before surface equipment. The target function of this study is maximising oil in the stock tank. The constraint for optimisation approaches is that no slug flow regime has formed at the separator inlet. The optimisation integrated model with the genetic algorithm increases the oil in the stock tank by about 16%. [Received: March 6, 2023; Accepted: February 13, 2024]
  Keywords: new; optimising; production; integrated; genetic; algorithm.
  DOI: 10.1504/IJOGCT.2024.10063869
   
  
• Thermo-hydro-mechanical-damage coupling mechanism and failure behaviour of caprock in SAGD operations  
  by Haijing Wang, Chao Zhang, Bo Zhou, Shifeng Xue, Peng Jia, Xiuxing Zhu 
  Abstract: A coupled thermo-hydro-mechanical-damage model considering anisotropic stiffness degradation of rock after shear damage is developed for the first time, and the coupling mechanism and failure behaviour of caprock in steam assisted gravity drainage (SAGD) operations are systematically investigated using analytical and numerical approaches. New insights into the failure characteristics of caprock were obtained. The damage of caprock is mostly induced by shear and initiates near the interface directly opposite the well pair in the earliest stage of SAGD production and propagates rapidly to form a main crack. The vertical and zigzag main crack may penetrate the caprock, while the secondary cracks on both sides are mostly inclined and straight that they cannot penetrate the caprock. Failure modes of caprock are observed including penetrating crack, non-penetrating crack and interface damage. This study will be helpful in accurately evaluating the caprock integrity and efficiently breaking interbedded shale or mudstone layers in thermal recovery reservoirs. [Received: June 2, 2023; Accepted: February 13, 2024]
  Keywords: thermo-hydro-mechanical-damage; THMD; analytical analysis; numerical simulation; caprock failure; steam assisted gravity drainage; SAGD.
  DOI: 10.1504/IJOGCT.2024.10064675
   
  
• Fatigue failure analysis based on coupling vibration of drill string in ultra-deep wells  
  by Guojie Cui, Hongshan Zhao, Runfeng Cai, Donghong Guo, Sheng Zhong, Wenchang Wang 
  Abstract: Fatigue failure of drill string occurs frequently in deep wells. However, the commonly used fatigue ratio is difficult to evaluate drill string fatigue safety accurately. In this paper, considering the characteristics of super slenderness ratio of drill string and collision with the wellbore wall, the coupling vibration of drill string is studied, and the vortex characteristics and dynamic stress of the drill string are calculated more accurately. On this basis, combined with the calculation method of fatigue coefficient under asymmetric variable stress amplitude, the strength criterion of fatigue failure of drill string under dynamic condition is established. The results show that this method can better understand the working state of the drill string in the wellbore and predict the risk position of fatigue failure of whole drill string more accurately in vertical wells. [Received: March 28, 2023; Accepted: February 13, 2024]
  Keywords: drill string; coupled vibration; dynamic stress; fatigue failure.
  DOI: 10.1504/IJOGCT.2024.10064676
   
  
• Screening and performance evaluation of epoxy resin long-term sustained-release solid tracer  
  by Mingqiang Wei, Yuhong Wang, Yonggang Duan, Yan Li, Yihe Du 
  Abstract: This study selects suitable epoxy resin as a sustained-release material. The sustained-release carrier was mixed with different water-soluble tracers to create a solid sustained-release tracer. The material's microstructure, compression performance, and thermal stability were characterised and analysed. Considering the stability and mechanical properties of the prepared solid spline, the single-factor experiment and a dynamic scouring test were carried out using epoxy resin B and a sodium bromide tracer. The single-factor experiment showed that tracer release increased with temperature and dosage and decreased with mineralisation. The highest release of sodium bromide tracer occurred at pH 7. The flow rate experiment indicated a positive correlation between the flow rate and the cumulative release rate of the tracer. The first-order kinetic equation is a dependable approach for elucidating the release phenomenon of the sustained-release solid tracer. The tracers provide a new way to synthesise long-term sustained-release solid tracers. [Received: January 4, 2024; Accepted: March 4, 2024]
  Keywords: epoxy resin; sustained-release material; sustained-release tracer; single-factor experiment; the first-order kinetic equation.
  DOI: 10.1504/IJOGCT.2024.10064677
   
  
• Influence mechanism of mining speed on energy release in a mine roof and elastic coal system  
  by Longfei Feng, Quan Zhang, Guangjian Liu 
  Abstract: Deep, high-stress, high-strength mining conditions will make the energy release from the mining fields more intensive. The influence mechanism of mining speed on energy release in the mining area was studied using elastic mechanics theory, numerical simulation, and on-site measurement methods. When the average mining speed increases from 3.68 m/d to 5.6 m/d, the cyclic weighting step distance increases from 29.5 m to 38.85 m, indicating that the faster the mining speed, the larger the periodic fracture size of the inferior key strata, and the more energy the bending and sinking static load and dynamic load input into the coal body, the easier to induce rock burst. Based on the curve of mining speed and high-energy mining earthquakes frequency, the critical safe mining speed of Hujiahe Coal Mine is determined to be 4.8 m/d. These conclusions can provide a basis for the mining intensity optimisation in rockburst mines. [Received: May 17, 2023; Accepted: February 27, 2024]
  Keywords: mining speed; static load potential energy; bending elastic energy; rock burst; mining intensity optimisation.
  DOI: 10.1504/IJOGCT.2024.10064678
   
  
• A comprehensive review: role of fuel injection methodologies on performance enhancement and mitigation of emissions in the diesel engine  
  by Krishnamani Selvaraj 
  Abstract: The compression ignition engines are extremely significant in the field of energy, transport, and agriculture owing to their reliability and efficiency. The engines, on the other hand, are a major source of greenhouse gases and toxic emissions. According to global emission guidelines for sustaining a healthy environment, the measures needed to decrease pollution are of utmost important. Recent developments in diesel engines, notably in the fuel injection system, have made it possible to achieve the required levels of controlled emissions. Adopting the right fuel injection techniques, which significantly improve combustion quality, has resulted in a potential improvement in engine performance with regulated emissions in diesel engines. Delivering the fuel with higher 'fuel injection pressure' into the combustion chamber could reduce the carbon monoxide and particulate emissions with minimum 'specific fuel consumption' but the approach is not effective in controlling oxides of nitrogen emissions. On the other hand, the other fuel injection techniques like pilot injection and 'split injection' with optimised 'injection timing' help in reducing NO_X emission from the engines with better power output. This review article focuses on a detailed study of various fuel injection techniques along with advantages for improving engine performance and reducing exhaust emissions. [Received: August 18, 2023; Accepted: November 17, 2023]
  Keywords: compression ignition engine; fuel injection pressure; FIP; electronic fuel injection; EFI; brake thermal efficiency; brake specific energy consumption; split/multiple injection; fuel injection timing; FIT.
  DOI: 10.1504/IJOGCT.2024.10064379