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It is well known that the existing horizontal-well-drilling and hydraulic fracturing technology used to achieve large-scale, cost-effective production from immature to low–moderate-maturity continental shale in China, where the organic matter mainly exists in solid form, is fairly ineffective. To overcome the obstacles, in situ conversion technology seems feasible, while implementing it in the target layer along with estimating the amount of expected recoverable hydrocarbon in such shale formations seems difficult. This is because there are no guidelines for choosing the most appropriate method and selecting relevant key parameters for this purpose. Hence, based on thermal simulation experiments during the in situ conversion of crude oil from the Triassic Chang 73 Formation in the Ordos Basin and the Cretaceous Nenjiang Formation in the Songliao Basin, this deficiency in knowledge was addressed. First, relationships between the in situ-converted total organic carbon (TOC) content and the vitrinite reflectance (Ro) of the shales and between the residual oil volume and the hydrocarbon yield were established. Second, the yields of residual oil and in situ-converted hydrocarbon were measured, revealing their sensitivity to fluid pressure and crude oil density. In addition, a model was proposed to estimate the amount of in situ-converted hydrocarbon based on TOC, hydrocarbon generation potential, Ro, residual oil volume, fluid pressure, and crude oil density. Finally, a method was established to determine key parameters of the final hydrocarbon yield from immature to low–moderate-maturity organic material during in situ conversion in shales. Following the procedure outlined in this paper, the estimated recoverable in situ-converted oil in the shales of the Nenjiang Formation in the Songliao Basin was estimated to be approximately 292 × 108 tons, along with 18.5 × 1012 cubic meters of natural gas, in an area of approximately 8 × 104 square kilometers. Collectively, the method developed in this study is independent of the organic matter type and other geological and/or petrophysical properties of the formation and can be applied to other areas globally where there are no available in situ conversion thermal simulation experimental data. [ABSTRACT FROM AUTHOR]

This paper presents the application of two versions of the multilayer fluidized bed made out of two materials with significantly different densities. The first type of fluidized bed was composed of raw cenospheres and quartz sand. The second type of fluidized bed was composed of cenospheres coated with iron oxides and quartz sand. A variable vertical density profiles in the prepared fluidized beds were confirmed, making them suitable for processing polymeric materials, specifically, polyolefins with a density below 1 g/cm3. The polyolefin pyrolysis process was investigated in both versions of the fluidized bed at temperatures of 520, 540, 560, and 590 °C. The products of the pyrolysis were monitored using high-resolution infrared spectroscopy (with a resolution of 1 cm−1). While the process is organized in these fluidized beds, the absence of the accumulation of solid residues is notable. The results show that the pyrolytic gaseous mixture is composed of numerous compounds, namely, unsaturated and saturated aliphatic hydrocarbons and benzene. The possibility of producing a gas rich in ethylene, propylene, and 1-butene during the pyrolysis was demonstrated. Additionally, during the pyrolysis of both polymers, the production of benzene was shown with yields, ranging from 5%wt. in the fluidized bed made out of raw cenospheres to 11 %wt. in the fluidized bed made out of cenospheres modified by iron oxides. Due to the complex nature of the resulting pyrolytic gas, it is suggested that we process the created gaseous mixtures entirely in a steam conversion process, making them a potential source of hydrogen. [ABSTRACT FROM AUTHOR]

Affected by Tianshan uplift, the southern Junggar Basin has experienced multi-stage tectonic movements and formed many large-scale anticlines with zonal distribution. The key to hydrocarbon exploration is to accurately implement anticline traps. This paper is guided by the fault-related folds theory to tectonically interpret several seismic profiles in the southern Junggar Basin and then summarize the anticline types and their hydrocarbon accumulation characteristics. This paper showed that the southern Junggar Basin has a tectonic assemblage pattern of "multi-detachment layers and multi-phase superposition". According to the superimposed shape of the anticlines, they could be divided into overthrust anticlines, compound anticlines and multiple superimposed anticlines, and the horizontal and vertical positions of the different types of anticlines are different. The hydrocarbon accumulating characteristics of the different types of anticlines are shown to be different. The highs of the overthrust anticlines and compound anticlines are stable, and the degree of exploration is relatively high. Although the degree of exploration of multiple overlapping anticlines is low, multiple layers can be exploited simultaneously in the process of oil development, with great hydrocarbon potential. The characteristics of hydrocarbon accumulation in the southern Junggar Basin are discussed in order to provide guidance for efficient hydrocarbon exploration. [ABSTRACT FROM AUTHOR]

Unsaturated hydrocarbons are major components of transportation fuels, combustion intermediates, and unburnt exhaust emissions. Conversely, NOx species are minor species present in the residual and exhaust gases of gasoline-fueled engines and gas turbines. Their co-existence in transportation engines is quite common, particularly with exhaust gas recirculation, which can greatly influence engine combustion characteristics. Therefore, this paper presents a review on the combustion chemistry of unsaturated hydrocarbons and NOx mixtures, with a focus on their chemical kinetic interactions. First, a comprehensive overview of fundamental combustion experiments is provided, covering mixtures of C2–C5 unsaturated/oxygenated species (namely alkenes, alkynes, dienes, alcohols, ethers, ketones, and furans) and three major NOx species (namely NO, NO2, and N2O), as well as reactors including jet-stirred reactors, flow reactors, burners, shock tubes, and rapid compression machines. Then, two widely adopted nitrogen chemistry models are evaluated in conjunction with a core chemistry model (i.e., NUIGMech1.1) via detailed chemical kinetic modeling, and the model similarities and differences across broad temperature ranges are highlighted. Thereafter, the unique interconversions between the three major NOx species are presented. In particular, the controversy regarding the pathways governing NO and NO2 conversion is discussed. Following this, the key direct interaction reactions between unsaturated species and NOx species are overviewed. Finally, the distinguishing features of the combustion chemistry for unsaturated hydrocarbon and NOx mixtures are summarized, and recommendations for future research on this topic are highlighted. [ABSTRACT FROM AUTHOR]

Transitional shale gas, rich in resources, is expected to be a practical contributor to the increase in shale gas reserves and production in China. Its exploration prospect has been demonstrated by several wells in the Daning-Jixian block on the eastern margin of the Ordos Basin. In this paper, the Lower Permian Shanxi Formation (P1s) and Taiyuan Formation (P1t) in the eastern margin of Ordos Basin were compared for organic geochemical parameters, revealing that the overflow fan + lagoon combination (OLC) of the third sub-member of the second member of Shanxi Formation (P1s23) and the marine + lagoon combination (MLC) of the first member of Taiyuan Formation (P1t1) are the most favorable shale gas intervals. The two intervals were comparatively analyzed with respect to mineral composition, brittleness, caprocks, and preservation conditions. It is found that the OLC of P1s23 has a similar porosity to and much lower permeability than the MLC of P1t1 (or MLC1) and a BET surface area of 10–15 m2/g, which is smaller than the MLC1 (15–20 m2/g). Moreover, OLC has a brittle mineral content equivalent to MLC1 but a brittleness index of 33.73–62.36 (avg. 49.86), smaller than MLC1 (53.34–58.27, or avg. 55.85). OLC contains sandstones at both the roof and floor, with a higher permeability than shale in the interval, which cannot serve as good physical seals. In contrast, MLC1 contains limestones with lower permeability at the roof and floor, which, together with the overlying coal seams, have hydrocarbon generation capacity and can physically seal the MLC1 shale but also fill it with hydrocarbons, making MLC1 have higher gas content and superior for shale gas exploration than the OLC shale. Due to the multi-lithologies developed in transitional facies, besides the organic matter enrichment, and reservoir characteristics, it is necessary to find a suitable lithological combination to ensure the gas in shale can be better preserved and retained. [ABSTRACT FROM AUTHOR]

In the process of diagenesis and burial of sedimentary basins, basin fluid activities participate in the process of hydrocarbon accumulation and metal mineralization. Understanding the evolution of basin fluid is of great significance in revealing the related hydrocarbon accumulation and mineralization. Paleo-reservoirs are closely associated with Carlin-type gold deposits in the Nanpanjiang-Youjiang Basin, South China. Calcite, the fluid activity product, is closely related to bitumen and gold-bearing pyrite. By integrating petrographic, cathode luminescence, and fluid inclusion analysis, as well as the relevant chronological results of predecessors, this paper attempts to establish the relationship between fluid evolution, hydrocarbon accumulation, and gold mineralization. Two types of calcite (black/gray and white) developed in the Banqi-Yata-Laizishan area, the Nanpanjiang-Youjiang Basin. Black/gray calcite is symbiotic with bitumen and features dark red colors in cathode luminescence. Many hydrocarbon inclusions developed along with fluid inclusion analysis at low homogenization temperatures (65.7~173.1 °C). Combining the previously reported U-Pb ages (~250–230 Ma) of this kind of calcite with some geochemistry data on the associated reservoir and gold deposit, this calcite records the consecutive hydrocarbon accumulation and Carlin-type gold mineralization from the Late Permian to the Late Triassic periods controlled by Indosinian tectonic movement. The white calcite featuring bright red in cathodoluminescence is symbiotic with gold-bearing pyrite and realgar, and the associated fluid inclusions have high homogenization temperatures (128.2~299.9 °C). Combined with regional tectonic background and isotopic chronology (~140–106 Ma), it seems to record the early Cretaceous Carlin-type gold mineralization controlled by the subduction of the paleo-Pacific plate in the late Yanshanian period. [ABSTRACT FROM AUTHOR]

Ecosystem destruction is one of today's significant challenges due to fast industrialisation and an increasing population. It takes several years for solid trash, such as plastic bottles and super-market bags, to decompose in nature. In addition, plastic disposal techniques such as landfilling, reuse, and incineration pose significant threats to human health and the environment. In this paper, we investigated whether the impact of mixing biodiesel with waste oil from recycled plastic on the resulting fuel mixture's yields better physical and chemical properties. Consequently, pyrolysis is one of the most advantageous and practical waste disposal methods as it is both environmentally benign and efficient. Pyrolysis is the high-temperature thermal breakdown of solid waste to produce pyrolytic oil. The pyrolytic (plastic) oil produced is converted to a hydrocarbon-rich pyrolytic fuel. Similar to diesel and gasoline, pyrolytic fuel has the same calorific value. Internal combustion engines may operate on pyrolytic fuel without suffering a performance reduction. Researchers examined engine performance and exhaust pollutants. The research discovered that the engine could operate on plastic pyrolysis fuel at full load, enhance brake thermal efficiency by 6–8%, and lower UBHC and CO emissions; however, nitrous oxide (NOx) emissions were noticeably higher. The findings demonstrated the possibility of using plastic pyrolysis fuel as a diesel substitute. [ABSTRACT FROM AUTHOR]

Keywords: geothermal energy; repurposing hydrocarbon wells; UK resource assessment EN geothermal energy repurposing hydrocarbon wells UK resource assessment 6382 1 12/17/20 20201201 NES 201201 Reply: Monaghan, Manning, and Shipton [[1]] allege 'factual inaccuracies around the purpose of the UK Geoenergy Observatory in Glasgow (GGERFS)' in the I Energies i paper by Watson et al. [[2]]. The aim of the Watson et al. paper [[2]] was to assess potential (theoretical) heat outputs of onshore hydrocarbon wells in Britain if repurposed for geothermal heat production. In any case, itemisation of the overall GGERFS budget is immaterial to the results and conclusions of Watson et al. [[2]] and there cannot be any cause of misunderstanding by future GGERFS users, given the previously cited statement in [[2]] that 'the GGERFS is a test site for minewater geothermal heat production and is not currently used for heat production or storage', with due citation of GGERFS open reports (e.g., [[6], [10]]). [Extracted from the article]

In Beijing, China, the rational consumption of energy is affected by the insufficient linkage mechanism of the energy pricing system, the unreasonable price ratio and other issues. This paper combines the characteristics of Beijing's energy market, putting forward the society-economy equilibrium indicator R maximization taking into consideration the mitigation cost to determine a reasonable price ratio range. Based on the computable general equilibrium (CGE) model, and dividing four kinds of energy sources into three groups, the impact of price fluctuations of electricity and natural gas on the Gross Domestic Product (GDP), Consumer Price Index (CPI), energy consumption and CO2 and SO2 emissions can be simulated for various scenarios. On this basis, the integrated effects of electricity and natural gas price shocks on the Beijing economy and environment can be calculated. The results show that relative to the coal prices, the electricity and natural gas prices in Beijing are currently below reasonable levels; the solution to these unreasonable energy price ratios should begin by improving the energy pricing mechanism, through means such as the establishment of a sound dynamic adjustment mechanism between regulated prices and market prices. This provides a new idea for exploring the rationality of energy price ratios in imperfect competitive energy markets. [ABSTRACT FROM AUTHOR]

Propylene and acetylene are released to mine air with the increase in the temperature of self-heating coal. Concentrations of these gases in mine air are applied as indicators of the progress of the self-heating process. Hydrocarbons emitted from the self-ignition center are sorbed on coal, while migrating through the mine workings. Coal crushed during the mining process is characterized by a high sorption capacity, which facilitates the sorption phenomena. This results in the decrease in hydrocarbons content in mine air, and in the subsequent incorrect assessment of the development of the self-heating process. The results of the experimental study on propylene and acetylene sorption on Polish coals acquired from operating coal mines are presented in this paper. Bituminous coal is characterized by a high sorption capacity with respect to unsaturated hydrocarbons, like propylene and acetylene. The sorbed volumes depend on the grade of metamorphism, porosity, and chemical characteristics of coal. Low level of metamorphism, increased porosity, and oxygen content result in higher sorption capacity of coals. The reduction in grain size of coals also results in the increased sorption capacity with respect to hydrocarbons. The most significant increase in the volumes of sorbed propylene and acetylene with the decrease in grain class was observed for coals of low porosity, high grade of metamorphism, and low to medium sorption capacities. The 10-fold decrease in coal grain size resulted in the 3 to 6-fold increase in the volume of sorbed propylene, and 2-fold increase for acetylene. The decrease in grain size results in higher accessibility of pore structure, increased pore volume and area, and higher number of active centers interacting with hydrocarbons of dipole characteristics. For coals with low grade metamorphism, high porosity, and high sorption capacity the volumes of sorbed propylene and acetylene increased only slightly with the decrease in coal grain size. [ABSTRACT FROM AUTHOR]

In this work, a previously developed three-feature Artificial Neural Network (ANN) model with dimensional inputs is directly applied to predict the cell size of hydrocarbon/ammonia/nitrous oxide mixtures and compare these to experimental data. This model uses as inputs three ZND parameters (MCJ, ΔI, and σ ˙ max ), which are mainly calculated using Konnov's and Mével's mechanisms. A similar prediction is obtained with the two mechanisms for the biogas–O2, H2–O2, H2–N2O, and NH3–O2 mixtures, indicating that the model is not only limited to Konnov's chemical kinetic mechanism which was used for its training. The overall good agreement between the ANN predictions and the actual experimental values for the aforementioned mixtures, which are not used in the original training of the ANN model, is promising and shows its potential for application and extension to other mixtures and initial conditions, provided that the chemical kinetic parameters describing the ideal reaction zone structure could be computed. The model is then used to compare experimental cell size data from two detonation tube facilities, and also different chemical kinetic mechanisms for NH3-N2O mixtures. In the end, the original ANN model is expanded with the inclusion of additional cell size data, showing a slightly lower mean error for the predicted cell sizes if the data for the mixtures considered in this study are taken into account for the training of the new ANN model. [ABSTRACT FROM AUTHOR]

Geothermal energy is one of the cleanest sources of energy which is gaining importance as an alternative to hydrocarbons. Geothermal energy reserves in China are enormous and it has a huge potential for exploitation and utilization. However, the development of the geothermal industry in China lags far behind other renewable energy sources because of the lack of fiscal and taxation policy support. In this paper, we adopt the system dynamics method and use the causal loop diagram to explore the development mechanism of fiscal and taxation policies in the geothermal industry. The effect of the fiscal and taxation policy on the development of the geothermal industry is analyzed. In order to promote sustainable development of the geothermal industry in China, the government should pay more attention to subsidies for the geothermal industry in the life-cycle stage of the geothermal industry. Furthermore, a plan is necessary to provide a reasonable system of fiscal and taxation policies. [ABSTRACT FROM AUTHOR]

In recent years, many oil and gas fields have been discovered in ultra-deep sea (UDS). Some of these fields are evaluated to have no commercial value if existing oil field development approaches are used, especially while the oil prices remain low. A new alternative field development solution, termed as Subsurface Well Completion (SWC) system, is proposed with the aim to produce oil and gas in a cost-effective manner in UDS. This system primarily consists of four parts: a tethered subsurface platform, the rigid riser, SWC equipment and flexible jumper. Obviously, central to the evaluation and application of the new SWC technology is the inherent risk relative to acceptance level. In particular, an uncontrolled release of hydrocarbons to sea, which may lead to catastrophical consequences involving personnel risk, environmental damage and economic losses, is a main contributor to the total risk and of great concern to the offshore petroleum industry. As for the new SWC system, any failure will not be a direct source of risk for the personnel on the surface installation due to its offset feature. In this context, this paper proposes a quantitative risk assessment (QRA) framework to assess such uncontrolled releases to sea with regard to the SWC system for an oil field in the production phase based on the new Subsurface Tension Leg Production (STLP) facility. According to the QRA results presented in this paper, the identified scenarios representing uncontrolled releases to sea are subsea wellhead leaks, rigid riser leaks, subsurface wellhead leaks, releases from X-mas tree and flexible jumper leaks. Among these scenarios, subsea wellhead is found to be the high-risk area. Compared with the established risk acceptance criteria (RAC), the environmental risk levels for the subsea wellhead's leak lie within the As Low As Reasonably Practicable (ALARP) region while other risks are all below ALARP limits, which means that there is a need for improved consideration of the existing design with regard to the subsea wellhead area, and the corresponding risk reduction measures are proposed. Furthermore, the sources and effects of uncertainties are reviewed and sensitivity studies are carried out to illustrate the effect of some of the important assumptions in the risk model. It can be found that some assumptions made are conservative or optimistic while others are unknown. However, the final QRA results can be regarded as somewhat conservative. This paper concludes that the new SWC technology has a distinct advantage with respect to the leakage duration time in UDS, and thus mitigates the environmental and commercial impacts to a large extent. Besides, relaxed design requirements for the X-mas tree and flexible jumper can be accepted. It is also concluded that there are no serious and major commercial losses for all the identified accidental release scenarios, which is of great importance and attractiveness to oil producers. [ABSTRACT FROM AUTHOR]

This paper introduces a new iterative method to predict the equivalent centrifugal compressor performance at various operating conditions. The presented theoretical analysis and empirical correlations provide a novel approach to derive the entire compressor map corresponding to various suction conditions without a prior knowledge of the detailed geometry. The efficiency model was derived to reflect the impact of physical gas properties, Mach number, and flow and work coefficients. One of the main features of the developed technique is the fact that it considers the variation in the gas properties and stage efficiency which makes it appropriate with hydrocarbons. This method has been tested to predict the performance of two multistage centrifugal compressors and the estimated characteristics are compared with the measured data. The carried comparison revealed a good matching with the actual values, including the stable operation region limits. Furthermore, an optimization study was conducted to investigate the influences of suction conditions on the stage efficiency and surge margin. Moreover, a new sort of presentation has been generated to obtain the equivalent performance characteristics for a constant discharge pressure operation at variable suction pressure and temperature working conditions. A further validation is included in part two of this study in order to evaluate the prediction capability of the derived model at various gas compositions. [ABSTRACT FROM AUTHOR]

The distribution characteristics and main controlling factors of hydrocarbon phases in deep strata from petroliferous basins are important for the evaluation of oil–gas resources and decision-making regarding exploration. The distribution characteristics and controlling factors of the Ordovician hydrocarbon phases are systematically analyzed in the Tazhong I block, Tarim Basin, NW China. The results show that the Ordovician reservoirs in the Tazhong I block are characterized as multi-phase reservoirs with a lateral co-existence of condensates, normal oil reservoirs, and heavy oil reservoirs. From east to west, gas-rich in the fault belt and oil-rich in the platform area are presented. Meanwhile, there are regular variations in the geochemical characteristics of the Ordovician hydrocarbon, showing decreasing trends in the gas/oil ratio (GOR), wax contents, dryness coefficients, methane contents, and methane carbonate isotope values (δ13C1) and an increasing trend in oil densities. Because the same Cambrian–Lower Ordovician source for the Ordovician hydrocarbon is observed in the Tazhong I block, the regular variations in the hydrocarbon phases and geochemical characteristics can be interpreted as records of gas invasion, biodegradation, multi-stage filling, thermal cracking, and thermochemical sulfate reduction (TSR) rather than controlled by the source rock organofacies. This indicated that different kinds of secondary processes for a diversity of the hydrocarbon phase can appear in one region. Our re-construction of the Ordovician hydrocarbon accumulation model in the Tazhong I block encourages future exploration to target gas reservoirs in the fault belt and oil reservoirs in the platform area. [ABSTRACT FROM AUTHOR]

Clarification of the cause of overpressure is of great significance for the study of hydrocarbon generation, migration and accumulation processes under an overpressure environment, and the prediction of predrilling pressure. The cause of overpressure in Xihu Depression is still controversial. This study, based on mudstone compaction research and organic matter correction of logging data, ascertained the causes of overpressure in the Pinghu tectonic zone, Xihu Depression. A modified discrimination method for overpressure genesis was used and the overpressure–hydrocarbon distribution relationship was explored. The results show the following: (1) Vertically, overpressure is located in the lower section of the Pinghu Formation, with a pressure coefficient of 1.1–1.7 and a pressure relief feature. On the plane, the pressure coefficient in the Pingzhong area exceeds that in the Pingbei area. (2) The main causes of abnormal high pressure in the research area are undercompaction and fluid expansion. The fluid expansion mechanisms include overpressure transmission and hydrocarbon charging within the reservoir as well as hydrocarbon generation pressurisation and overpressure transmission within the source rock. (3) In the surge section of kaolinite, under fluid pressure, kaolin migrates toward the low-pressure areas, decreasing the porosity in low-pressure areas and preserving pores in high-pressure areas. The evolution of fluid pressure can be divided into two stages: pressurisation; and both pressurisation and pressure relief. Pressurisation and pressure relief drive hydrocarbon charging, but hydrocarbons are more enriched in overpressure layers. [ABSTRACT FROM AUTHOR]

Most of the pumps working under two phase flows conditions are used in petroleum industry applications, like electrical submersible pumps (ESP) for hydrocarbon fluids, in chemistry, nuclear industries and in agriculture for irrigation purposes as well. Two-phase flows always deteriorate overall pump performances compared with single flow conditions. Several papers have been published aiming to understand flow physics and to model all the main mechanisms that govern gas pocket formation and surging phenomena. These mechanisms depend on the pump type, the impeller geometry, the rotational speed, design and off-design liquid flow rate conditions, the volumetric gas fraction, the fluid properties and the inlet pressure. In the present paper, a review on two phase performances from various centrifugal pumps designs is presented, mainly based on experimental results. The main focus is devoted to detect the significant geometrical parameters that: (1) Modify the pump head degradation level under bubbly flow regime assumption; (2) Allow single stage centrifugal pumps keep working under two-phase flow conditions with high inlet void fraction values before pump shut down, whatever the pump performance degradations and liquid production rates should be. Because most of the published experimental studies are performed on dedicated laboratory centrifugal pump models, most of the present review is based on air-water mixtures as the working fluid with inlet pressures close to atmospheric conditions. The following review supposes that gas phase is considered as a non-condensable perfect gas, while the liquid phase is incompressible. Both phases are isolated from external conditions: neither mass nor heat transfer take place between the phases. [ABSTRACT FROM AUTHOR]

In the last decade, exploration for unconventional hydrocarbon (shale gas) reservoirs has been carried out in Poland. The drilling of wells in prospective shale gas areas supplies numerous physicochemical measurements from rock and reservoir fluid samples. The objective of this paper is to present the method that has been developed for finding similarities between individual geological structures in terms of their hydrocarbon generation properties and hydrocarbon resources. The measurements and geochemical investigations of six wells located in the Ordovician, Silurian, and Cambrian formations of the Polish part of the East European Platform are used. Cluster analysis is used to compare and classify objects described by multiple attributes. The focus is on the issue of generating clusters that group samples within the gas, condensate, and oil windows. The vitrinite reflectance value (Ro) is adopted as the criterion for classifying individual samples into the respective windows. An additional issue was determining other characteristic geochemical properties of the samples classified into the selected clusters. Two variants of cluster analysis are applied—the furthest neighbor method and Ward's method—which resulted in 10 and 11 clusters, respectively. Particular attention was paid to the mean Ro values (within each cluster), allowing the classification of samples from a given cluster into one of the windows (gas, condensate, or oil). Using these methods, the samples were effectively classified into individual windows, and their percentage share within the Silurian, Ordovician, and Cambrian units is determined. [ABSTRACT FROM AUTHOR]

Light olefins are the main building blocks used in the petrochemical and chemical industries for the production of different components such as polymers, synthetic fibers, rubbers, and plastic materials. Currently, steam cracking of hydrocarbons is the main technology for the production of light olefins. In steam cracking, the pyrolysis of feedstocks occurs in the cracking furnace, where hydrocarbon feed and steam are first mixed and preheated in the convection section and then enter the furnace radiation section to crack to the desired products. This paper summarizes olefin production via the steam cracking process; and the reaction mechanism and cracking furnace are also discussed. The effect of different operating parameters, including temperature, residence time, feedstock composition, and the steam-to-hydrocarbon ratio, are also reviewed. [ABSTRACT FROM AUTHOR]

Solid oxide fuel cells (SOFCs)' main advantage in fuel flexibility appears to be an interesting subject for further exploration. From the literature survey, direct utilisation of hydrocarbon as fuel for SOFCs has garnered attention with promising results reported. Various approaches, showcasing potential for using methane (CH4) and heavier hydrocarbons in SOFCs, have been described. The direct use of hydrocarbons can occur through either direct internal reforming or gradual internal reforming, with requisite precautionary measures to mitigate carbon formation. While the internal reforming process could proceed via steam reforming, dry reforming or partial oxidation, an exciting development in the direct use of pure hydrocarbons, seems to progress well. Further exploration aims to refine strategies, enhance efficiency and ensure the long-term stability and performance of hydrocarbon-fuelled SOFC systems. This review delves into the progress in this field, primarily over the past two decades, offering comprehensive insights. Regardless of fuel type, studies have largely concentrated on catalyst compositions, modifications and reaction conditions to achieve better conversion and selectivity. Finding suitable anode materials exhibiting excellent performance and robustness under demanding operating conditions, remains a hurdle. Alternatively, ongoing efforts are directed towards lowering working temperatures, enabling consideration of a wider range of materials with improved electrochemical performance. [ABSTRACT FROM AUTHOR]

Two representative organic-rich mudstones from the Middle Permian (MP) and the Upper Carboniferous (UC) around the Fukang Depression in the Junggar Basin were selected to study and compare the pyrolysis behavior and kinetics. The MP and UC were described as type I and type II kerogen, respectively. The FTIR and XRD results revealed that the MP contains carbonates and different clay minerals compared to the UC. Peak deconvolution was used for the UC to delineate the pyrolysis process to better understand and compare the similarities and differences in the pyrolysis kinetics of the two mudstones. In addition, the Coats-Redfern method was employed to further differentiate the reaction stages based on the differences in the reaction models during pyrolysis. The kinetic results revealed that the activation energy, pre-exponential factors, and reaction models of the two mudstones have some similarities and differences. Combined with the analysis of the pyrolysis volatiles, the UC sample can release more CH4, CO, CO2, and aromatic hydrocarbon compounds at high temperatures, indicating that the UC has more oxygen-containing functional groups and aromatics, while the MP has more aliphatics. Through the above studies, the pyrolysis kinetics and mechanism of two organic-rich rocks could be clarified, guiding their development and efficient utilization. [ABSTRACT FROM AUTHOR]

In order to study the distribution pattern of hydrocarbons in the shallow layer of the slope area outside of the source in the hydrocarbon-bearing basin, we built a method to predict the favorable site of the fault that adjusts hydrocarbon to the shallow layer in the slope area outside of the source based on the investigation of the mechanism of hydrocarbon adjustment along a conduit fault to a shallow layer. The predicted favorable site is found to be the overlapping area of three sites: the locations of the sand carrier with a lateral supply of hydrocarbon, the transport sites of conduit faults, and the hydrocarbon leakage parts of overlying regional mudstone seal rock. We applied the method in a case study of the favorable sites of the Zhaobei Fault that adjust the hydrocarbon from the lower sub-member within the first member of Shahejie Formation (Es1L) to the shallow Guantao Formation in the Qikou Sag of Bohai Bay Basin. Our prediction shows that the favorable sites are mostly located in the middle part of the Zhaobei Fault with very limited distribution in the east, which are conducive to the oil and gas supplied by the underlying sand carrier in the Es1L Formation to convergence and accumulation in the shallow Guantao Formation. This result is consistent with the distribution of the hydrocarbon in the Guantao Formation located in the middle parts of the Zhaobei Fault, proving that this method is feasible for the prediction of the favorable sites of the fault that adjust hydrocarbon to the shallow layer in the slope area outside of source. [ABSTRACT FROM AUTHOR]

Hydrocarbon exploration and production activities are basic to the functioning of the oil and gas industry, while concession contracts and fees are central concepts in the aforementioned activities. The authors consider several questions regarding these concepts, such as: what is the legislative, institutional, and fiscal framework in certain European countries regarding hydrocarbon exploration and production? What are the major differences between them? Finally, is there room for improvement of the framework in the Republic of Croatia? To answer these questions, the authors contacted some of the relevant institutions and accessed official government gazettes, institution websites, legal aggregators, journal articles, books, and different legal publications regarding the oil and gas industry for several European countries, namely the Kingdom of Norway, the Russian Federation, the Republic of Austria, and the Republic of Croatia. As a result, this paper presents an overview of legislation, institutions, concession contracts, taxes, and fees for each of the aforementioned countries. The authors conclude that the Republic of Croatia could benefit from applying some foreign solutions in its own legislative and fiscal framework, i.e., using a sliding scale for royalty calculation and simplifying some administrative procedures. [ABSTRACT FROM AUTHOR]

There are many oil and gas fields around the world where the vast number of wells have been abandoned or suspended, mainly due to the depletion of reserves. Those abandoned oil and gas wells (AOGWs) are often located in areas with a prospective geothermal potential and might be retrofitted to a geothermal system without high-cost drilling. In Poland, there are thousands of wells, either operating, abandoned or negative, that might be used for different geothermal applications. Thus, the aim of this paper is not only to review geothermal and petroleum facts about the Eastern Carpathian Foredeep, but also to find out the areas, geological structures or just AOGWs, which are the most prospective in case of geothermal utilization. Due to the inseparability of geological settings with both oil and gas, as well as geothermal conditionings, firstly, the geological background of the analyzed region was performed, considering mainly the autochthonous Miocene formation. Then, geothermal and petroleum detailed characteristics were made. In the case of geothermal parameters, such as formation's thickness, temperatures, water-bearing horizons, wells' capacities, mineralization and others were extensively examined. Considering oil and gas settings, insights into reservoir rocks, hydrocarbon traps and migration paths issues were created. Then, for evaluating geothermal parameters for specific hydrocarbon reservoirs, their depths were established based on publicly available wells data. Thereafter, the average temperatures for selected reservoirs were set. As the effect, it turned out that most of the deposits have average temperatures of 40/50 °C, nonetheless, there are a few characterized by higher (even around 80 °C) temperatures at reasonable depths. [ABSTRACT FROM AUTHOR]

This study will present a comprehensive review of the two-phase flow boiling heat transfer coefficient of hydrocarbons such as propane (R-290), butane (R-600), iso-butane (R-600a), and ethanol at various experimental conditions. Studying the multiphase flow heat transfer coefficient is crucial for many types of heat transfer equipment to achieve higher efficiency for more compact design and cost reduction. One reason we chose hydrocarbons as refrigerants in this study is that they are of an ozone depletion potential equal to zero (ODP = 0) and a deficient level of direct global warming potential (GWP = 3). Moreover, hydrocarbons' thermodynamic and thermophysical characteristics qualify them to be a strong candidate for more heat transfer applications, initially, by constructing a database for the working fluids using multiple existing experimental work. The current data that this study have collected for the flow boiling spans a wide range of parameters, such as mass flux, heat flux, operating pressure, saturation temperature, etc. Furthermore, by comparing the experimental multiphase heat transfer coefficient database with the anticipated values of each correlation, the prediction performance of 26 correlations found in the literature was assessed. This study allows the best prediction method to be selected based on the minimum deviation of predicted results from the experimental database provided based on the mean absolute error (MAE) calculated from the assessed correlations. The conclusions of such a study can also be helpful for developing more accurate correlation methods for these fluids and improving the prediction of their flow boiling characteristics. [ABSTRACT FROM AUTHOR]

The U.S. Department of Energy's Co-Optima initiative simultaneous focused on diversifying fuel sources, improving efficiency, and reducing emissions through using novel combustion strategies and sustainable fuel blends. For medium-duty/heavy-duty diesel engines, research in this area has led to the development of a multimode strategy that uses premixed charge compression ignition (PCCI) at low loads and conventional diesel combustion (CDC) at mid–high loads. The aim of this study was to understand how emissions were impacted when using PCCI instead of CDC at low loads and switching to an oxygenated biofuel blend. It provides a detailed speciation of the hydrocarbon (HC) and particulate matter (PM) emissions from a multimode medium-duty engine operating at low loads in PCCI and CDC modes and high loads in CDC. The effect of the oxygenated biofuel blend on emissions was studied at all three mode–load conditions using #2 ULSD and a bio-derived fuel (25% hexyl hexanoate (HHN)) blended in #2 ULSD. The PCCI mode effectively decreased NOx, total HC, and PM/PN emissions, with a substantial decrease in larger particles (≥50 nm). A PM/PN reduction was observed at high loads with the 25% HHN fuel. While the total HC emissions were not impacted by fuel type, the detailed HC analysis exposed changes in the HC's composition. [ABSTRACT FROM AUTHOR]

Global warming is an existential threat to humanity and the rapid energy transition, which is required, will be the defining social, political and technical challenge of the 21st century. Practical experience and research results of recent years have showed that our actions to cover the gap between real situation and aims of climate agreements are not enough and that improvements in climate policy are needed, primarily in the energy sector. It is becoming increasingly clear that hydrocarbon resources, which production volume is increasing annually, will remain a significant part of the global fuel balance in the foreseeable future. Taking this into account, the main problem of the current climate policy is a limited portfolio of technologies, focused on replacement of hydrocarbon resources with renewable energy, without proper attention to an alternative ways of decreasing carbon intensity, such as carbon sequestration options. This study shows the need to review the existing climate policy portfolios through reorientation to CO2 utilization and disposal technologies and in terms of forming an appropriate appreciation for the role of hydrocarbon industries as the basis for the development of CO2-based production chains. In this paper we argue that: (1) focusing climate investments on a limited portfolio of energy technologies may become a trap that keeps us from achieving global emissions goals; (2) accounting for greenhouse gas (GHG) emissions losses, without taking into account the potential social effects of utilization, is a barrier to diversifying climate strategies; (3) with regard to hydrocarbon industries, a transition from destructive to creative measures aimed at implementing environmental projects is needed; (4) there are no cheap climate solutions, but the present cost of reducing CO2 emissions exceeds any estimate of the social cost of carbon. [ABSTRACT FROM AUTHOR]

This study focused on Middle Permian Lucaogou Formation saline lake source rocks, utilizing a combination of biomarkers and hydrocarbon generation thermal simulation to analyze their biological compositions, depositional environments, and hydrocarbon generation potential. The Pr/Ph ratio, Ph/nC18 ratio, and Pr/nC17 ratio indicate that the Lucaogou Formation was in a reducing environment during the deposition period, and the lower part of the Lucaogou Formation (P2l1) is more anoxic than the upper part of the Lucaogou Formation (P2l2). The maturity index 20S (%) and ββ (%) reflect that the maturity of organic matter in the P2l1 is slightly higher than that in the P2l2. The G/H index and the ETR index indicate that the stratification of the water column is better during the sedimentary period of Lucaogou Formation and the salinity of the P2l1 is higher than that of the P2l2. The biomarker parameters of nC21−/nC22+, CPI, S/H, and C22T/C21T reflect that the organic matter of the source rocks have a higher abundance of bacteria and algae than higher plants, and the contents of bacteria are more than that of algae. The (7- + 8-MMAs)/Cmax and (C28 + C29 − St)/St parameters indicate that cyanobacteria accounted for a certain proportion of bacteria, and the algae are mainly green algae. The co-evolution of the sedimentary environment and the biological composition reflects the control of the sedimentary paleoenvironment on biological composition. According to the relative content of cyanobacteria, green algae, and Rhodophyta, the source rocks of the upper and lower Lucaogou Formation correspond to the low-salinity type (LS-type) and the high-salinity type (HS-type), respectively. Compared with LS-type source rocks, HS-type source rocks have greater generation potential of oil and weaker gas generation potential. This study is valuable for the accurate assessment of source rocks and holds significant practical implications for the exploration of oil and gas resources. [ABSTRACT FROM AUTHOR]

The review contains a comparative analysis of studies on the production of hydrogen and syngas based on the processes of partial oxidation of natural gas and other types of gas feedstock. The results presented in the literature show the high potential of non-catalytic autothermal processes of partial oxidation of hydrocarbons for the development of gas chemistry and energetics. The partial oxidation of hydrocarbons makes it possible to overcome such serious shortcomings of traditional syngas production technologies as technological complexity and high energy and capital intensity. The features of non-catalytic partial oxidation of hydrocarbon gases, the obtained experimental results and the results of kinetic modeling of various options for the implementation of the process, which confirm the adequacy of the kinetic mechanisms used for the analysis, are considered in detail. Examples of industrial implementation of processes based on partial oxidation and proposed alternative options for its organization are considered. Designs of reactors used to ensure stable conversion of rich mixtures of hydrocarbons with an oxidizer are presented. The possibility of obtaining other chemical products by partial oxidation of hydrocarbons is discussed. [ABSTRACT FROM AUTHOR]

Previous studies have shown that shale oil mobility depends on the relative content of free oil and adsorbed oil. However, the research on how to establish a shale oil mobility evaluation is relatively insufficient. This study aims to use pyrolysis data before and after extraction to accurately identify the content of free oil and adsorbed oil, analyze the influencing factors of shale oil mobility, characterize the hydrocarbon generation and expulsion process, and evaluate shale oil mobility. We utilized an integrated mineralogical and geochemical dataset from the PS18-1 well in the Liutun Sag, Dongpu Depression, Bohai Bay Basin. The results show that the adsorption capacity of type I organic matter (OM) on shale oil is greater than that of type II OM, the OM abundance is of great significance to shale oil mobility, and that quartz and feldspar can promote shale oil mobility. The Tmax corresponding to the threshold of hydrocarbon expulsion is 438~440 °C, and the oil saturation index (OSI) is about 158 mg/g TOC. There are four small intervals: a (3257 m~3260 m), b (3262 m~3267 m), c (3273 m~3278 m), and d (3281 m~3282 m) meeting the conditions of hydrocarbon expulsion. Large-scale hydrocarbon expulsion occurred in interval a, a small amount of hydrocarbon expulsion in interval b, a large amount of hydrocarbon expulsion in interval c, and almost no hydrocarbon expulsion in interval d. Based on the crossplot of S1 and TOC, combined with other parameters such as OSI, hydrocarbon generation potential (HGP), and free and adsorbed oil, we established an evaluation chart of shale oil mobility and divided it into five categories: A, B, C, D, and E. While categories A and C have good mobility and great resource potential, categories B and D have relatively poor mobility and medium resource potential, and category E has little mobility and is an invalid resource. [ABSTRACT FROM AUTHOR]

In this paper, we developed an effective method for purifying oil sludge using a sorbing electrochemical matrix and assessed the prospects of this method in comparison with conventional hydrocracking. We synthesized Ni-W supported hydrocracking catalysts with different morphology and studied their activity under various conditions, we compared the obtained catalysts with commercial catalyst SGK-5. We demonstrated that the introduction of a secondary mesoporous structure in the catalyst leads to an increase in the yield of light fractions to 52 wt.%. The possibility is demonstrated to obtain hydrocarbons from reservoir oil sludge, dispersed into an aqueous solution of detergent, by the method of low-temperature hydrogenation in sorbing electrochemical matrices. The obtained product was characterized by low viscosity, low content of transition metals (<320 ppm), and sulphur (<260 ppm). [ABSTRACT FROM AUTHOR]

One potential opportunity for the decarbonisation of heat supply in the UK is the repurposing of onshore hydrocarbon wells for the production and/or storage of geothermal heat. This paper reports an investigation into the most favourable candidate sites for such repurposing, taking into consideration the available thermal energy outputs and technological options for heat use. A GIS mapping model was generated, combining public domain data on onshore wells and production data from onshore fields, provided by the UK Oil and Gas Authority, with available subsurface temperature data. This model has thus integrated information on location, depth, operational status, and bottom-hole temperature for onshore hydrocarbon wells with production rates from onshore fields in the UK. Of the 2242 onshore hydrocarbon wells thus reported, 560 have the potential to be repurposed, 292 of which are currently operating. Using aggregated water production data for all operating wells in each field, the fields with the greatest potential for geothermal repurposing are ranked. Two of these, the Wytch Farm and Wareham fields, are selected for more detailed analysis. Wytch Farm, the largest onshore oilfield in western Europe, produces water at ~65 °C that might yield a feasible thermal power output of ~90 MW. If an end use could be found where it might substitute for burning of natural gas, the value of this output would be ~£90,000 per day or ~£30 million per year. However, this field is located in a protected landscape where local development would be restricted by planning regulations. The Wareham field is not in a protected landscape, but the low temperature, ~44 °C, and low flow rate limit the scope of potential end uses. Nonetheless, these and the other highly ranked fields have potential heat outputs that are significant compared with other geothermal heat projects, thus offering the possibility of making useful contributions to the decarbonisation of UK energy use. [ABSTRACT FROM AUTHOR]

This paper presents the results of a study on the influence of pressure and temperature of the gas–water medium on the process of hydrocarbon gas hydrate formation occurring at the phase interface. Herein, a mathematical model is proposed to determine the optimum ratios of pressure, gas temperatures, water, and gas bubble sizes in the bubbling, gas ejection, or mixing processes. As a result of our work, we determined that gas hydrate in these processes is formed at the gas–water interface, that is, on the boundary surface of gas bubbles. Moreover, there is a gas temperature range where the hydrate formation rate reaches its maximum. These study findings can be used to optimize various technological processes associated with the production of gas hydrates in the industry. [ABSTRACT FROM AUTHOR]

This paper investigates the nucleate boiling process of dimethyl ether and selected hydrocarbons. The main goal of this study is to measure the heat transfer coefficients of RE170, R600a, and R601, and to compare them with R134a. The experiments were carried out for heat fluxes up to 70 kW/m2. Experimental results have shown a typical trend that the heat transfer coefficient of flammable refrigerants increases as the heat flux increases. Among the tested fluids, the highest values of heat transfer coefficient were obtained for RE170. Available correlations describing this coefficient showed a deviation of up to 93%, as compared to the data obtained. The new correlation was developed by regression analysis taking into account dimensionless variables affecting the boiling process. [ABSTRACT FROM AUTHOR]

To understand hydrocarbon migration in terms of the mechanisms, accumulations and exploration targets, it is essential to correctly identify and characterize the carrier systems that control fluid-migration history and oil/gas reservoir formation. The Yinggehai Basin in China is an important area for natural gas exploration and production. However, due to the argillaceous sand sedimentary environment and the absence of faults from the Neogene thermal subsidence period, traditional migration pathways are absent in the Yinggehai Basin, posing significant challenges to target evaluation in this area. Exploration shows that most of the existing gas reservoirs are associated with vertical migration. In this work, coherence cube and curvature seismic techniques are used in the central diapir zone of the Yinggehai Basin to identify diapir-associated fractures and regional stress. Together with geological analysis, two categories of carrier system are discussed in detail to explain the complex migration and accumulation patterns that have puzzled the area. Diapirs have five evolutionary phases, i.e., pressurization, piercing, equilibrium, release and collapse, which have different fracture development patterns, leading to different mechanisms of hydrocarbon migration and accumulation. The carbon isotopes of gaseous hydrocarbons in DF shallow layers and mid-deep layers have an inverted order distribution, indicating mixed accumulation with different maturity, whereas in the mid-deep layers of the diapir-affected areas, there is a single accumulation with low maturity. Early diapiric activity allowed the natural gas produced from deep source rocks to migrate upward along the diapiric carrier system and accumulate in suitable traps to form gas reservoirs. For regional-stress related fractures, the gradual loss of overpressure and fluids from deep to shallow in high-pressure fractures results in the gas accumulation time of deep traps in the regional stress-related carrier system being relatively late and the gas accumulation time of shallow traps being relatively early. [ABSTRACT FROM AUTHOR]

Gas injection has already proven to be an efficient shale oil recovery method successfully tested all around the world. However, gas-enhanced oil recovery methods have never been implemented or tested for the greatest Siberian shale oil formation yet. This article proposes numerical simulation of a hydrocarbon gas injection process into a horizontal well with multiple hydraulic fractures perforating Bazhenov shale oil formation in Western Siberia characterized by ultra-low permeability. A complex field-scale numerical study of gas injection for such a formation has never been performed before and is presented for the first time in our work. The hydrodynamic compositional simulation was performed utilizing a commercial simulator. A sensitivity study for different operating parameters including cycle times, bottom-hole pressures for the production and injection period, and injected gas composition was performed after the model was history matched with the available production data. Some uncertain reservoir properties such as relative permeability curves were also sensitized upon. Two different ways of accounting for multiple hydraulic fractures in the simulation model are presented and the simulation results from both models are compared and discussed. Eventually, huff-n-puff injection of a hydrocarbon gas resulted in a 34–117% increase in oil recovery depending on the fracture model. [ABSTRACT FROM AUTHOR]

Organic matter (OM) type critically controls the hydrocarbon generation potential and organic pore development in black shales. However, maceral variation in lacustrine shales and its control on hydrocarbon generation potential and organic pore development are not yet well understood. In this study, 15 Chang 7 Member shale samples of the Yanchang Formation, Ordos Basin, were investigated with organic petrography, Rock-Eval pyrolysis, and a scanning electron microscope to study the maceral composition, hydrocarbon generation potential, and organic pores in this black shale succession. The results show that the studied shales are in the oil window (Ro~0.70%). OM belongs to Type I and Type III kerogen, as demonstrated by Rock-Eval pyrolysis. Macerals in the Chang 7 Member shales are composed of amorphous OM, alginite, sporinite, liptodetrinite, vitrinite, inertinite, and solid bitumen. Amorphous OM and alginite are major hydrocarbon-generating macerals, and their content determines the hydrocarbon potential of shales. Secondary organic pores were not observed in the studied Chang 7 Member shales due to either a low thermal maturity or a dominance of terrigenous OM. Maceral variation can affect the reliability of using Rock-Eval Tmax as a thermal maturity indicator. This study provides important insights into maceral control on hydrocarbon generation and organic pore development in black shales, calling for a critical evaluation of OM in black shale successions with organic petrography. [ABSTRACT FROM AUTHOR]

Hydrocarbon fluid migration through faulted cap rocks was determined by comparing the maximum connected thickness of cap rocks required for hydrocarbon fluid migration and the actual values, since cap rocks are important in the study of hydrocarbon fluid distribution in petroliferous basins based on its migration mechanism(s). The maximum connected thickness required was identified by comparing the cap rocks, fault displacement, and oil/gas distribution. The hydrocarbon fluid at the Putaohua reservoir migrated to the overlying Saertu and Heidimiao reservoirs in the Bayan Chagan Area, northern Songliao Basin. This was predicted to demonstrate the validity of the method. The results show that the adjusted Putaohua oil reservoir was distributed near the Talahai fault and Bayanchagan fault, rather than the Gulong sag in the southwest of the study area, where oil migrated vertically through the Sapu cap rocks to the overlying Saertu reservoir. Thick mudstone cap rocks in the second member of the Nenjiang Formation made it difficult for hydrocarbon fluid to migrate to the Heidimiao reservoir. This agrees well with hydrocarbon fluid distribution at the Putaohua, Saertu, and Heidimiao reservoirs in the Bayan Chagan Area, indicating that this method is feasible for predicting hydrocarbon fluid migration through faulted cap rocks. [ABSTRACT FROM AUTHOR]

Shale oil resources are important supplements for the gradually decreasing oil production from conventional reservoirs. Although the exploitation and development of shale oil have achieved considerable progress in the last decade, the commercial extraction of hydrocarbons from shales is still difficult, especially in the lacustrine sedimentary basins of China. One of the key points controlling the successful extraction of hydrocarbons from shale systems is the understanding of the occurrence mechanism of shale oil. This study comprehensively summarizes the theories and techniques to characterize oil occurrence state, occurrence space, oil content, and oil movability in shale systems. Sophisticated instruments, such as high-resolution scanning electron microscopy and high-energy ray imaging, were utilized to qualitatively analyze the pore networks of shales. Advanced physical experiments and numerical simulation techniques, including step-by-step rock pyrolysis, solvent extraction, and NMR, were introduced to characterize shale oil adsorption and movability. By the comparative analysis of the occurrence space, it is found that the image observation technique especially focuses on concentrated pores, such as organic matter-hosted pores. The fluid injection technology yields particular pore size information, which should be calibrated using other information. The 3D digital core, demonstrating the spatial distribution of minerals and pores, is an effective input for shale oil flow simulation. Geological controls analysis about oil retention in organic-rich shales has found that the inorganic matter pores and fractures are probably the "sweet spot" of shale oil, due to the low oil adsorption and high light hydrocarbons content. Many physical experiments measure the total free oil content but neglect the hydrocarbon–rock interaction and the sequential migration of hydrocarbon compounds. Thus, micro-scaled experiments measuring the hydrocarbon adhesion forces are needed to uncover the occurrence mechanism of shale oil in the future. [ABSTRACT FROM AUTHOR]

The effect of the fuel injection ratio on the combustion and emission characteristics of stratified lean mixture combustion was investigated for a spray-guided liquefied petroleum gas (LPG) direct injection engine. Inter-injection spark-ignition combustion-a specially designed combustion strategy for LPG fuel derived from a two-staged injection-was employed to maximize the improvement in thermal efficiency when combustion stability is secured. When changing the fuel injection ratio, the optimum spark advance and fuel injection timings were experimentally determined to maximize the thermal efficiency based on sweeping timings. The optimum fuel injection ratio with the highest thermal efficiency (42.76%) and stable operation was 60%/40%, with the optimization of the spark advance and fuel injection timing, because of the locally rich mixture region in the recirculation zone. NOx emissions were at their highest level with a fuel injection ratio of 60%/40% because of the high combustion temperature, and the levels of total hydrocarbon and CO emissions with 50%/50% and 60%/40% fuel injection ratios were similar, whereas emissions at 70%/30% were significantly higher because of fuel wetting and the formation of over-lean mixture. [ABSTRACT FROM AUTHOR]

Optical Gas Imaging (OGI) cameras represent an interesting tool for identifying leaking components in hydrocarbon processing and transport systems. They make it possible to see exactly where a leak originates, thereby enabling efficient leak detection and repair (LDAR) programs. The present paper reports on an OGI test campaign initiated by the Norwegian Environmental Agency (NEA), and how this campaign stimulated cross-disciplinary cooperation at an LNG plant for better control of both fugitive hydrocarbon emissions and safety-related leaks. A surprising potentially severe leak detected in the NEA campaign triggered the introduction of in-house OGI cameras at plants and refineries, and an inter-disciplinary cooperation between specialists in the environment, technical safety and operations. Some benefits of in-house OGI cameras, as well as some concerns regarding their use are presented and discussed. The general experience is that an Ex safe, i.e., rated for safe use in a combustible hydrocarbon gas atmosphere, OGI camera, represents a very valuable tool for detecting fugitive emissions as the start point for LDAR programs. An OGI camera did, however, also turn out to be a valuable tool for fire and explosion risk management, and has led to reduced downtime after leak incidents. The concerns relate to leaks seen through the OGI camera that may look overwhelming, even with concentrations well below the ignitable limits of the released gas. Based on the LNG plant experiences, it is generally recommended that specialists in the environment, technical safety, operations and teaching fields cooperate regarding the introduction and use of OGI cameras. Suggestions for training courses are also discussed. [ABSTRACT FROM AUTHOR]

This paper summarizes a study based on a modified, light, single-cylinder diesel engine and the effects of the physicochemical properties for n-butanol-diesel blended fuel on the combustion process and hydrocarbon (HC) emissions in the intake at a medium speed and moderate load in, an oxygen-rich environment (Coxy = 20.9–16%), an oxygen-medium environment (Coxy = 16–12%), and an oxygen-poor environment (Coxy = 12–9%). The results show that the ignition delay period is the main factor affecting the combustion process and it has a decisive influence on HC emissions. In an oxygen-medium environment, combustion duration affected by the cetane number is the main reason for the difference in HC emissions between neat diesel fuel (B00) and diesel/n-butanol blended fuel (B20), and its influence increases as the intake oxygen concentration decreases. In an oxygen-poor environment, in-cylinder combustion temperature affected by the latent heat of vaporization is the main reason for the difference in HC emissions between B00 and B20 fuels, and its influence increases as the intake oxygen concentration decreases. By comparing B20 fuel with diesel/n-butanol/2-ethylhexyl nitrate blended fuel (B20 + EHN), the difference in the ignition delay period caused by the difference in the cetane number is the main reason for the difference in HC emissions between B20 and B20 + EHN fuels in oxygen-poor environment, and the effect of this influencing factor gradually increases as the intake oxygen concentration decreases. [ABSTRACT FROM AUTHOR]

This paper presents insights on flow in porous media from a model tool based on complex analysis methods (CAM) that is grid-less and therefore can visualize fluid flow through pores at high resolution. Elementary pore network models were constructed to visualize flow and the corresponding dynamic bottomhole pressure (BHP) profiles in a well at reservoir outflow points. The pore networks provide the flow paths in shale for transferring hydrocarbons to the wellbore. For the base case model, we constructed a single flow path made up of an array of pores and throats of variable diameter. A passive ganglion (tracer) of an incompressible fluid was introduced to demonstrate the deformation of such ganglions when moving through the pores. The simplified micro-flow channel model was then expanded by stacking flow elements vertically and horizontally to create complex flow paths representing a small section of a porous reservoir. With these model elements in place, the flow transition from the porous reservoir fluid to the wellbore was modeled for typical stages in a well life. The dynamic component of the bottomhole pressure (BHP) was modeled not only during production but also during the drilling of a formation (with either balanced, underbalanced or overbalanced wellbore pressure). In a final set of simulations, the movement of an active ganglion (with surface tension) through the pore space was simulated by introducing a dipole element (which resisted deformation during the movement through the pores). Such movement is of special interest in shale, because of the possible delay in the onset of bubble point pressure due to capillarity. Capillary forces may delay the reservoir to reach the bubble point pressure, which postpones the pressure-drop trigger that would lead to an increase of the gas–oil ratio. The calculation of the estimated ultimate recovery (EUR) with an erroneous assumption of an early increase in the gas–oil ratio will result in a lower volume than when the bubble point delay is considered. [ABSTRACT FROM AUTHOR]

The geochemistry of produced fluids has been investigated in the Triassic Montney Formation in the Western Canadian Sedimentary Basin (WCSB). Understanding the geochemistry of produced fluids is a valuable tool in the exploration and development of a complex petroleum system such as the Montney Formation. The petroleum system changes from in situ unconventional reservoirs in the west to more conventional reservoirs that contain migrated hydrocarbons to the east. The workflow of basin modeling and mapping of isomer ratio calculations for butane and pentane as well as the mapping of excess methane percentage was used to highlight areas of gas compositional changes in the Montney Formation play area. This workflow shows the migration of hydrocarbons from deeper, more mature areas to less mature areas in the east through discrete pathways. Methane has migrated along structural elements such as the Fort St. John Graben as well as areas that have seen changes in higher permeability lithologies (i.e., well 14-23-74-8W6M). Excess methane percentage calculations highlight changes due to fluid mixing from hydrocarbon migration. The regional maturation polynomial regression line was used to determine the gas dryness percentage for each well on the basis of its maturation level determined by the butane isomer ratio. The deviation from the calculated gas dryness according to the regression was determined as an excess methane percentage. The British Columbia (BC) Montney play appears to have hydrocarbon compositions that reflect an in situ generation, while the Montney play in Alberta (AB) has a higher proportion of its hydrocarbon volumes from migrated hydrocarbons. The workflow provides a better understanding of the hydrocarbon system to optimize operations and increase production efficiency. Understanding the distribution of gas compositions within a play area will provide key information on the liquid and gas phases present and an understanding of how gas composition may change over the well life, as well as helping to maximize liquid recovery during well operations. [ABSTRACT FROM AUTHOR]

From the late 1900s onward, hydrocarbon exploitation has led to severe environmental footprints in the Khuzestan province, Iran. However, no comprehensive study has been conducted to evaluate such issues. In this research, an inclusive analysis was performed to investigate these environmental impacts. To do this, first, two datasets related to a 15-year period (2006–2021) were collated: the satellite data from the Sentinel-1 mission and the seismic data recorded by the National Iranian Geophysics Institute as well as the catalog of the global Centroid Moment Tensor project (CMT). These datasets were processed using generic mapping tools (GMT), differential synthetic aperture radar (D-InSAR) techniques, and multiple processing algorithms using a specific toolbox for oil spill application in the sentinel application platform (SNAP) programming, respectively. The results revealed three critical footprints, including regional earthquakes, land subsidence, and oil spill issues in the area. The most frequent earthquakes originated from depths less than 15 km, indicating the disturbance of the crustal tectonics by the regional hydrocarbons. Furthermore, an annual rate of land subsidence equal to 10–15 cm was observed in the coastal areas of the Khuzestan province. Moreover, two regions located in the north and west of the Persian Gulf were detected as the permanently oil-spilled areas. The applied methodology and results are quite applicable to restrict the harmful consequences of hydrocarbon production in the study area. This research will benefit not only government officials and policymakers, but also those looking to understand the environmental challenges related to oil and gas production, especially in terms of sustainable goals for the management of natural resources. [ABSTRACT FROM AUTHOR]

The Ri-Qing-Wei Basin is a newly discovered Late Mesozoic rift basin on the eastern Shandong coast in recent years. Thick, continuous deposited source rocks are found in the Lingshan Island scientific drilling project. Therefore, it is necessary to evaluate the distribution and hydrocarbon generation potential of source rocks in this area. Organic geochemical experiments were carried out on samples from the core of LK-1 and outcrops in the Lingshan Island, the Laoshan area, and the Jimo Zhougezhuang area to evaluate the maturity, abundance, and type of organic matter in source rocks. The results show that the cumulative thickness of the source rocks in the study area is more than 500 m, and the TOC content is generally greater than 1.0%. The organic matter type is good (mainly type II1 and type II2 kerogen) and the Ro value is more than 2.0. The thermal evolution degree of the organic matter is high with natural gas predominantly generated. We carried out Rock-Eval, PY-GC and gold tube experiments on low-maturity samples of Laikong 2 and established a chemical kinetic model to quantitatively evaluate the study area in combination with sedimentary burial history and thermal history data. The results show that the total resources of the five sags in the study area are about 476 billion cubic meters, and the average resource intensity is about 82.2 million cubic meters/km2. Among them, the resource intensities of the Lingshan Island Sag and Laoshan Sag are 112.6 million cubic meters/km2 and 98.8 million cubic meters/km2, respectively. Studied sites are "small and fertile" and may be used as favorable exploration prospect areas. [ABSTRACT FROM AUTHOR]

The Shahejie Formation (Fm) in the Bohai Bay Basin is well-known for its substantial conventional resource potential and long-term history of exploration. Shale oil has been confirmed as a sustainable resource following breakthroughs in shale exploration in the first and third members of the Paleogene Shahejie Fm (Mbr1 and Mbr3) in Qikou Sag, particularly Mbr3, which has a more desirable output. However, the limited distribution of exploration wells for shale oil around the southwest of Qikou Sag calls for a comprehensive evaluation of shale oil (or gas) potential in all of Qikou Sag. Here, we clarify the shale oil (or gas) resource potential and areas favorable for exploration in Mbr3 by using a hydrocarbon generation potential model (HGPM) based on the material balance method and the principle of hydrocarbon (HC) generation dynamics. Apart from the quantified characteristics of the oil generation process of Mbr3 source rocks, the source rocks of both Mbr1 and Mbr3 were compared to interpret the discrepancies in HC generation. The results show that Mbr3 source rocks have high-quality geological and geochemical features, a thickness of 1200 m, and adequate organic matter (1.66% TOC on average, dominated by kerogen II&III, and in the mature stage). The threshold of expulsion is Ro = 0.78%; correspondingly, HC generation potential (Qg), HC expulsion potential (Qe), and retention potential (Qr) are, at maximum, 605.89, 169.65, and 436.24 mg HC/g TOC. The intensity of HC generation (Ig), expulsion (Ie), retention (Ir), and effective retention (Ire) is focused on the main depression and the Qibei Sub-sag and can reach as high as 250 × 104, 65 × 104, 170 × 104, and 110 × 104 t/km2, respectively. The resource potential for the retention of shale was calculated to be 13.3 × 108 t (movable shale oil and gas 8.0 × 108 t), and conventional and tight oil or gas resources were calculated to be 4.7 × 108 t (equivalent oil resources). Favorable exploration targets are spread around the main depression and the Qibei Sub-sag. There are disparities in the thermal process and thermal generation, and expulsion features between Mbr1 and Mbr3 source rocks are derived from kerogen-type and non-isolated deposit environments. Thus, a quantitative, advanced evaluation and a comparison offer more precise exploration predictions of shale in this Fm and further boost the low-risk exploration process. [ABSTRACT FROM AUTHOR]

The Mesozoic Chang 8 Section in the Zhenjing area is a typical low permeability-tight sand reservoir and is regarded as the most important set of paybeds in the study area. Guided by the principles of basic geological theory, the diagenetic evolution process and hydrocarbon accumulation periods of the Chang 8 reservoir in the study area were determined through various techniques. More specifically, core observation, scanning electron microscopy (SEM), X-ray diffraction (XRD), and vitrinite reflectance experiments were performed in combination with systematic studies on rock pyrolysis and the thermal evolutionary history of basins, the illite-dating method, and so on. The Chang 8 reservoir is dominated by feldspar lithic and lithic feldspar sandstones. Quartz, feldspar, and lithic fragments are the major clastic constituents. In clay minerals, the chlorite content is the highest, followed by illite/smectite formation and kaolinite, while the illite content is the lowest. The major diagenesis effect of the Chang 8 reservoir includes compaction, cementation, dissolution, metasomatism, and rupturing. The assumed diagenetic sequence is the following: mechanical composition → early sedimentation of chlorite clay mineral membrane → early cementation of sparry calcite → authigenic kaolinite precipitation → secondary production and amplification of quartz → dissolution of carbonate cement → dissolution of feldspar → late cementation of minerals such as ferrocalcite. Now, the study area is in Stage A in the middle diagenetic period. Through the inclusion of temperature measurements, in conjunction with illite dating and thermal evolutionary history analysis technology in basins, the Chang 8 reservoir of this study was determined as the phase-I continuous accumulation process and the reservoir formation epoch was 105~125 Ma, which was assigned to the Middle Early Cretaceous Epoch. [ABSTRACT FROM AUTHOR]

A prediction method of hydrocarbon distribution associated with fault-shale caprock configuration leakages is established through superposing hydrocarbon distribution at deep basin fault-shale caprock configuration leakages, and conducting faults to understand distribution of shallow reservoirs of "lower generation, upper accumulation" in petroliferous basins based on fault-shale caprock configuration leakage mechanism. Prediction of hydrocarbon distribution at the Ed-3 Member in the south of the northern Dagang area of Bohai Bay Basin was used to demonstrate the application of the proposed method. Results show that predicted oil and gas at the Ed-3 Member are mainly distributed in the middle of the north and in the middle of the south edge, where fault-shale caprock configuration leakages in the middle of the Sha-1 Member contributed positively to oil and gas migration from the hydrocarbon reservoir at deep basin to the shallow reservoirs. The prediction matches well with discovered oil and gas in this area, proving the validity of this method. [ABSTRACT FROM AUTHOR]

The use of CO2-based hydrocarbons plays a crucial role in reducing the climate footprint for several industry sectors, such as the chemical industry. Recent studies showed that regions which are favorable for the production of CO2-based hydrocarbons from an energy perspective often do not provide concentrated point sources for CO2, which leads to an increased environmental impact due to the higher energy demand of direct air capture processes. Thus, producing H2 in regions with high renewable power potential and transporting it to industrialized regions with concentrated CO2 point sources could provide favorable options for the whole process chain. The aim of this study is to analyze and compare pathways to produce CO2-based methanol in Germany using a local CO2 point source in combination with the import of H2 per pipeline or per ship as well as H2 produced in Germany. The environmental and economic performance of the pathways are assessed using life cycle assessment and cost analysis. As environmental indicators, the climate, material, water, and land footprints were calculated. The pathway that uses H2 produced with electricity from offshore wind parks in Germany shows the least environmental impacts, whereas the import via pipeline shows the best results among the importing pathways. The production costs are the lowest for import via pipeline now and in the near future. Import via ship is only cost-efficient in the status quo if waste heat sources are available, but it could be more competitive in the future if more energy and cost-efficient options for regional H2 distribution are available. It is shown that the climate mitigation effect is more cost-effective if the H2 is produced domestically or imported via pipeline. Compared to the import of CO2-based methanol, the analyzed H2 import pathways show a comparable (pipeline) or worse environmental and economic performance (ship). [ABSTRACT FROM AUTHOR]