International Journal of Oil, Gas and Coal Technology (14 papers in press)

Regular Issues

• Simulation of SAGD for the greenfield development plan using AI-based parameter optimisations  
  by Vrutang M. Shah, Jainish Shinghala, Vivek Ramalingam 
  Abstract: Steam assisted gravity drainage is a widely-used technique; however, the high operating costs and water usage associated with this technique necessitate a thorough investigation and optimisation of sensitive parameters. The focus of this study is to develop and optimise the steam assisted gravity drainage process for developing a new field. The traditional steam assisted gravity drainage process is simulated alongside a mature strategy for a period of 16 years. The mature strategy employed in this study includes pressure tapering and the injection of non-condensable gas. The simulation results demonstrate that the non-condensable gas injection strategy is more economically effective than the traditional steam assisted gravity drainage process in the mature stage. Additionally, parametric optimisation studies performed on operating pressure, injection temperature, and steam quality to maximise the net present value of the block; indicate an increase in net present value from 20 million dollars to 30 million dollars, highlighting the significance of this optimisation study. [Received: 31 January 2023; Accepted: 11 June 2023]
  Keywords: steam-assisted gravity drainage; greenfield development plan; AI-based parameter optimisations; techno-economical evaluation; thermal enhanced oil recovery.
  DOI: 10.1504/IJOGCT.2023.10057685
   
  
• Effect of cyclic loading phenomenon on the crush resistance of different proppants: an experimental investigation  
  by Hari Sreenivasan, Dhrumil Patel, Shanker Krishna 
  Abstract: Frequent well shut-ins and production cycles associated with a hydraulic fracturing job affect proppant-packs’ behaviour within the fractures. In this study, 20/40 mesh-size range of four proppant type viz. sand, resin-coated sand (RCS), intermediate strength proppant (ISP) and high strength proppant (HSP), is examined under cyclic loading conditions. The load cycled between 50% of rated stress of each proppant type to the maximum value, and the numbers of cycles considered were 1, 3, 5 and 10. In the first cycle, the quantity of fines formed was 7.138%, 0.187%, 2.151% and 2.106% for sand, RCS, ISP and HSP, respectively. In the tenth cycle, the total fines further increased to 34.004%, 13.714%, 26.305% and 26.305%, respectively. In RCS, breaking down of larger proppants in terms of quantity per cycle is lesser as compared to sand, HSP and ISP. Formation of a thick cured bonding between the RCS particles plays a significant role. [Received: April 11, 2023; Accepted: June 11, 2023]
  Keywords: unconventional resources; oil and gas production; hydraulic fracturing; proppant packs; proppant crushing; proppant distribution.
  DOI: 10.1504/IJOGCT.2023.10057867
   
  
• Study on downloading contaminated product at an intermediate station in Lanzhou-Chengdu-Chongqing multi-product pipeline  
  by Qianqian Shao, Wang Li, Nuo Xu 
  Abstract: Lanzhou-Chengdu-Chongqing multi-product pipeline (LCY pipeline) is the first multi-product pipeline of large diameter and long transportation distance in China. This research aimed to propose a novel scheme of downloading contaminated product at an intermediate station of LCY pipeline. For this purpose, a new idea of combining Austin-Palfrey equation with OLGA simulation was employed, which considered the pipeline features and large amount of production data. Numerical model in OLGA was developed and modified based on pipeline information and production data. Contaminated volume variation in LCY pipeline was simulated against downloading different volumes at different intermediate stations. The feasibility of downloading contaminated product at an intermediate station was investigated. The optimal intermediate station and download volume were determined in economic terms. Chengdu station was found the optimal station by large superiority. The optimal download ratio was determined to around 60% among the total contaminated volume in LCY pipeline. [Received: April 11, 2023; Accepted: June 11, 2023]
  Keywords: multi-product pipeline; contaminated volume; equivalent length method; ELM; Austin-Palfrey empirical equation; numerical simulation.
  
  
• Rice straw biomass conversion into biochar as a potential solid fuel with high heating value using microwave vacuum pyrolysis technology  
  by Chanpreet Singh, Anoop Kumar Singh, Nitin Saluja 
  Abstract: The wide availability of biomass attracts the focus of researchers owing to the capability to convert it into the form of biofuel. Rice straw is one of the agricultural wastes that has been burned on farms in past years and requires an alternate solution to be converted into biochar. This work proposes an experimental validation that aids in the development of high-efficiency microwave vacuum pyrolysis (MVP) of biomass without exceeding a temperature limit of up to 600-700 C, preserving the yield of biochar. The straw waste is processed in the MVP at different microwave power ratings of 450, 600, and 750 W with a constant vacuum pressure of 0.03 MPa. The sample is analysed for thermogravimetric, proximate, ultimate analyses, and high heating value (HHV). The obtained results of biochar yield are 43, 40, and 37 wt.% with the HHV of 1416 MJ Kg1. [Received: 2 June 2023; Accepted: 21 June 2023]
  Keywords: microwave pyrolysis; vacuum; biomass waste; biochar yield; solid fuel; rice straw.
  DOI: 10.1504/IJOGCT.2023.10058306
   
  
• Mechanical characteristics and damage evaluation of coal subjected to aerodynamic cavitation: an experimental study  
  by Hu Wen, Bin Cheng, Siqing Sun, Duo Zhang, Bingyi Jia, Mingyang Liu 
  Abstract: Aerodynamic cavitation, employed as a method for preventing coal and gas outbursts, has produced good results in the Huainan mining area in China. In this study, unloading confining pressure triaxial compression experiments were utilised to evaluate the mechanical characteristics of coals subjected to this rapid unloading process. Aerodynamic cavitation was simulated using physical similarity experiments, and the gas injection pressure and pressure duration were utilised as variables to assess the damage in a coal seam caused by a gas injection-blowout event. According to the results, a gas injectionblowout event causes damage that extends to a depth of approximately 45 mm. The study reveals that the damage caused by aerodynamic cavitation depends on the pressure condition of the pores in the coal. This study provides a theoretical basis for increasing the cavitation effect caused by a gas injection-blowout event, simultaneously saving construction costs. [Received: March 29, 2023; Accepted: July 13, 2023]
  Keywords: aerodynamic cavitation; physical similarity simulation; triaxial compression; gas outburst elimination; crosscut uncovering.
  DOI: 10.1504/IJOGCT.2023.10058651
   
  
• Optimising chemical concentration and injection volume in the ASP process: a combined approach incorporating experiments and the optimal experimental design  
  by Pham Huu Tai, Nguyen Xuan Huy, Linh Hai Luong, Nguyen Viet Khoi Nguyen 
  Abstract: The efficiency of utilising an alkaline-surfactant-polymer (ASP) flooding technique for enhanced oil recovery is primarily reliant on the middle-phase microemulsion that forms between the ASP solution and oil. This microemulsion phase exhibits ultralow interfacial tensions, contributing to increased oil recovery. In this study, an optimal experimental design and response surface methodology were employed to predict the ideal concentration of chemicals in the ASP solution for achieving maximum microemulsion quality. Subsequently, the optimised ASP formulation was tested on 10 core flooding experiments to determine the most effective injection volume. The findings revealed that the optimal concentration of surfactants in the ASP solution was 0.57 wt%, while the effective injection volume reached 19.47% of the pore volume. [Received: July 14, 2022; Accepted: July 14, 2023]
  Keywords: alkaline-surfactant-polymer; ASP flooding; alpha olefin sulfonate; Box-Behnken design; solubilisation ratio; response surface methodology; RSM.
  DOI: 10.1504/IJOGCT.2023.10058770
   
  
• Beyond conventional approach: hybrid supervised learning and feature selection algorithms for prediction sonic logs - a study in a tight gas sand, North of Oman  
  by Suad Al-Handhali, Mohammed Al-Aamril, Narasimman Sundararajan 
  Abstract: The sonic log is an essential petrophysical log, and it is used in many petroleum applications. Since sonic logs are expensive to run in all boreholes, oil companies conduct them in a few wells. Thus, several workflows incorporate sonic log synthetisation using conventional empirical correlations. However, these traditional approaches are less reliable than modern-day machine learning techniques. This study combines machine learning and feature selection algorithms to predict synthetic sonic logs from basic petrophysical logs. The implemented machine learning algorithms are multi-linear regression (MLR), artificial neural network (ANN), support vector machine (SVM) and random forest (RF). This study was implemented with data from seven wells in North Oman’s tight gas sandstone. The models developed were built and evaluated. The results show that the hybrid random forest algorithm with a backward elimination feature selection approach was more robust and reliable for predicting sonic logs. [Received: 22 November 2022; Accepted: 12 April 2023]
  Keywords: petrophysics; sonic; machine learning; feature selection; multi-linear regression; artificial neural network; support vector machine; random forest; tight sand; backward elimination.
  DOI: 10.1504/IJOGCT.2023.10059018
   
  
• Assessing the impact of blends of olea europaea oil methyl esters and diesel bio-diesel on ci engine performance and emission characteristics: a comparative study  
  by Venkata Ramesh Mamilla, Subbarama Kousik Suraparaju 
  Abstract: The surging demand for renewable energy has propelled biofuels into the spotlight as a viable substitute for fossil fuels. This study investigates the feasibility and advantages of biofuels in fostering sustainability while addressing environmental concerns. Specifically, it assesses a compression ignition (CI) engine’s performance under varying load conditions using blends of olive oil methyl esters (OME) and diesel. Engine performance is evaluated under consistent speed and steady-state conditions, with a focus on brake thermal efficiency (BTE). Results indicate that at full loads, blends B0, B20, B40, and B60 exhibit BTE values of 29.02%, 27.90%, 31.30%, and 30.01% respectively, akin to diesel. Additionally, B20, B40, and B60 show slightly lower CO emissions (approximately 0.23%, 0.21%, and 0.24%) compared to diesel (0.25%), while NOx emissions are slightly elevated. Overall, among the blends, B20 showcases superior emissions and engine performance. [Received: April 27, 2023; Accepted: August 4, 2023]
  Keywords: biofuels; olive oil; engine combustion; diesel engine; engine emissions.
  DOI: 10.1504/IJOGCT.2023.10059198
   
  
• Investigations of coal permeability under the influence of stress, matrix-fracture adsorption induced strain and volumetric strain  
  by Haizeng Pan, Chaoyu Xu, Xiaochuan Wang 
  Abstract: The evolution and distribution of coal seam permeability have a significant role to play during CBM extraction. Many permeability models assume that coal is isotropic, however, the assumption has received a lot of skepticism. In this study, an improved fracture permeability model is established, considering the anisotropy of coal. The relationship among matrix adsorption strain, fracture adsorption strain, and volume strain of coal is defined. Fracture permeability is a feature of pressure and strain caused by fracture and matrix adsorption. At the same time, the permeability model is validated by experimental data, and the results are in good accordance with the experimental data. The simulation results show that the fracture permeability in the compression direction is smaller than in the tensile direction, and the peak fracture pressure will be delayed in the non-Darcy condition. Cracks are the main passage of CBM. Therefore, studying the permeability of fractures in different directions can better improve the production of coalbed methane. [Received: January 12, 2023; Accepted: May 8, 2023]
  Keywords: permeability; anisotropic; adsorption induced strain; numerical model; coalbed methane; CBM.
  DOI: 10.1504/IJOGCT.2023.10059216
   
  
• A new automatic differentiation approach for fully implicit compositional reservoir simulation  
  by Bruno Ramon Batista Fernandes, Francisco Marcondes, Kamy Sepehrnoori 
  Abstract: A new stand-alone object-oriented automatic differentiation (AD) tool for FORTRAN 95 codes is presented for facilitating the development of implicit solutions of PDEs. Five different AD approaches were implemented and tested: a forward mode (FM) with static allocation, an FM with dynamic allocation and memory stack, an expression-level reverse mode (RM) with memory stack, an expression-level RM with pointers, and a fully RM with pointers. The new tool is applied to an in-house chemical enhanced oil recovery simulator using three approaches: seed matrix, localised linearisation, and using AD only for computing gridblock properties. The FM AD with static allocation was the fastest AD approach but didn't have the flexibility for problems with variable gradient size. Among the AD coupling techniques, the localised linearisation presented a better performance for assembling the Jacobian when compared to the seed matrix scheme. The use of AD for computing properties only presented the smallest overhead. [Received: May 10, 2023; Accepted: June 1, 2023]
  Keywords: automatic differentiation; reservoir simulation; implicit methods; chemical flooding; operator overloading; expression-level reverse mode.
  DOI: 10.1504/IJOGCT.2023.10058003
   
  
• Numerical modelling of the process of thermal treatment of oil slime  
  by Gulnar Balakayeva, Gaukhar Kalmenova, Chris Phillips 
  Abstract: This article proposes modelling processing oil waste to minimise the harmful impact on the environment. The available research is limited to one-dimensional models. The novelty of the work lies in the new mathematical and numerical model of convective heat-mass transfer in oil slime. The mathematical two-dimensional model is constructed that describes heat and mass transfer during the evaporation of harmful substances from the oil slime. The numerical solution of this mathematical model is based on the alternating directions implicit (ADI) method. The calculations were carried out for comparison with experimental data of other authors at different temperatures of 150°C, 250°C, 450°C, and at speeds of 0.83 m/s, 1.6 m/s, and 2.7 m/s. The calculation results obtained correctly describe the processes of heat and mass transfer during the thermal treatment of oil slime. For interactive user analysis of oil-slime processing, a software application has been developed using Python software tools. [Received: July 4, 2022; Accepted: April 2, 2023]
  Keywords: oil slime; modelling; heat and mass; two-dimensional model; numerical solution; environment; software package; the alternating-direction implicit method; ADI.
  DOI: 10.1504/IJOGCT.2023.10059259
   
  
• Design and experimental investigation of a natural gas burner for pellet rotary kilns  
  by Shaobo Ma, Wenqiang Sun 
  Abstract: Traditional natural gas burners have the problem of a short flame in large-scale industrial furnaces or kilns. To solve this problem, this work designs a new natural gas burner for pellet rotary kilns in the context of replacing coal with natural gas in industrial applications. The structural parameters of the burner are designed, and an experimental study is conducted to verify its applicability to pellet rotary kilns. The flame stability and shape are experimentally investigated. With the increase in natural gas flow rate, the stability of the flame in the kiln gradually increases. The flame length and radius in the kiln increase with the increase in the natural gas flow rate, decrease with the increase in the excess air coefficient, decrease with the increase in the primary air flow rate, increase with the decrease in the kiln head pressure, and have little relation to the secondary air flow rate. [Received: May 23, 2023; Accepted: June 3, 2003]
  Keywords: rotary kiln; natural gas burner; flame length; flame radius; flame stability.
  DOI: 10.1504/IJOGCT.2023.10058037
   
  
• Rock-breaking characteristics and impact resistance mechanism of ridged PDC cutters  
  by Zhijie Chen, Yang Li, Qi Peng, Weiqiang Xu, Shiwei Niu, Haitao Ren, Yingxin Yang 
  Abstract: In recent years, the high impact resistance of ridged PDC cutters has made them widely used in hard heterogeneous formations. However, theoretical studies on the impact resistance of ridged PDC cutters are still lacking. In this paper, we conduct linear cutting tests and found that the cutting surface of ridged PDC cutter can prevent the accumulation and compaction of rock debris, which significantly reduces the cutting force and mechanical specific energy (MSE), thereby increasing cutting efficiency. Then, when we analysed the vibration amplitude, frequency and rate of change of the load in the simulation, we found that the rate of change of the cutting load approximate Weibull distribution. Moreover, the load vibration amplitude and load rate of change of the ridged PDC cutter are smaller than those of the planar PDC cutter, which weakens the impact effect during the cutting process. The research results of this article can help us evaluate the impact degree of PDC cutters with different shapes when cutting rocks under different conditions. To provide assistance in optimising the shape and working parameters of PDC cutters in the future, in order to reduce impact and extend the cutting life of PDC cutters. [Received: September 8, 2022; Accepted: June 4, 2023]
  Keywords: ridged PDC; impact resistance; load rate of change; Weibull distribution.
  DOI: 10.1504/IJOGCT.2023.10058395
   
  
• Emission analysis of esterified mahua oil fuelled with DTBP blends in conventional diesel engine  
  by Nalla Bhanu Teja, Karthikeyan Natarajan, Ramesh Adireddy, Rajendra Prasad Arani, Sudhakar Meganathan, Tien Anh Tran 
  Abstract: The experiments are conducted with mahua oil methyl ester 1% DTBP enhancer and compared with standard diesel. The methyl ester was prepared from mahua oil by transesterification process. The produced fuel was blended with 1% DTBP along mineral diesel in various proportions for conducting experiments in conventional diesel engine. Generally, emissions will be reduced when additives are added in the methyl ester. The current work is carried with mahua oil methyl ester along with an enhancer DTBP, which is the promising additive in controlling NOX as it reduces the ignition delay during combustion. The other emissions such as CO, CO₂, HC and opacity have reduced more after adding DTBP. Thus, it helps the global economists to setup perfect solution to the pollution problem and serves as a brilliant substitute for the conventional fuels. [Received: May 12, 2022; Accepted: November 30, 2022]
  Keywords: DTBP; mahua methyl ester; enhancer; conventional fuels and emissions.
  DOI: 10.1504/IJOGCT.2023.10058264