Hasil untuk "Petroleum refining. Petroleum products"

C. Quispe, Christian J. R. Coronado, J. Carvalho

Rufaida T. Ibrahim, Watheq J. Al-Mudhafar, Dahlia A. Alobaidi et al.

Abstract Anthropogenic CO2 emissions are a key factor in global climate change, necessitating technologies that improve energy security and enable permanent CO2 sequestration. CO2-enhanced oil recovery (CO2-EOR), combined with carbon capture, utilization, and storage (CCUS), offers a strategy to boost hydrocarbon production while reducing atmospheric CO2. However, challenges such as reservoir heterogeneity, early gas breakthrough, and inefficient sweep dynamics hinder its widespread deployment, affecting both economic viability and storage permanence. This comprehensive review, therefore, examines the historical evolution, fundamental mechanisms, and future potential of CO2-EOR. A critical analysis of advanced injection techniques—continuous gas injection (CGI), water-alternating-gas (WAG), and gas-assisted gravity drainage (GAGD)—addresses persistent challenges including gas breakthrough, poor sweep efficiency, and reservoir heterogeneity. The physicochemical mechanisms of CO2-EOR, such as miscibility, capillary effects, and displacement efficiencies, are detailed, with a comparative assessment of horizontal versus vertical flooding approaches. The GAGD process is highlighted as a gravity-dominated alternative, with analysis focused on its underlying mechanisms, operational parameters, and dimensionless governing forces. Furthermore, the integration of CO2-EOR with carbon capture and storage (CCS) is explored as a dual strategy for emission reduction and reservoir revitalization. The review also evaluates economic and environmental criteria for CO2 selection, reservoir complexities, and containment risks. By synthesizing current practices, challenges, and advancements, this work positions CO2-EOR as an essential approach for aligning energy production with decarbonization targets, with its novelty lying in a focused analysis of gravity-stable processes and their integration within the carbon utilization and storage framework.

Zeyu Zhang, Guohao Li, Zhenchang Xing et al.

The ability to use tools is fundamental for large language model (LLM) agents. Given a task, existing systems use LLMs to plan and generate tool calls, which are executed by real-world tools to complete the task. However, tool calls are prone to errors because they are derived merely from LLM intrinsic capabilities. What is more, while it is useful to let LLMs iteratively refine the tool-call sequence using execution results from real tools, this process can be expensive and lead to unsafe results. To improve LLM tool calls and address issues caused by using real tools for refinement, we introduce Gecko, a comprehensive environment that simulates tool responses using a combination of rules and LLMs. Specifically, Gecko checks the validity of tool calls including input arguments and tool names, synthesizes reasonable responses that adhere to the output schema, and assesses whether all task objectives have been achieved. These three types of feedback provided by Gecko allow LLMs to refine their tool calls, forming a simple yet effective test-time scaling method named GATS. On BFCLv3 and $τ^2$-bench, GATS consistently improves the tool calling performance of various LLMs including GPT-4o, GPT-5, and Gemini-3.0-pro. We further discuss working mechanisms of our method and share future possibilities.

Yang GAO, Huimin LIU

Based on a large amount of basic research and experimental analysis data from Shengli Oilfield, Bohai Bay Basin, guided by the theory of whole petroleum system, the distribution of sedimentary systems, the distribution and hydrocarbon generation and expulsion process of source rocks, the variation of reservoir properties, and the control of fracture systems on hydrocarbon accumulation in the Paleogene of the Jiyang Depression, Boahai Bay Basin, were systematically analyzed, and the geological characteristics of the whole petroleum system in the rift basin were identified. Taking the Dongying Sag as an example, combined with the distribution of discovered conventional, tight, and shale oil/gas, a hydrocarbon accumulation model of the fault-controlled whole petroleum system in rift basin was proposed, and the distribution patterns of conventional and unconventional oil and gas reservoirs in large geological bodies horizontally and vertically were clarified. The research results show that paleoclimate and tectonic cycles control the orderly distribution of the Paleogene sedimentary system in the Jiyang Depression, the multi-stage source rocks provide sufficient material basis for in-situ shale oil/gas accumulation and other hydrocarbon migration and accumulation, the changes in reservoir properties control the dynamic threshold of hydrocarbon accumulation, and the combination of faults and fractures at different stages controls hydrocarbon migration and accumulation, and in-situ retention and accumulation of shale oil/gas, making the whole petroleum system in the rift basin associated, segmented and abrupt. The above elements are configured to form a composite whole petroleum system controlled by faults in the Paleogene of the Jiyang Depression. Moreover, under the control of hydrocarbon accumulaiton dynamics, a whole petroleum system can be divided into conventional subsystem and unconventional subsystem, with shale oil, tight oil and conventional oil in an orderly distribution in horizontal and vertical directions. This systematic understanding is referential for ananlyzing the whole petroleum system in continental rift basins in eastern China.

J. J. Ajali, L. Emembolu

This study investigated oil extraction from rice bran a by-product of rice gotten from different sources (Afikpo, Abakaliki, and Emene). The oil was extracted from different particle sizes (150 µm, 300 µm, and 420 µm) of the rice bran using three different solvents namely chloroform, petroleum ether, and n-hexane at constant time of 120 minutes via soxhlet extractor. The physiochemical properties of the extracted oil were boiling point, the saponification values and refractive index were 77 oC, 185.130, and 1.334, respectively. Also the acid value, surface tension, iodine value, and relative density were found to 15.040 g, 6.966×102 N/M, 99.480, and 0.779, respectively. The obtained result based on source revealed that the maximum oil yield of 35.05 g was achieved from Abakaliki rice bran using chloroform solvent and particle size of 420 mm, whereas Emene and Afikpo gave 32.62 g and 14.18 g of oil, respectively from same solvent and particle size. Again, the highest volume of oil obtained in terms of solvent used were chloroform, petroleum ether, and n-hexane, in descending order. The physicochemical properties investigated, showed that the extracted rice bran oil (RBO) from the above three sources in Nigeria confirms RBO to be of good quality and can be utilized in many food industries after refining in form of additives/or industrial purposes as well as in generation of energy.

Deke Zhao

The article is concerned with the Foulkes characters of wreath products, which are block characters of wreath products, i.e., the positive-definite class functions depending only on the length of its elements. Inspired by the works of Gnedin--Gorin--Kerov and Miller, we introduce two specializations of the Schur--Weyl--Sergeev duality for wreath products and obtain two families of block characters, which provide a decomposition and an alternative construction of the Foulkes characters of wreath products. In particular, we give alternative proofs on some remarkable properties of the Foulkes characters. Along the way, we show that the Foulkes characters are the extreme rays of the cone of the block characters of wreath products and construct the representations with traces being the Foulkes characters via the coinvariant algebra of wreath products.

Sahil Goyal, Abhinav Mahajan, Swasti Mishra et al.

Graphic designs are an effective medium for visual communication. They range from greeting cards to corporate flyers and beyond. Off-late, machine learning techniques are able to generate such designs, which accelerates the rate of content production. An automated way of evaluating their quality becomes critical. Towards this end, we introduce Design-o-meter, a data-driven methodology to quantify the goodness of graphic designs. Further, our approach can suggest modifications to these designs to improve its visual appeal. To the best of our knowledge, Design-o-meter is the first approach that scores and refines designs in a unified framework despite the inherent subjectivity and ambiguity of the setting. Our exhaustive quantitative and qualitative analysis of our approach against baselines adapted for the task (including recent Multimodal LLM-based approaches) brings out the efficacy of our methodology. We hope our work will usher more interest in this important and pragmatic problem setting.

P. Chen, Uisung Lee, Xinyu Liu et al.

Catalytic hydrothermolysis (CH) is a sustainable aviation fuel (SAF) pathway that has been recently approved for use in aircraft fuel production. In alignment with broader sustainable aviation goals, SAF production through CH requires a quantitative assessment of carbon intensity (CI) impacts. In this study, a current‐day life‐cycle analysis (LCA) was performed on SAF produced via CH to determine the CI. Various oily feedstocks were considered, including vegetable oils (soybean, carinata, camelina and canola) and low‐burden oils and greases (corn oil, yellow grease and brown grease). Life‐cycle inventory data were collected on all processes within the CH LCA boundary: feedstock cultivation and/or collection, preprocessing, hydrothermal cleanup and CH, biocrude refining, fuel transportation and end use through combustion. Baseline results show that the CH‐produced SAF can be generated with CI reductions ranging from 48 to 82% compared with conventional jet fuel. Modest improvements to CI can be achieved through incremental changes to the brown grease CH process, such as relaxing the dewatering specification and implementing renewable natural gas and electricity, which could decrease the CI from 22.9 to 7.9 g CO2e/MJ. Total CH fuel production potential was also assessed on the basis of current or near‐future feedstock availability and CI. The total biofuel production potential of CH (SAF and renewable fuel co‐products) in the US sums to approximately 3487 million gallons per year, with 97% of these volumes having a CI below 50% of that for petroleum jet fuel. The study shows that from an LCA perspective, CH offers a viable SAF pathway that is comparable with existing SAF pathways like hydroprocessed esters and fatty acids.

Junlong LIU, Zhongqun LIU, Zhenfeng LIU et al.

In the second member of the Upper Triassic Xujiahe Formation (T3x2) in the Xinchang area, western Sichuan Basin, only a low percent of reserves has been recovered, and the geological model of gas reservoir sweet spot remains unclear. Based on a large number of core, field outcrop, test and logging-seismic data, the T3x2 gas reservoir in the Xinchang area is examined. The concept of fault-fold-fracture body (FFFB) is proposed, and its types are recognized. The main factors controlling fracture development are identified, and the geological models of FFFB are established. FFFB refers to faults, folds and associated fractures reservoirs. According to the characteristics and genesis, FFFBs can be divided into three types: fault-fracture body, fold-fracture body, and fault-fold body. In the hanging wall of the fault, the closer to the fault, the more developed the effective fractures; the greater the fold amplitude and the closer to the fold hinge plane, the more developed the effective fractures. Two types of geological models of FFFB are established: fault-fold fracture, and matrix storage and permeability. The former can be divided into two subtypes: network fracture, and single structural fracture, and the later can be divided into three subtypes: bedding fracture, low permeability pore, and extremely low permeability pore. The process for evaluating favorable FFFB zones was formed to define favorable development targets and support the well deployment for purpose of high production. The study results provide a reference for the exploration and development of deep tight sandstone oil and gas reservoirs in China.

LIU Xin, LI Ning, LI Zhen et al.

The horizontal well and volume fracturing technology can effectively increase the production of a single well in ultra-low permeability tight reservoirs. However, the production of a single well decreases rapidly by relying solely on natural energy production. Therefore, it is urgent to explore new ways to supplement energy to improve the recovery efficiency of tight reservoirs. In this paper, the ultra-low permeability tight oil reservoir in block X is taken as the research objective, and combined with the actual situation of the field, the mechanism model of one injection and two production was established. The effects of injection timing, injection gas volume, gas injection speed and daily oil production on the oil increase effect were studied. The results show that the injection timing is negatively correlated with the recovery factor, and the earlier the injection timing, the better the recovery factor. Too low injection gas and gas injection speed can not effectively supplement formation energy, but too high injection gas and gas injection speed will lead to high injection pressure, difficult for injection and other problems. Too low daily oil production is not conducive to the economic development of the reservoir, and too high daily oil production will reduce the oil displacement efficiency. An optimal development scheme is obtained by optimizing hydrocarbon gas flooding parameters, which provides theoretical guidance and reference for the efficient development of other similar ultra-low permeability tight reservoirs.

R. L. Upton, Romy A. Dop, Emma Sadler et al.

Elemental sulfur (S8), a by-product of the petroleum refining industries, possesses many favourable properties including photocatalytic activity and antibacterial activity, in addition to being intrinsically hydrophobic. Despite this, there is a relative lack of research employing elemental sulfur and/or sulfur copolymers within superhydrophobic materials design. In this work, we present the use of sulfur copolymers to produce superhydrophobic materials with advanced functionalities. Using inverse vulcanization and the use of a natural organic crosslinker, perillyl alcohol (PER), stable S8-PER copolymers were synthesised and later combined with silica (SiO2) nanoparticles, to achieve highly water repellent composites that displayed both antimicrobial and photocatalytic properties, in the absence of carcinogenic and/or expensive materials. Here, we investigated the antibacterial performance of coatings against the Staphylococcus aureus bacterial strain, where coatings displayed great promise for use in antifouling applications, as they were found to limit surface adhesion by more than 99%, when compared to uncoated glass samples. Furthermore, UV dye degradation tests were performed, utilizing the commercially available dye resazurin, and it was shown that coatings had the potential to simultaneously exhibit surface hydrophobicity and photoactivity, demonstrating a great advancement in the field of superhydrophobic materials.

Ali Hussein Humod Al Jlibawi, M. Othman, Aris Ishak et al.

In this research, prediction of crude oil cuts from the first stage of refining process field is laid out using rough set theory (RST) based adaptive neuro-fuzzy inference system (ANFIS) soft sensor model to enhance the performance of oil refinery process. The RST was used to reduce the fuzzy rule sets of ANFIS model, and its features in the decision table. Also, discretisation methods were used to optimise the continuous data’s discretisation. This helps to predict the two critical variables of light naphtha product: Reid Vapor Pressure (RVP) and American Petroleum Institute gravity (API gravity), which detect the cut’s quality. Hence, a real-time process of Al Doura oil refinery is examined and the process data of refining crude oil from these two sources improve the knowledge provided by the data. The response variables represent the feedback measured value of cascade controller in the top of the splitter in crude distillation unit (CDU) in the rectifying section, which controls the reflux liquid’s flow towards the splitter’s head. The proposed adaptive soft sensor model succeeded to fit the results from laboratory tests, and a steady-state control system was achieved through an embedded virtual sensor. The predictive control system has been employed using cascade ANFIS controller in parallel with the soft sensor model to keep the purity of the distillate product in the stated range of the quality control of oil refinery. The results obtained from the proposed ANFIS based cascade control have no over/undershoots, and the rise time and settling time are improved by 26.65% and 84.63%, respectively than the conventional proportional-integral-derivative (PID) based cascade control. Furthermore, the results of prediction and control model are compared with those of other machine learning techniques.

M. Fouad Snosy, Mahmoud Abu El Ela, Ahmed El-Banbi et al.

Low salinity water flooding (LSWF) was initially considered using water with a low concentration of dissolved salts and was later extended to include modifying the ionic content of injected brines. This work investigates the effects of changing water salinity and composition along with the concentration of sulfate and iodide ions on oil recovery in carbonate reservoirs during the tertiary recovery stage. An experimental study was carried out using crude oil of 29°API, 8 core samples extracted from the Eocene carbonate reservoir (Egypt), and 6 different water salinities.The results showed additional oil recovery up to 5% of the original oil in place (OOIP) in the tertiary recovery stage with changing water salinity and water composition. Injection of high salinity (HS) and low salinity (LS) brines with high sulfate concentrations increased the incremental oil recovery by a value ranging from 1.7 to 3.8% of the OOIP. On the contrary, injection of HS and LS brines with low sulfate concentrations showed insignificant incremental oil recovery (less than 1% of the OOIP). Furthermore, injection of water with potassium iodide (KI) after injection of water with high sulfate brines showed additional oil recovery of about 1.7% of the OOIP. On the other hand, injection of water with KI after injection of water with low sulfate concentration showed insignificant incremental oil recovery (less than 0.4% of the OOIP).The concentration of sulfate in the injected water appeared to be key parameter to achieve effective waterflooding (WF) projects in carbonate reservoirs. Moreover, the results revealed that the multi-component ion exchange (MIE) mechanism seems to be the primary recovery mechanism for LSWF in carbonate reservoirs. The results and conclusions of this study can be used to develop guidelines for designing waterflooding projects in carbonate reservoirs with optimum salinity.

Sun Lechen, Wan Jingjing, Du Tianhao et al.

In order to inspect the oil pipelines quickly and accurately,an internal inspection robot was designed,which can run independently,carry inspection equipment,ensure a wide range of diameter change and adapt to smaller diameter pipelines.The robot can travel in the pipeline by its own power,and at the same time,it can use ultrasonic flaw detection to detect various defects on the pipeline wall such as corrosion,cracks,dislocation and obstacles,and record the locations of the defects.With an active driving module,the pipeline robot can run independently in the oil pipeline.Its rated moving speed is 5 cm/s,the maximum test distance is 1 km,and the minimum cornering radius is 813 mm.The driving module uses a synchronous belt,which greatly improves its obstacle-surmounting ability and the stability of movement.The variable diameter of the lifting variable diameter mechanism ranges from 114 mm to 325 mm and the ideal detection range of the pipeline robot probe occupies 84% of the inner wall area of the pipeline.This design provide a reference for the defect inspection of oil pipelines.

Yu Hao, Zhao Zhaoyang, Lian Zhanghua et al.

The wellhead uplift will lead to wellbore integrity damage of oil and gas wells and affect the safety of subsequent production of oil wells. In order to study the wellhead stress distribution and uplift height variation of the tieback casing string in cementing-production operation, with the help of the finite element method, based on the field working conditions of a well in Shunbei Block, the ABAQUS software was used to build a thermal-solid coupling analysis finite element model of multilayer casing-cement sheath-formation system under different working conditions, so as to analyze the stress and displacement variation of tieback casing from cementing stage to production. The analysis results show that as the cement top increases, the wellhead uplift height increases monotonously, indicating that as the severity of cement sheath loss increases, the longer the number of free sections of casing, the greater the height of elongation and uplift under temperature difference effect is; and as the cement top increases, the Mises stress of the tieback casing at the time of wellhead fixation increases first and then decreases, and does not show a monotonous increasing or decreasing trend. The study results provide some reference for the analysis of wellhead uplift phenomenon caused by field tieback casing string.

Amin Shabani, Amir Abdi, Lili Meng et al.

The performance of time series forecasting has recently been greatly improved by the introduction of transformers. In this paper, we propose a general multi-scale framework that can be applied to the state-of-the-art transformer-based time series forecasting models (FEDformer, Autoformer, etc.). By iteratively refining a forecasted time series at multiple scales with shared weights, introducing architecture adaptations, and a specially-designed normalization scheme, we are able to achieve significant performance improvements, from 5.5% to 38.5% across datasets and transformer architectures, with minimal additional computational overhead. Via detailed ablation studies, we demonstrate the effectiveness of each of our contributions across the architecture and methodology. Furthermore, our experiments on various public datasets demonstrate that the proposed improvements outperform their corresponding baseline counterparts. Our code is publicly available in https://github.com/BorealisAI/scaleformer.

Shigemichi Matsuzaki, Hiroaki Masuzawa, Jun Miura

This paper describes a method of online refinement of a scene recognition model for robot navigation considering traversable plants, flexible plant parts which a robot can push aside while moving. In scene recognition systems that consider traversable plants growing out to the paths, misclassification may lead the robot to getting stuck due to the traversable plants recognized as obstacles. Yet, misclassification is inevitable in any estimation methods. In this work, we propose a framework that allows for refining a semantic segmentation model on the fly during the robot's operation. We introduce a few-shot segmentation based on weight imprinting for online model refinement without fine-tuning. Training data are collected via observation of a human's interaction with the plant parts. We propose novel robust weight imprinting to mitigate the effect of noise included in the masks generated by the interaction. The proposed method was evaluated through experiments using real-world data and shown to outperform an ordinary weight imprinting and provide competitive results to fine-tuning with model distillation while requiring less computational cost.

K. Kang, N. Nguyen, Duy Van Pham et al.

A. Pauline, K. Joseph

Bowen Zhang, L. Dodd, Peiyao Yan et al.

Abstract The refining of petroleum feedstocks has produced a surplus of the by-product elemental sulfur that is currently underused and is therefore, extremely low cost. The combination of sulfur with organic crosslinking units by inverse vulcanization polymerization, provides a route to low cost materials with a wide array of potential applications. To fully exploit the availability of elemental sulfur and to allow the product polymers to align well with the principles of green chemistry, a renewable crosslinker is desirable. Reported here is a polymer formed from inverse vulcanization, produced from industrial waste sulfur, and bio-derived garlic oil blend. This polymer has tuneable properties when blended with another industrial waste product, dicyclopentadiene. These polymers were found to have a high affinity to capture mercury, particularly for low mercury concentrations where other sorbents are often not effective. It is these low concentrations that are most industrially relevant and important for environmental and health concerns as even low concentrations of toxic mercury can have cumulative and severe consequences. Crucially, these ternary polymer systems are mechanically robust due to their increased glass transition temperatures and hardness values, making them viable for practical applications.