Hasil untuk "Petroleum refining. Petroleum products"

QIU Kang, WANG Lihua, CUI Qiang, WANG Ying, WANG Xiaoshan, XIONG Zhenyu

The Qiongdongnan Basin is located in the northwestern part of the continental shelf in the northern part of the South China Sea, which is a Cenozoic highly-overpressured, transformed, and extended basin with abundant oil and gas resources. The Qiongdongnan Basin is also a typical offshore HTHP basin in China, and is one of the world’s top 3 offshore HTHP areas, with the highest reservoir temperature of over 240 ℃ and the highest formation pressure coefficient of 2.3, which makes it one of the most difficult areas for domestic and international drilling operations. The complex genesis mechanism of abnormal high pressure in the Qiongdongnan Basin of the South China Sea results in great difficulty and low accuracy of pre-drilling pressure prediction, which seriously compromises drilling safety. Block 64/07 of Lingshui structure in Qiongdongnan Basin was taken as the research object. Through analysis of tectonic evolution and loading/unloading mechanisms, the coupling genesis mechanisms of abnormal high pressure in this block were revealed, a multi-mechanism coupling pressure prediction method was specifically established, and formation pressure profiles of drilled wells and a 3D regional formation pressure model were constructed, systematically analyzing the vertical and horizontal pressure systems of this block. The Qiongdongnan Basin has experienced many rounds of tectonic evolution since the Paleocene, forming a huge thickness of Paleocene-Neocene and Quaternary sediments. From the perspective of the depositional history of the Qiongdongnan Basin, the sedimentation rate of the whole basin is relatively high, with two distinct peaks. The first peak occurred in the fracture to fracture-argument period, with a subsidence rate exceeding 600 m/Ma. The second appeared during the post-fracture rapid subsidence period, with the Yinggehai Formation reaching 600~1 700 m/Ma. Both rates exceeded the 150 m/Ma threshold for overpressure, and these periods were prone to the formation of anomalous high pressures with undercompaction mechanisms. These processes were the basis of the overpressure prevalent across the entire basin, and were manifested as loading-type anomalous high pressures. Meanwhile, the FS fracture zone in this region had the ability to transmit oil and gas, forming a two-way hydrocarbon supply pattern between the main depression and the secondary depression in western Lingshui. The hydrocarbons had two large-scale hydrocarbon discharge periods (15 Ma and 5 Ma), and the Meishan~Sanya Formation underwent prolonged effective charging, creating conditions for high pressure caused by fluid charging, which was the most probable auxiliary cause of anomalous high-pressure formation in this region. Using the logging data of the drilled wells, the rock density-sound wave velocity crossplot of the stratified sections was established, and the Meishan Formation showed a composite mechanism of loading and unloading. Combined with the tectonic evolution history, it could be inferred that the anomalously high pressure of Yinggehai and Huangliu Formations was attributed to the undercompaction mechanisms, and the anomalously high pressure of Meishan Formation resulted from the coupling mechanism of undercompaction and fluid filling. To address the high-pressure coupling genesis mechanism of this block, this study developed a multi-mechanism coupling pressure prediction method. The upper Yinggehai Formation and Huangliu Formation under-compacted strata were evaluated using the conventional Eaton method, and the lower Meishan Formation and Sanya Formation stratigraphic over-pressure zones were analyzed using the multi-parameter effective stress method, thereby overcoming the limitations of single-method prediction and improving prediction accuracy. Based on this method, a high-precision three-dimensional stratigraphic pressure body was constructed in Lingshui tectonic block 64/07, revealing the vertical and horizontal distribution patterns of stratigraphic pressure in this block. The results showed that the high pressure in formations above Huangliu Formation in this area was caused by undercompaction mechanism, while below Meishan Formation it was caused by the coupling mechanism of undercompaction and fluid charging. Vertically, pressure began to increase in the middle and lower part of Yinggehai Formation, Huangliu Formation served as the pressure transition zone, and Meishan and Sanya Formations entered the overpressure zone, with the highest pressure coefficient reaching 2.10. Horizontally, it generally presented the characteristics of “low in the west and high in the east, low in the north and high in the south”. These research findings were applied to well L5-1. The core of this method lay in addressing the coupling genesis of formation pressure in the Meishan Formation by establishing a multi-parameter effective stress method. Parameters such as shale content, porosity, and effective stress of the lower high-pressure layer were introduced, avoiding the difficult problem of determining original sedimentary loading and subsequent unloading, thereby achieving accurate prediction of reservoir high pressure. During the drilling process of well L5-1, a combination of pre-drilling pressure prediction, logging monitoring, logging constraints on seismic layer velocity and MDT pressure correction were used to follow up and monitor the trend of pressure change throughout the entire process in real time. The entire pressure monitoring process could be divided into four stages: (1) determining the starting pressure layer at the pre-drilling design stage as the bottom of Ledong Formation and the top area of Yinggehai Formation; (2) adjusting the starting pressure depth from 2 100 m to 1 850 m based on the three-opening single-root gas pressure and the pressure monitoring profile with drilling; (3) using the four-opening electroacoustic constraints to recalibrate the extracted layer velocity, combined with the MDT pressure measurements, to correct the parameters of the prediction model; (4) conducting five-opening monitoring and the DST test after completion of drilling to complete the real drilling pressure evaluation. Using this method, the average accuracy of pre-drilling formation pressure prediction was 87.1%. During actual drilling, based on logging and test data, prediction results were timely corrected, and the prediction accuracy of lower formation pressure was improved to 98.8%, meeting the requirements for drilling design and field construction.

Xue Dedong, Kou Lei, Zheng Chunfeng et al.

Gas injection is a critical technique to replenish formation pressure for enhancing oil recovery in low-permeability oilfields. At present， the single-string separate-layer gas injection with throwing and fishing gas nozzles is adopted in the Bohai Oilfield， but it cannot read downhole data in a real-time manner while regulation and thus fails to accurately adjust the injection volume. This paper presents the concentric fine separate-layer gas injection process for offshore oilfields and develops associated tools and techniques. Among these tools， the gas injection measurement and adjustment working cylinder with maximum temperature and pressure resistance up to 150 ℃ and 60 MPa， respectively， can realize a stepless regulation of gas injection rate， and the gas flow tester relying on flow-concentrating test process can achieve test of individual intervals and also two-way communication with downhole equipment. Field applications have demonstrated successful measurement and adjustment of the concentric fine separate-layer gas injection process. The proposed process was verified to be applicable to wellbores with diameter of 98.55 mm and inclination not greater than 60°， and could effectively address the issues of gas sealing， gas corrosion， gas erosion， and gas injection safety. Moreover， it yielded a qualified injection rate reaching 95% and reduced the overall injection adjustment duration from 48 h to 12 h. This study provides a new technical option for efficient gas flooding in offshore low-permeability oilfields.

D. Stratiev

It has been proven that the performance of fluid catalytic cracking (FCC), as the most important oil refining process for converting low-value heavy oils into high-value transportation fuels, light olefins, and feedstocks for petrochemicals, depends strongly on the quality of the feedstock. For this reason, characterization of feedstocks and their relationships to FCC performance are issues deserving special attention. This study systematically reviews various publications dealing with the influence of feedstock characteristics on FCC performance, with the aim of identifying the best characteristic descriptors allowing prediction of FCC feedstock cracking capability. These characteristics were obtained by mass spectrometry, SARA analysis, elemental analysis, and various empirical methods. This study also reviews published research dedicated to the catalytic cracking of biomass and waste oils, as well as blends of petroleum-derived feedstocks with sustainable oils, with the aim of searching for quantitative relationships allowing prediction of FCC performance during co-processing. Correlation analysis of the various FCC feed characteristics was carried out, and regression techniques were used to develop correlations predicting the conversion at maximum gasoline yield and that obtained under constant operating conditions. Artificial neural network (ANN) analysis and nonlinear regression techniques were applied to predict FCC conversion from feed characteristics at maximum gasoline yield, with the aim of distinguishing which technique provided the more accurate model. It was found that the correlation developed in this work based on the empirically determined aromatic carbon content according to the n-d-M method and the hydrogen content calculated via the Dhulesia correlation demonstrated highly accurate calculation of conversion at maximum gasoline yield (standard error of 1.3%) compared with that based on the gasoline precursor content determined by mass spectrometry (standard error of 1.5%). Using other data from 88 FCC feedstocks characterized by hydrogen content, saturates, aromatics, and polars contents to develop the ANN model and the nonlinear regression model, it was found that the ANN model demonstrated more accurate prediction of conversion at maximum gasoline yield, with a standard error of 1.4% versus 2.3% for the nonlinear regression model. During the co-processing of petroleum-derived feedstocks with sustainable oils, it was observed that FCC conversion and yields may obey the linear mixing rule or synergism, leading to higher yields of desirable products than those calculated according to the linear mixing rule. The exact reason for this observation has not yet been thoroughly investigated.

Limin Wang, Zi Long, Tao Gu et al.

Emerging pollutants (EPs) associated with the petroleum industry present considerable challenges to environmental management and sustainable development. To support sustainable development and improve the control of EPs in the petroleum industry, this review systematically examines the functional uses of EPs as chemical additives across the entire petroleum supply chain—from extraction and transportation to refining and product blending. It also summarizes the environmental emissions, health impacts, mitigation strategies, and current regulatory frameworks of EPs. In addition, some challenges have been found, namely unclear data on EPs in chemical additives, insufficient attention to high-risk areas, undefined health risks of mixing EPs, lack of green assessment of alternative technologies, and regional policy disparities, which collectively hinder the effective prevention and management ofEPs. In response, we propose future perspectives including enhanced screening and substitution of high-EP-risk additives, development of source-specific fingerprinting techniques, expanded monitoring of mixed contaminants and understudied regions, accelerated deployment of green technologies, and strengthened global cooperation under sustainability-oriented governance frameworks. This study underscores the necessity of integrated, science-based approaches to align petroleum industry practices with global sustainability goals. This review underscores the critical need for a proactive and integrated approach toward the sustainable development of the petroleum industry through the control of and reduction in EPs.

Xinru Meng, Han Sun, Jiamei Liu et al.

Source-free domain adaptation (SFDA), which involves adapting models without access to source data, is both demanding and challenging. Existing SFDA techniques typically rely on pseudo-labels generated from confidence levels, leading to negative transfer due to significant noise. To tackle this problem, Energy-Based Pseudo-Label Refining (EBPR) is proposed for SFDA. Pseudo-labels are created for all sample clusters according to their energy scores. Global and class energy thresholds are computed to selectively filter pseudo-labels. Furthermore, a contrastive learning strategy is introduced to filter difficult samples, aligning them with their augmented versions to learn more discriminative features. Our method is validated on the Office-31, Office-Home, and VisDA-C datasets, consistently finding that our model outperformed state-of-the-art methods.

Vali Mehdipour, Ahmad Reza Rabbani, Ali Kadkhodaie et al.

Abstract The primary purpose of this study is to identify the high reservoir quality area for drilling and perforation of new wells using interrelated geological, petrophysical, and seismic data. Various datasets such as, core analysis data (two wells), petrophysical logs (twenty wells) and 3D seismic cube were used to consider different scenarios for optimum well placement based on the availability and accuracy of the data. Considering four criteria (structure, reservoir property, fracture network, and heterogeneity), various data were combined to assess reservoir potential. A static reservoir model was constructed to reduce the uncertainty of the well location determination. A range of scenarios were implemented based on this static reservoir model or by relying only on the available seismic data. Electrofacies analysis was conducted to establish representative facies with which to guide the forecasting of locations suitable for drilling the new wells. Six facies were determined based on multi-resolution graph-based clustering (MRGC) method. In parallel, 3D seismic data was applied to determine seismic facies and seismic attributes to identify high-quality reservoir areas for well placement. As high fracture intensity is an essential feature required for high oil/gas production rates, a continuous fracture model (CFM) was constructed, and average intensity fracture maps were developed to determine the best production locations and to avoid low-productivity (or potential loss-of-circulation zones) from a drilling perspective. Some structural issues, such as distances from transition zones and/or faults, were also considered for well-placement purposes. Coefficient of variation (as a heterogeneity criteria) was also taken into account for well-placement decision-making. The results indicate that applying the developed integrated approaches reduces well-placement uncertainty and delineates high-quality reservoir zones (or sweet spots) with more confidence.

ZHONG Hongli, WANG Guoxi, WU Jiuhu et al.

To explore the influence of differential diagenesis on the oil bearing properties of tight sandstone reservoirs， Chang 8 reservoirs with ultra-low porosity and ultra-low permeability in the Qingcheng area were used as an example. Based on the statistical cast thin section data of 337 samples and the scanning electron microscope （SEM） and high-pressure mercury injection data of 10 samples， the porosity evolution characteristics of different types of reservoirs were calculated， and the influence of differential diagenesis on the oil bearing properties of the reservoirs was analyzed. The research results show that the Chang 8 tight sandstone reservoirs in the Qingcheng area are mainly composed of lithic feldspar sandstone and feldspathic litharenite， with dissolution pores and residual intergranular pores developed. According to the characteristics of brittle mineral content， soft particle content， porosity， and calcareous cement content， the Chang 8 reservoirs can be divided into three types： high-porosity sandstone （Type Ⅰ）， high-porosity calcareous sandstone （Type Ⅱ）， and rich soft particle sandstone （Type Ⅲ）. Type Ⅰ reservoirs are mostly underwater distributary channel sand bodies and have the strongest compaction effect in the early diagenesis stage， with an average compaction porosity reduction rate of 60.0%， but they have a strong dissolution effect in the later stage， with an average dissolution porosity increase rate of 11.8%， weak cementation effect， and an average cementation porosity reduction rate of 27%. The average remaining porosity value is 9.5%. Type Ⅱ reservoirs are mostly underwater distributary channel sand bodies， and their estuarine bar sand body is slightly developed compared with Type Ⅰ reservoirs. The early calcium cementation of Type Ⅱ reservoirs is strong， and the compaction is relatively weak. The average compaction porosity reduction rate is 56.8%， and the average cementation porosity reduction rate is 34.1%； the average dissolution porosity increase rate is 11.5%， and the average remaining porosity is 7.9%. Type III reservoirs are more likely to develop in sand bodies along the side of underwater distributary channels. The early compaction of Type II reservoirs is not strong， with an average compaction porosity reduction rate of 49.3%， but the later dissolution is weak， with an average dissolution porosity increase rate of 10.5%. The late cementation is strong， with an average cementation porosity reduction rate of 43.2%. The final porosity is the lowest， with an average value of 6.9%. The pore throat radius of Type Ⅰ and Type Ⅱ reservoirs is concentrated in 0.1-1 μm， and the pore throat connectivity is good. The pore throat heterogeneity is weak， and the oil bearing property is good. The distribution of pore throat in Type III reservoirs is not concentrated， and the connectivity is poor； the pore throat heterogeneity is strong， and the oil bearing property is poor. In the Late Early Cretaceous， oil and gas migrated and accumulated on a large scale， and the three types of reservoirs were not densified. With the further densification of reservoirs in the middle diagenesis A stage， the differences in physical properties and pore throat structure of the three types of reservoirs are enhanced， affecting the adjustment distribution of oil and gas in the later stage. The oil bearing property of Chang 82 is poorer than that of Chang 81 because the Type II reservoirs in Chang 82 are more developed， and strong carbonate cementation reduces the connectivity of pore throats， which is not conducive to oil and gas charging.

HU Junjie, LU Cong, GUO Jianchun, ZENG Bo, GUO Xingwu, MA Li, SUN Yuduo

With technological advancements, fibers now serve roles beyond proppant backflow prevention, including proppant transport, plugging, fracture morphology optimization, and other aspects, namely, fiber-network proppant fracturing technology. The fiber-based proppant transport and fiber temporary plugging technologies can effectively address issues currently faced by deep shale gas, such as proppant near-wellbore accumulation and insufficient temporary plugging effectiveness, thereby improving the effectiveness of volumetric fracturing stimulation. To this end, the study was conducted in a deep shale gas block in the southern Sichuan Basin, investigating fiber-based proppant transport and fiber temporary plugging mechanisms, as well as laboratory physical simulations to optimize and evaluate the performance of fiber materials. Based on the regional geological and engineering characteristics of the study area, fracturing software simulations were carried out to determine the hydraulic fracture width for deep shale gas. A field test plan was then developed, and the fracturing construction, flowback, plugging, and fracturing effectiveness of the test wells were monitored and evaluated. The research results indicated that fibers had strong proppant transport assistance and flexible bridging capabilities. By modifying the molecular structure of fiber materials and adding a certain amount of structural stabilizers, discontinuous cluster-like support structures can be formed, significantly enhancing the placement effect and conductivity of proppants. Based on fracture width simulation calculations, the hydraulic fracture width for deep shale gas is between 2 to 5 mm. By optimizing fiber types based on fracture width, proppant grain size, and concentration, full support of fractures can be achieved. Compared to conventional fracturing wells, the test wells with modified fiber + structural stabilizer for sand-carrying fracturing exhibited better production increase and proppant flowback prevention. Fibers can be used for temporary in-fracture plugging. During the construction process, the pressure response is evident, which may lead to excessively high pressure during subsequent operations, making proppant addition difficult. Optimizing the timing of fiber injection is beneficial for the subsequent overall sand addition process. Additionally, fibers can also be used to address the inter-well gas migration issue in deep shale gas wells by strengthening the temporary plugging of fracture openings and sealing natural fractures, thereby preventing further communication between hydraulic fractures and distant natural fractures. The study, based on the characteristics of deep shale reservoirs in the southern Sichuan Basin, has developed a set of performance indicators for fiber materials suitable for deep shale gas, including fiber length, stability, compatibility, and degradation rate. It also proposes a four-in-one fiber injection process and design method, focusing on “entry, distance, height, and prevention”. It provides strong support for the future economic development, technology optimization, and fracturing process adjustments of shale gas.

Vraj Shah, Bhavin Panchal, Catherine Gona et al.

Evan Patterson

Products in double categories, as found in cartesian double categories, are an elegant concept with numerous applications, yet also have a few puzzling aspects. In this paper, we revisit double-categorical products from an unbiased perspective, following up an original idea by Paré to employ a double-categorical analogue of the family construction, or free product completion. Defined in this way, double categories with finite products are strictly more expressive than cartesian double categories, while being governed by a single universal property that is no more difficult to work with. We develop the basic theory and examples of such products and, by duality, of coproducts in double categories. As an application, we introduce finite-product double theories, a categorification of finite-product theories that extends recent work by Lambert and the author on cartesian double theories, and we construct the virtual double category of models of a finite-product double theory.

Serge Gratton, Chee-Khian Sim, Philippe L. Toint

We revisit the standard ``telescoping sum'' argument ubiquitous in the final steps of analyzing evaluation complexity of algorithms for smooth nonconvex optimization, and obtain a refined formulation of the resulting bound as a function of the requested accuracy $ε$. While bounds obtained using the standard argument typically are of the form $\mathcal{O}(ε^{-α})$ for some positive $α$, the refined results are of the form $o(ε^{-α})$. We then explore to which known algorithms our refined bounds are applicable and finally describe an example showing how close the standard and refined bounds can be.

WANG Yu, LIU Yulong, QIU Dekun et al.

To increase the penetration performance of perforating bullet, the powder particle grade technique is studied by increasing the density of tungsten powder liner. By using the method of geometric configuration analysis and the effect of cramming and cladding between the big and small particles, an idealized particle grading model considering the morphology of tungsten powder particles is constructed. The compact density formula of the packing system formed by the interaction of large and small tungsten powder particles and the relation formula of each parameter are obtained. Tungsten powder particle grading technology is applied to make the tungsten powder liner of perforating, and the bulk density of tungsten powder and density of the liner are tested. The result shows that the the bulk density of tungsten powder is increased from 7.96 g/cm3 to 9.65 g/cm3 with a growth rate of 21.2%. The density of perforating liner is increased from 14.70 g/cm3 to 15.69 g/cm3 with a growth rate of 7.6%. This has fully proved that the particle grade model is right and the tungsten powder partical grade has prominent effect on density increasment of the liner of perforating. The tungsten powder partical grade has been proved an effective method to increase the performance of perorating bult.

Rafael F Perez, I. C. Santos, Vitor P. Macedo et al.

In petroleum production, silicone oil (polydimethylsiloxane or PDMS) remains the most efficient product for combating foam, despite its negative effects on petroleum contamination and catalytic refining processes. This study aimed to evaluate the defoaming action of silicone oils with varying molar masses (ranging from 3 to 110 kg·mol−1) as defoamers in crude oils with different densities (20, 26, and 30°API). The results were correlated with the dilatational rheology obtained through pendant drop tensiometry of the oil samples. The silicone samples were characterized using gel permeation chromatography and thermogravimetric analysis, while the petroleum samples underwent SARA (saturated, aromatics, resins, asphaltenes) composition analysis, density measurement, and assessment of water content. The PDMS range of 8 to 30 kg·mol−1 exhibited enhanced antifoaming efficiency for the tested oils. A plateau in efficiency was observed when antifoamers were dosed above 15 ppm. Additionally, a reverse relationship between the initial formation of foam and the elastic modulus (G') of the oil in the presence of the antifoamer was observed, suggesting that the more effective antifoamer actually increased the elasticity of the film.

Jikun Liu, Litao Wang, Fei Chen et al.

The progress in ultrahigh-resolution mass spectrometry (UHRMS) and related technologies has significantly promoted the development of petroleomics. The study of petroleomics has greatly broadened our knowledge of the composition of petroleum at the molecular level, especially heavy fractions that cannot be analyzed by gas chromatography (GC)-based methods. To date, heteroatom-containing (O, N, S, and metal atoms) compounds in petroleum have been studied extensively by UHRMS. Nevertheless, the main components of petroleum, hydrocarbon compounds, have remained out of reach of petroleomics characterization for a long time because they are too difficult to be softly and efficiently ionized for UHRMS analysis. It is undoubtedly the case that petroleum hydrocarbons should not be the missing part of petroleomics characterization since they play important roles not only as feeding pools for various high value-added petroleum products but also as critical biomarkers for geochemistry studies. Here, the most recent breakthroughs in petroleomics characterization of hydrocarbon compounds using UHRMS rather than conventional methods have been reviewed. Innovations of soft ionization methods can transform non-polar hydrocarbon molecules into molecular ions or quasi-molecular ions that are reachable for UHRMS without fragmentation. The development of data processing methods has assisted the decoding of the complicated UHRMS data to visualize the molecular composition and structure of hydrocarbon compounds. These advances make it possible to see the whole picture of petroleum compositions, from light distillation fractions to heavy distillation fractions, and from small volatile molecules to large non-volatile ones. The applications of UHRMS-based methods for petroleomics characterization of hydrocarbon compounds in crude oils and various petroleum samples including fuel oil, slurry, and even asphaltene have made a great contribution to petrochemistry and geochemistry studies, especially in the fields of molecular refining and biomarker discovery.

Yao Jiang, Junyu Guo, Ying Zhou et al.

Methylsiloxanes (MSs) are widely used in industrial production and have attracted much attention due to their potential health risks to humans. MSs are present in emissions from petroleum refining, and it is therefore important to assess the health risks to residents living near refineries. In this study, we evaluated the pollution characteristics and human exposure risks of three cyclic MS (CMS) oligomers (D4-D6) in areas upwind and downwind of a petroleum refinery. The concentrations of total CMSs were 4-33 times higher in the downwind than upwind areas. At the same sampling site, the concentrations of CMSs were higher indoors than outdoors. The maximum concentration of CMSs was found in the indoor environment 200 m downwind of the petroleum refinery (75 μg/m3 in air and 2.3 μg/g in dust). The concentrations and detection rates of CMSs in plasma samples were higher in the downwind than upwind residents. Although residents living downwind of the petroleum refinery were a non-occupationally exposed population, they should be considered a highly CMS-exposed population because of their extremely high internal exposure doses. Inhalation exposure was the main source of CMSs in the plasma of these residents. When different exposure pathways were investigated, inhalation exposure was the major contributor to the average daily dose in residents of locations near the petroleum refinery, whereas the dermal absorption of personal care products was the major contributor at other sites. Although the overall risks of exposure to total CMSs were below the chronic reference dose for all exposure pathways, the combined joint toxic effects of various CMSs remain unclear. Further studies are therefore required to determine the exposure risks and subsequent health effects of CMSs for the residents of these areas.

Sajad Mousavi, Ricardo Luna Gutiérrez, Desik Rengarajan et al.

We propose a self-correction mechanism for Large Language Models (LLMs) to mitigate issues such as toxicity and fact hallucination. This method involves refining model outputs through an ensemble of critics and the model's own feedback. Drawing inspiration from human behavior, we explore whether LLMs can emulate the self-correction process observed in humans who often engage in self-reflection and seek input from others to refine their understanding of complex topics. Our approach is model-agnostic and can be applied across various domains to enhance trustworthiness by addressing fairness, bias, and robustness concerns. We consistently observe performance improvements in LLMs for reducing toxicity and correcting factual errors.

Ahmed Farid Ibrahim, Ruud Weijermars

Abstract Accurate estimation of fracture half-lengths in shale gas and oil reservoirs is critical for optimizing stimulation design, evaluating production potential, monitoring reservoir performance, and making informed economic decisions. Assessing the dimensions of hydraulic fractures and the quality of well completions in shale gas and oil reservoirs typically involves techniques such as chemical tracers, microseismic fiber optics, and production logs, which can be time-consuming and costly. This study demonstrates an alternative approach to estimate fracture half-lengths using the Gaussian pressure transient (GPT) Method, which has recently emerged as a novel technique for quantifying pressure depletion around single wells, multiple wells, and hydraulic fractures. The GPT method is compared to the well-established rate transient analysis (RTA) method to evaluate its effectiveness in estimating fracture parameters. The study used production data from 11 wells at the hydraulic fracture test site 1 in the Midland Basin of West Texas from Upper and Middle Wolfcamp (WC) formations. The data included flow rates and pressure readings, and the fracture half-lengths of the 11 wells were individually estimated by matching the production data to historical records. The GPT method can calculate the fracture half-length from daily production data, given a certain formation permeability. Independently, the traditional RTA method was applied to separately estimate the fracture half-length. The results of the two methods (GPT and RTA) are within an acceptable, small error margin for all 5 of the Middle WC wells studied, and for 5 of the 6 Upper WC wells. The slight deviation in the case of the Upper WC well is due to the different production control and a longer time for the well to reach constant bottomhole pressure. The estimated stimulated surface area for the Middle and Upper WC wells was correlated to the injected proppant volume and the total fluid production. Applying RTA and GPT methods to the historic production data improves the fracture diagnostics accuracy by reducing the uncertainty in the estimation of fracture dimensions, for given formation permeability values of the stimulated rock volume.

A. Lapin

In the article, the author analyzes the emerging transition of the country's oil industry to the mobilization type under the conditions of sanctions, examines the rapidly changing world market of oil and petroleum products. The subject of the study is the accelerated modernization of the oil industry, trends in the sale of Russian oil on the world market. The purpose of the article is to analyze the emerging anti–sanctions model of the development of the Russian oil industry and the export of oil and petroleum products on the basis of statistical data and an example of the development of vertically integrated oil companies, formulate recommendations to public administration bodies and business participants for the implementation of strategic plans of the state. Materials and methods. The methodological basis of the article consists of statistical methods, methods of analysis and synthesis for considering the role of the state in the development of vertically integrated oil companies, import substitution of the oil industry, systemic and structural-functional approaches for formulating proposals for the development of the Russian oil industry and the sale of Russian oil on the world market. Results. The analysis of statistical data on the extraction (production) and export of oil and petroleum products, the possibilities of stimulating mechanisms of the state are presented, proposals for further development and improvement of the oil industry are formulated. Conclusions. The results of the analysis of the process of transition of the country's oil industry to the mobilization type in the current conditions of sanctions and the activities of the state and business revealed the forced termination of cooperation with most developed countries in terms of oil and petroleum products exports and imports of equipment and technologies for oil production and refining. The proposals formulated by the author on the development of the oil industry will help minimize losses in the oil and petroleum products market and maintain the efficiency of oil industry enterprises. Application. The results obtained can be used to analyze trends in the development of the oil industry and the world market of oil and petroleum products.

S. Saha, Pritishma Lakhe, M. J. Mason et al.

Petroleum coke is a solid, carbonaceous by-product of oil refining and is normally used for heating or as an anode in aluminum and steel production. These applications contribute to carbon emissions, but here we show that petroleum coke has another potential avenue: as a precursor for graphene production. This path presents an environmentally and economically sustainable use for a low-value industrial stream. Electrochemical exfoliation is used to produce graphene nanosheets from petroleum coke, rather than graphite. The final product is separated from the unreacted material by a two-step centrifuging process. SEM and TEM images confirm that the final product contains few-layered nanosheets, and the Raman spectra confirm that the exfoliated coke product is indeed graphene. Post-annealing of this product substantially increases the electrical conductivity. This new finding holds potential for the petroleum industry to produce a value-added nanomaterial and enhance the economic impact of slurry oil and slurry oil-derived coke streams by orders of magnitude; this route also allows these streams to be directed away from high-emissions uses.

Yeye Liu, Shenglin Lu, Xuejun Yan et al.

Abstract Climate change mainly caused by transportation fuel consumption has attracted global concern. In life cycle environmental burdens generated from transportation fuel production, petroleum refining stage is the hotspot. However, the in-depth environmental analysis of petroleum refining is very limited. China is the second largest petroleum refining country, so it is very essential to break petroleum refining stage into specific unit to analyze how Chinese refinery can be improved in environment performance. To achieve this goal, a systematic life cycle analysis of the environmental burden generated from petroleum refining process was conducted to identify the control emphasis and seek potential improvement measures. Sensitive analysis and volatile organic compounds (VOCs) emission characteristics were additional discussed to improve the accuracy of results. The significant burdens generated from petroleum refining process were freshwater ecotoxicity and climate change. Crude oil extraction and transport dominated most environmental categories, which indicated that the environmental problem exist in upstream supply chain. Catalytic cracking, feedstock and product handling, catalytic reforming, crude oil distillation, cooling water system and diesel hydrotreating were the major control units due to their direct emissions and electricity consumption. VOCs (e.g., acrolein and chlorofluorocarbons) produced from refinery fugitive emissions were the main substances for refinery to reduce human toxicity, ozone depletion and photochemical oxidant formation influences. 14% of Climate change were derived from organic chemicals emission in this study, which suggested that VOCs-related carbon emission should be involved in current carbon accounting work or greenhouse gases (GHGs) studies on the petroleum refining industry. The identified control emphasis included equipment leaks from core refining units, storage tank emissions control, energy structure optimization and catalysts consumption intensity reduction. Some feasible and useful reduction measures targeted the control emphasis were proposed for policy makers and refinery managers to formulate reduction strategies and improve the sustainability of the petrochemical industry.