Charge History Research Articles

Light Oil Reservoir Source and Filling Stage in the Chepaizi Uplift, Junggar Basin Evidence from Fluid Inclusions and Organic Geochemistry

The light oil wells within the Neogene Shawan Formation have been extensively drilled in the Chepaizi Uplift, reflecting an increase that provides new targets for unconventional resources in the Junggar Basin of northwestern China. However, the original sources of light oil remain controversial, as several source rocks could potentially generate the oil. For this study, we collected light oils and sandstone cores for biomarker detection using gas chromatography–mass spectrometry (GC-MS). Additionally, fluid inclusions were observed and described, and the homogenization temperatures of saltwater inclusions were measured to confirm the oil charging history in conjunction with well burial and thermal history analysis. Based on these geochemical characteristics and carbon isotopic analysis, the results indicate that light oil in the Chepaizi Uplift zone primarily originates from Jurassic hydrocarbon source rocks in the Sikeshu depression, with some contribution from Cretaceous hydrocarbon source rocks. Jurassic hydrocarbon source rocks reached a peak of hydrocarbon generation in the middle to late Neogene. The resulting crude oil predominantly migrated along unconformities or faults to accumulate at the bottom of the Cretaceous or Tertiary Shawan Formation, forming anticlinal or lithologic oil reservoirs. Some oil reservoirs contain mixtures of Cretaceous immature crude oil. During the Neogene light oil accumulation process, the burial rate of reservoirs was high, and the efficiency of charging and hydrocarbon supply was relatively high as well. Minimal loss occurred during the migration of light oil, which significantly contributed to its rapid accumulation.

Diagenesis and Hydrocarbon Charging History of the Late Triassic Yanchang Formation, Ordos Basin, North China

The Yanchang Formation of the Triassic in the Ordos Basin comprises various stratigraphic intervals. The Chang 8 reservoir represents a significant oil-producing section of the Yanchang Formation, and its hydrocarbon accumulation mechanism is complex. In this study, we analyzed the diagenetic evolution and reservoir-forming stages of the Chang 8 member of the Yanchang Formation in the Late Triassic in the Fuxian area, the southern Ordos Basin, via thin-section casting, scanning electron microscopy (SEM), X-ray diffraction, and fluid inclusion petrology and homogenization temperature analyses. The relationship between the petrogenesis and hydrocarbon charging history was analyzed, which provided guidance for identifying and predicting the hydrocarbon reservoir distribution. The results show that the main diagenesis types of the Chang 8 reservoir are compaction, cementation, dissolution, and metasomatism. The comprehensive analysis of the reservoir mineral types, diagenesis, diagenetic sequence, and thermal evolution degree of organic matter shows that the Chang 8 reservoir of the Yanchang Formation is in the A stage of the middle diagenesis stage. Under the overpressure of hydrocarbon generation, oil and gas migrated into the Chang 8 reservoir along fractures and connected pores. The earlier-stage hydrocarbon charging occurred after compaction and later than the early clay film formation and early calcite precipitation, and it also occurred earlier than or simultaneously with the quartz overgrowth. The later hydrocarbon charging occurred after the significant quartz overgrowth and late calcite pore filling. Depending on the homogenization temperature and salinity, the fluid inclusions can be divided into two types: low-temperature, low-salt (90–105 °C, 1.4%–11.2%) fluid inclusions and high-temperature, high-salt (115–120 °C, 2.2%–12.5%) fluid inclusions. According to the analysis of the evolution of the burial history, hydrocarbon charging in the Chang 8 reservoir of the Yanchang Formation in the Fuxian area occurred in two consecutive periods: 133~126 Ma and 122~119 Ma, demonstrating one-scene, two-stage reservoir formation, characterized by simultaneous reservoir densification and hydrocarbon charging. In this research, we precisely ascertained the regional diagenetic characteristics and patterns and periods of hydrocarbon charging, thereby furnishing crucial evidence that deepens the comprehension of sedimentary basin evolution.

Effects of Main Aging Mechanism and State of Charge on the Safety of 21700 Li-Ion Battery Cells with Ni-Rich NMC Cathode

It is known that both the material used in Li-ion battery cells, as well as their aging history and state of charge (SOC), strongly impact the safety of such cells. This study investigates the safety characteristics of new or aged 21700 cells containing silicon-graphite blend anodes together with Ni-rich NMC cathodes by accelerating rate calorimetry (ARC) at different SOC. Cells underwent cyclic aging at 0 °C, room temperature, or 50 °C to induce different aging mechanisms including Li plating and solid electrolyte interphase growth. The quasi-adiabatic heat-wait-seek ARC tests show lower temperatures for self-heating (SH), CID triggering, venting, and thermal runaway (TR) with increasing SOC, indicating reduced safety levels. Furthermore, the mass loss and TR intensity increase as the SOC of the cell increases. Aged cells show a similar SOC dependence as new cells in view of venting and TR, although both temperatures are reduced. The onset of SH at around 35 °C, independent of SOC, reveals a significant safety issue in cells with Li plating. Additional cell voltage monitoring and on-line mass spectrometry provide further insights into the decomposition processes. Our findings provide essential knowledge to improve the safety and design of Li-ion battery cells by identifying unsafe states.

The Life and Death of Hydrocarbon Traps in East Greenland: The Charge and Degradation Histories of Laplace Bjerg and the Mols Bjerge

ABSTRACTThe exhumed hydrocarbon traps of East Greenland provide a superb opportunity to study the evolution of fluid flow in the petroleum systems of the North Atlantic. Following basin inversion during the Cenozoic these structures were exhumed and deeply incised which has allowed them to be observed and mapped in great detail. This study examines the diagenetic history of the Mols Bjerge and Laplace Bjerg exhumed hydrocarbon traps, from the initial charge of Triassic and Jurassic reservoirs, to their eventual uplift and destruction. Detailed petrographic analysis was undertaken on 67 samples collected at representative intervals throughout the structures. Variations in the distribution of diagenetic phases and remnant porosity were investigated. Twenty three samples were also subjected to helium porosity measurement. Bitumen, up to 18%, was recognised in 34 samples, 6 of which were analysed for their form and reflectance. Fluid inclusion data, collected from the nearby Bjørnedal region, helps to constrain the thermal history of the region. Helium porosity and permeability measurements are low, largely below 10% and 2 mD respectively. However, the abundance of bitumen highlights the presence of significantly higher porosity and permeability during hydrocarbon charge. A synthesis of fluid inclusion data and bitumen reflectance, alongside a detailed examination of the paragenetic sequence, demonstrate that hydrocarbon charge occurred in the Eocene, during maximum burial, at which time only a minor reduction in original intergranular porosities had taken place. The destruction of the pore systems occurred due to the degradation of hydrocarbons to bitumen, resulting from heat flow during intrusive events, and subsequent carbonate and limonite cementation during uplift. The original source of the hydrocarbons is unclear. This work highlights that where unaffected by intrusives and uplift, the largely untested Triassic play may still contain viable reservoir intervals at depth on the Norwegian Continental Shelf.

Hydrocarbon charge history of deeply buried clastic reservoirs in the Bozi area of the Kuqa Depression, western China: implications for deep and ultra-deep petroleum exploration

Significant progress has recently been made in deep and ultra-deep oil and gas exploration globally, demonstrating enormous exploration potential of the deep and ultra-deep strata. However, the accumulation and preservation pattern of deep and ultra-deep oil and gas remains poorly understood, greatly impeding further petroleum exploration and development in the deep and ultra-deep strata. By taking the Bozi deep and ultra-deep condensate gas reservoirs in the Kuqa Depression, western China as an example, we attempt to reconstruct the hydrocarbon charge history in such deep reservoirs via an integrated investigation involving quantitative grain fluorescence, fluid inclusion petrography and microthermometry, micro-fluorescence spectroscopy, laser Raman spectroscopy, PVTx modelling, and basin modelling. The results show that: (1) The Bozi deep and ultra-deep reservoirs contain one group of gas inclusion assemblage, and two groups of oil inclusion assemblages, with one being characterized by near yellowish-whitish and blue-whitish diphasic or triphasic oil inclusions, and the other being featured by bright blue diphasic oil inclusions; (2) The first oil charge occurred during the Early Neogene (6.5–5.5 Ma), and the second oil charge occurred during the Late Neogene (4.4–3.5 Ma), under normal hydrostatic pressure or slightly weak overpressure; and (3) The gas charge occurred during the Pleistocene (∼1.6 Ma), with a corresponding reservoir pressure coefficient of approximately 1.7, transforming the reservoir fluid phase state from black oil or volatile oil to condensate gas. Our findings highlight that aside from the present burial depth, a favorable burial history model is crucial for the preservation of liquid hydrocarbons in deep and ultra-deep reservoirs. The occurrence of liquid hydrocarbons in the Bozi deep and ultra-deep condensate gas reservoirs with depths over 7,000 m is benefited from a prolonged period (>100 Ma) of shallow burial and a late-stage (since 10 Ma) rapid subsidence.

Hydrocarbon accumulation and reconstruction in the Ediacaran Dengying carbonate reservoirs of the southeastern and central Sichuan Basin, SW China

The carbonate reservoirs of the Ediacaran Dengying Formation (Z2dn) in the southeastern Sichuan Basin (SESB) and central Sichuan Basin (CSB) experienced different tectonic movements during the Caledonian, Yanshanian, and Himalayan orogenies, resulting in distinct hydrocarbon accumulation processes in these two regions. Based on a detailed analysis of diagenetic sequences, pore-fluid pressure evolution, hydrocarbon charge history, and regional tectonic structural analysis, the hydrocarbon accumulation processes in the Dingshan and Ziyang areas can be divided into three stages, namely Triassic to Jurassic, Jurassic to Cretaceous, and from Late Cretaceous to the present. The first stage was characterized by the formation of paleo-oil pools, marked by an episode of oil charge in the Z2dn reservoirs, as evidenced by solid bitumen and bitumen-bearing inclusions. During the second stage, pore fluid pressure increased from normal to overpressure due to oil cracking in the favorable preservation conditions, leading to the formation of paleo-gas pools in the SESB and CSB. The timing of gas charge in the Dingshan and Ziyang area was at 173 Ma and 165 Ma, respectively, according to the trapping temperature of gas inclusions. The third stage was marked by a pressure drop from overpressure to normal pressure, possibly due to gas dissipation during the Yanshanian-Himalayan uplift. The destruction of paleo-gas pools in the Dingshan area, accompanied by gas leakage through faults and fractures, was caused by intense tectonic movement in the SESB. In contrast, the low gas productivity in the Ziyang area of the CSB was attributed to the migration of natural gas into the Weiyuan area. The fluid evolution of carbonate reservoirs and various tectonic characteristics reveal similar hydrocarbon accumulation but different reconstruction processes in the SESB and CSB, providing greater insight into the mechanism of hydrocarbon enrichment in the Sichuan Basin and other multi-cyclonic composite basins.

Hydrocarbon migration and accumulation in buried hills based on quantitative fluorescence techniques, fluid inclusion, and 1D basin modeling: Shulu sag, Bohai Bay basin, NE China

Interpreting the hydrocarbon generation, migration, and accumulation process is significant for understanding hydrocarbon evolution and finding exploration targets. The buried hills of Shulu Sag exhibit great potential for hydrocarbon exploration. However, the variations observed in different oil reservoirs highlight the complexity of hydrocarbon migration and accumulation in this region. In this study, 1D basin modeling, fluid inclusion analysis, and quantitative fluorescence techniques were used to investigate the thermal maturation history of the source rock, the timing of hydrocarbon charging, the pathway of hydrocarbon migration, and the oil-water contact. Hydrocarbons in the buried hills in the Western Slope and Paleo-uplift are derived from the source rocks at the edge and center of the sag, respectively, which have different thermal maturation histories. The source rocks in the center of the sag mainly supply hydrocarbons to the Paleo-uplift through faults, while the hydrocarbons generated from the source rocks in the edge of the sag can be rapidly transported to the Western Slope through clast-supported terrigenous carbonate rudstone. Differences in oil sources result in different hydrocarbon charging histories for the Western Slope and Paleo-uplift. The Western Slope experienced a single low-mature oil charging event at 5-0 Ma, while the Paleo-uplift encountered two hydrocarbon charging events, including low-mature oil charging at 35-25 Ma and high-mature oil charging at 5-0 Ma. As a result of secondary changes controlled by the hydrological environment, the oil reservoirs in the Western Slope have undergone varying degrees of adjustment or even destruction, resulting in variations in the oil quality of different buried hills. The results provide a detailed understanding of hydrocarbon migration and accumulation in the study area, which can be used as a reference for hydrocarbon exploration.

Fault characterization and its significance on hydrocarbon migration and accumulation of western Tazhong Uplift, Tarim Basin: Insight from seismic, geochemistry, fluid inclusion and in situ U-Pb dating

Understanding the mechanisms of deep hydrocarbon accumulation is of paramount importance in the field of petroleum geology. Studying deep hydrocarbon accumulation mechanisms contributes to the development of effective reservoir management strategies and efficient extraction techniques. In this study, fluid inclusion observation, homogenization temperatures, in situ calcite U-Pb dating, geochemical analyses and seismic data were applied to investigate the hydrocarbon charging history of the western Tazhong Uplift, and the migration pathways were further analyzed to establish the history of oil and gas accumulation in the study area. The results reveal three distinct episodes of oil and gas charging processes in the western Tazhong Uplift. The first episode, determined by in situ calcite U-Pb dating bearing primary oil inclusions, occurred during the late Caledonian to early Hercynian orogeny. This episode is characterized by yellowish fluoresce color oil inclusions. The second episode involved a complex variation of the thermal maturity of oil. Mature oil, with oil inclusions preferentially fluorescing yellow-green color, was charged into the reservoirs near the Tazhong No.1 fault. Subsequently, the high mature oil characterized by blue-fluorescing oil inclusions was charged. At the same time, the mature oil migrated vertically into the reservoir away from the Tazhong No.1 fault along the strike slip faults. The third charging process is dominant by high mature oil in the Southwest of the western Tazhong Uplift, whereas the gas intrusion occurred in the area near the Shuntuoguole Low Uplift. Furthermore, the strike slip faults and reverse faults were distinguished based on the seismic profiles and coherence diagram. The intersections of strike slip faults and Tazhong No.1 fault developing more fractures served as oil and gas charging points. The oil production revealed that the strike slip faults acted as important hydrocarbon migration pathways. This study provides valuable insights into the processes of hydrocarbon accumulation and offers further evidence for deep oil exploration in the region.

Psychopathy traits explain variance shared between features of substance use disorders and violence.

There is a substantial research literature on identifying risk and protective factors for violence perpetration. Substance use disorders have long been identified as constituting a significant predictor of violent behaviour. Psychopathy traits have also been similarly recognised, but inter-relationships between psychopathy traits, features of substance use disorders and violence have been little explored. To determine the degree to which shared variance between substance dependence symptoms and violence, as indicated by criminal charges for violent offences, among jailed men can be explained by psychopathy traits. Features of dependence on substances in three drug classes (alcohol, cannabis and cocaine) were assessed in a sample of 682 men in a county jail awaiting trial on criminal charges, many for violent offences. Statistical comparisons of zero-order and partial correlations tested whether accounting for psychopathy total and facet scores, assessed by the Psychopathy Checklist-Revised (PCL-R), affected associations between substance dependence symptoms and violent charges. Total PCL-R scores accounted for a significant proportion of the shared variance between the history of criminal charges for violence offences and lifetime substance dependence symptoms in all three drug classes. At the facet level, controlling for ratings on the interpersonal and modified antisocial facets reduced the association between criminal charges for violent offences and symptoms of cocaine dependence; controlling for ratings on a modified antisocial facetalso attenuated links between alcohol and cannabis dependence symptoms and history of charges for violent offences. These findings build on the sparse literature to date on the role of psychopathy traits on relationships between features of substance use disorders and violence. Given that the observed connection between substance dependence symptoms and charges for violent offences is partly accounted for by individual differences in psychopathy traits, it follows that effective treatment for those traits may be useful, perhaps essential to reducing links between features of some substance use disorders and violent offending.

Deformation and fluid flow history of a fractured basement hydrocarbon reservoir below the Sab'atayn Basin, Habban Field, Yemen

Fractured crystalline basement reservoirs are of increasing economic interest for oil and gas exploration and subsurface fluid storage. The successful characterization of these reservoirs is commonly challenged by their structural heterogeneity, complexity in fracture distribution and flow properties at multiple scales, and the difficulty of imaging fractures in exploration seismic. We analyzed the fracture geometry and fracture diagenetic attributes in two oriented cores from the Habban Field in the Late Jurassic Sab'atayn Basin (Yemen) to evaluate the multi-phase deformation history and fracture flow pathway evolution for (hydrothermal) fluids and hydrocarbons. Analyses included petrographic and fluid inclusion analysis of fracture-filling cements, and stable sulfur isotope analyses of fracture-filling pyrite.The Paleoproterozoic basement consists of amphibolite-facies metamorphic ortho- and paragneiss cut by several phases of Neoproterozoic granitoid intrusions. The investigated lithologies in the drill cores comprise (1) epidote quartzite, (2) amphibolite, (3) monzogranite, (4) meta-arkose, and (5) quartz-feldspar porphyry. These lithologies show an inhomogeneous fracture network that is partially cemented. Ediacaran brittle-ductile deformation (D1) recognized only within a Pan-African monzogranite lead to cataclasis and porosity generating alteration. Late Jurassic – Early Cretaceous extension (D2) related to the break-up of Gondwanaland and the formation of the Sab'atayn Basin is found in all lithologies and likely resulted in pervasive quartz cementation. Late Jurassic fractures parallel to the NW-SE trending long axis of the Sab'atayn Basin are best recognized in a strongly foliated amphibolites. Cenozoic extensional fracturing (D3) reactivated older structures, which probably formed during activity of the Neoproterozoic Najd Fault System and caused multi-phased (pyrite-(saddle) dolomite-calcite) fracture cementations. The sulfur isotope compositions of pyrite with δ34S values ranging between −17.4 and + 26.4‰ vs. V-CDT reflects the variability of the fluid source during sulphide mineral formation from hydrocarbon-rich hydrothermal solutions. Fluid inclusions indicate that cementation reactions occurred in a relatively narrow temperature field between 120 °C and 140 °C, ideal for hydrocarbon maturation. Our results demonstrate the potentially complex charge history of basement reservoirs, involving multiple phases of fracture formation and cementation, and fluid charge episodes.

New insights from petroleum systems modelling and magnetic analyses on the charge, fill and spill history of the Wytch Farm oil field, Wessex Basin, UK

Basin and petroleum systems modelling of the Wessex Basin, UK has been conducted to identify the maturation and migration events that charged the principal Bridport Sands and Sherwood Sandstone reservoirs at the Wytch Farm oil field. Modelling results have been compared with recent observations of magnetic enhancements at oil-water contacts (OWCs) and possibly paleocontacts (PCs) in Wytch Farm reservoirs, to assess the use of magnetic OWCs to help calibrate petroleum systems models and provide insights into the migration history of the Wessex Basin. The model predicts the Blue Lias source rock only reached maturity to the south of the Purbeck Fault, with hydrocarbon generation initiating in the Late Jurassic and peaking in the Late Cretaceous, requiring lateral migration to Wytch Farm using the Bridport Sands as the main carrier bed. Cross-fault and northward migration occurred through conduits at Creech, Bushey Farm and in offshore areas, which charged the principal structures at Wytch Farm. A ∼20 km wide Late Cretaceous juxtaposition between the Bridport Sands and Sherwood Sandstone in the hangingwall and footwall of the Purbeck Fault, respectively, led to the charging of the Sherwood Sandstone reservoir. A basin-wide Cenozoic easterly tilt of ≤1⁰ caused a westerly hydrocarbon remigration, has shifted the Bridport Sands and Sherwood Sandstone Wytch Farm structures to the west, and drastically reduced the size of Bridport Sands accumulations. There is a strong correlation between the predicted depths of Late Cretaceous and present-day OWCs with magnetic enhancements in drill cores. Multiple magnetic enhancements above the OWC at the Wareham oil field indicate the Cenozoic tilting event was periodic, forming multiple stable OWCs, with migration modelling suggesting a spill from Wytch Farm.

Drugs, guns, and violent crime in California

BackgroundThere is evidence linking use of controlled substances with perpetration of interpersonal violence. While the United States constitution protects the right to own a firearm, federal law prohibits firearm purchase and possession by persons believed to be at high risk for violence, including those who use controlled substances unlawfully. MethodsWe report here the results of a 13-year prospective observational study on the risk of violent crime associated with a history of criminal drug charges in a cohort of 79,678 legal purchasers of handguns in California in 2001. The main outcomes were post-purchase charges for any violent crime, violent Crime Index crimes (murder, rape, robbery, aggravated assault), and firearm-related violent crimes. The main exposure of interest was a history of pre-purchase charge(s) for drug-related offenses; we examined as a secondary exposure a history of marijuana-related charges. We estimated adjusted hazard ratios (aHR) with 95 % confidence intervals (CI) using Cox proportional hazards multiple events models. ResultsWe found that legal handgun purchasers in California with a history of drug-related charges, even those with marijuana charges only, had triple the risk of a post-purchase violent crime charge compared to purchasers with no criminal charges (drug charges only: aHR=2.9, 95 % CI 2.2–3.8; marijuana charges only: aHR=3.3, 95 % CI 1.8–6.0). In addition, a criminal history of drug charges only vs. no criminal history was associated with increased risk of one or more violent crime charges after the first post-purchase arrest event (aHR=1.6, 95 % CI 1.2–2.3). ConclusionIt is incumbent on researchers and policy makers to understand the nature and causes of this risk in order to take effective steps towards mitigation.

Middle Class African American Parents’ Aspirations for Rigor and Reading Curriculum During the Pandemic Era in Detroit Schools

This community-based research study examined the perspectives of African American parents of middle-class economic status who participated in a social network pertaining to school choice decisions during the pandemic era of virtual schooling. Their residency and school choices emerged against the grain of urban schools that have racially charged histories and decades of residential mobility trends. I examined parents’ aspirations for academic rigor and perspectives of literacy practices at select schools as well as public school district official perspectives of supporting the enrollment process and attracting families to the district. Parent interview and survey data revealed confidence in public, private, and charter school selections prior to enrolling, but uncertainty with the virtual literacy curriculum once enrolled in school. School district official interviews revealed enhanced awareness of parents’ concerns surrounding school choice and need to be proactive to the needs of middle-class families.

State-of-Health Estimation of Lithium-ion Batteries Based on Singular Value Decomposition and an Improved Group Method of Data Handling

Lithium-ion batteries are complex electrochemical systems, and the degradation of their state of health (SOH) is a nonlinear process. Accurate SOH estimation is critical to lithium-ion battery life and safety. This paper uses a data-driven approach to study SOH estimation of lithium-ion batteries. Firstly, this paper uses the singular value decomposition (SVD) method to extract features from the battery charging history data. Secondly, the particle swarm optimization (PSO) algorithm is used to optimize the parameter configuration of the group method of data handling (GMDH). Finally, the SOH estimation is completed using the optimized GMDH. The results show that the proposed PSO-GMDH estimation model maintains an error within 0.89% for estimating its subsequent SOH using historical data of a certain battery, and maintains an error within 0.5% for estimating the SOH of another battery of the same model using historical data of multiple batteries. At the same time, the results also show that the PSO-GMDH estimation model has higher estimation accuracy than the GMDH model without parameter optimization.

Cystic Endometrial Hyperplasia and Pyometra Complex in a Bitch

A 11 years old German Shepherd bitch with the history of abdominal distension, vomiting, and purulent vaginal dis charge was presented to Veterinary Clinical Complex, DUVASU, Mathura. Haematological examination revealed increase in total erythrocyte count and total leucocyte count while decrease in platelet count. The condition was treated with ovariohysterectomy and histopathological examination revealed the condition as cystic endometrial hyperplasia with pyometra complex.

Early phase psychosis and criminal conviction in United States adults.

Individuals experiencing early phase psychosis (EPP) are at increased risk for legal involvement. In prior studies, between 14% and 75% of individuals with EPP reported a history of criminal offending behaviour, criminal charges, or criminal convictions. To better understand the frequency of criminal conviction in a specialty treatment clinic serving EPP clients, the research team supplemented self-reported data from the clinic intake with information from publicly available databases. In this sample of 309 adults, approximately one quarter of patients (n = 76) self-reported a history of arrest, incarceration, probation, or parole within 6 months of enrolment in a treatment clinic. The research team expanded upon this and collected data from a public database of court proceedings in Indiana for all clinic participants before and after enrolment. Thirty-nine percent (n = 122) had three or more traffic tickets or a conviction for an ordinance violation, misdemeanour, or felony in the state of Indiana as an adult. This is over two times the national average. Drug and alcohol related convictions were the most common single conviction type, and 29% (n = 89) of subjects experienced at least one incarceration. These data highlight the need for specialty clinics to partner with professionals with expertise in the prevention and management of criminal behaviour. Future studies should examine risk factors for individuals experiencing EPP and criminal conviction.

In-situ calcite U-Pb ages and absolute timing of oil charge events: A case study of ultra-deep carbonate reservoirs in the Shunbei oilfield, Tarim basin, Northwest China

To accurately determine the timing of hydrocarbon charging events in petroleum systems is important but often challenging. Traditional methods for establishing the timing of these events in tectonic complex basins frequently suffer from unreliability due to uncertain burial and/or thermal histories, as well as the poor identification of inclusion assemblage. Recently developed calcite U-Pb dating has been proven to be a valuable tool for precisely determining the timing of these events, thus enhancing our understanding of the charging histories. We integrated oil-inclusion fluorescence analysis with in-situ calcite U-Pb dating, focusing on calcite fabrics hosting primary oil inclusions, to quantitatively constrain the oil charging timing of the SHB no.1 and no.5 fault zones in the Shunbei oilfield. The fluorescence spectra of oil inclusions suggested the presence of up to three discrete charging events in these fault zones. Calcite U-Pb ages provide constraints on the timing of the first charging episode in the two fault zones, at approximately 478–469.2 Ma and ca. 447.4–424 Ma, respectively. Comparing the fluorescence spectra of reservoir oils and oil inclusions reveals that the primary charging episodes in the SHB no.1 and no.5 fault zones correspond to the latest and the earliest charging episodes, respectively. Furthermore, through a comparison of the equivalent reflectance of reservoir oils with the thermal maturation history of the Cambrian source rock, the former age can be estimated at ca. 120–0 Ma. Regions characterized by weaker late-stage fault activity exhibit a higher potential for hydrocarbon preservation in deeper reservoirs.

Hydrocarbon charging process of Ordovician strike‐slip fault zones in the Shunbei area, Tarim Basin, NW China

Ultra‐deep marine carbonate reservoirs is an important field for oil and gas exploration, and it is also a hot research topic in recent years. However, their hydrocarbon episodic charging model is still under debate up to now. A great breakthrough has been made in the newly discovered ultra‐deep fault‐karst oil reservoir in the Shunbei area of Tarim Basin. Based on quantitative gas chromatogram‐mass spectrometry, stable carbon isotopes of reservoir oils, microthermometry and confocal laser scanning analyses of fluid inclusions, the reservoir oil origin and hydrocarbon charging history in Shunbei No. 1, No. 5 and No. 7 strike‐slip fault zones are expounded. The results showed that the Ordovician reservoir oil derives from the source rocks within the Cambrian Yuertusi Formation deposited in a highly anoxic bottom water environment. There were four stages of hydrocarbon charging in the study area, in the late Caledonian, late Hercynian–Indosinian, middle Yanshanian and late Himalayan. During this period, the force‐field strength of the charged oil gradually decreased, and the early‐stage charged crude oil with low maturity and high force‐field strength preferentially accumulated in the Yijianfang Formation, while the late‐stage charged crude oil with high maturity and low force‐field strength preferentially accumulated in the Yingshan Formation. This study reveals the history and differences of petroleum accumulation in the Shunbei fault zones, which is significance for understanding the hydrocarbon distribution in ultra‐deep marine carbonate reservoirs.

Influence of reservoir oil charging on diagenesis and reservoir quality: An example from Dunlin Reservoir Sandstones, East Shetland Basin, North Sea, UK

The sandstone facies from two reservoir blocks (extensional fault walls) of the Dunlin Field have been studied to evaluate the impact of the reservoir charge history on the diagenesis and reservoir quality of these sandstones. The study has identified seven main reservoir sandstone facies (D1–D7) from the reservoir crestal block (oil leg) to the flank block (water leg). These sandstone facies exhibited similar diagenetic patterns, controlled by their depositional parameters, hence having the same porosity and permeability values in both reservoir blocks (legs) until hydrocarbon charging in the Late Cretaceous‐Pliocene. The burial and thermal model indicates that these reservoirs were charged at a temperature of 60–75°C during the 80–50 Ma and 95–100°C during the 10 Ma to Present, and significantly controlled the mesodiagenetic output, notably illite, and quartz authigenesis. The reservoir oil leg recorded a higher amount of recovered bitumen (ca. 95%) than the water leg (ca. 5%), indicating that hydrocarbon charging of the sandstone reservoir was progressive rather than instantaneous, first filling the water leg (palaeo‐oil leg). Subsequent leak‐off depleted this reservoir block and remigrated to fill the reservoir leg (palaeo‐water). The fluctuating oil charging and leakage between these two reservoir fault blocks modulated diagenetic alteration of these reservoir sandstones; hence is the cause of the minor disparity in porosity values between these reservoir legs contrary to the wide variation between conventional reservoir oil‐ and water‐legs distinguished by hydrocarbon emplacement with no such complex history. This study, therefore, demonstrates the importance of evaluating the depositional and diagenetic controls on reservoir quality and charging of hydrocarbon‐bearing sandstones for optimum oil production and recovery in clastic depositional settings.

스마트컨트랙트 기반 전기차 배터리 충전이력 관리 메커니즘

스마트컨트랙트 기반 전기차 배터리 충전이력 관리 메커니즘