bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterizing and modeling the Upper Jurassic Arab-D reservoir using outcrop data from Central Saudi Arabia
Authors: Eltom Hassan , Abdullatif Osman , Makkawi Mohammed , Abdulraziq Asaad 
Published: October 2021

ABSTRACTOutcrop analogs are used to improve the characterization of reservoir stratigraphy, to understand subsurface facies architecture and heterogeneity, and to overcome the limitations associated with large inter-well spacing within individual oil fields. This study characterized and modeled outcropping strata equivalent to the Upper Jurassic Arab-D carbonate reservoir in Central Saudi Arabia. The study presents qualitative and quantitative sedimentological and petrographic descriptions of lithofacies associations and interprets them within a high-order stratigraphic framework using geostatistical modeling, spectral gamma-ray, geochemistry, petrography and micropaleontology. The sedimentological studies revealed three lithofacies associations, which are interpreted as a gentle slope platform depositional environment comprising nine high-frequency sequences. The biocomponents of the study area show a lower degree of diversity than the subsurface Arab-D reservoir; however, some key biofacies are present and provide indications of the nature of the paleoenvironments. The geochemical results show a strong correlation between the major and trace elements and the reservoir facies, and suggest that the concentrations of elements and their corresponding spectral gamma-ray logs follow the same general upward-shoaling pattern. The 3-D geocellular model captures small-scale reservoir variability, which is reflected in the petrophysical data distribution in the model. This investigation increases the understanding of the stratigraphy of the Arab-D reservoir and provides a general framework for zonation, layering, and lateral stratigraphic correlations.
Eocene oil shales from Jordan - their petrography, carbon and oxygen stable isotopes
Authors: Hussein Mohammad Ali , Alqudah Mohammad , van den Boorn Sander , Kolonic Sadat , Podlaha Olaf G. , Mutterlose Jörg 
Published: October 2021

ABSTRACT
Sediment petrographic studies combined with carbon and oxygen stable-isotope analyses are considered to be powerful tools in deciphering the depositional and diagenetic history of carbonate rocks. These studies have been found valuable for understanding the environmental controls and global changes of climate and oceanography. Two cores of Eocene bituminous marls (OS-22 and OS-23) from central Jordan with thicknesses of 222.4 m and 256.3 m, respectively, were logged. A total of 103 thin sections were analyzed for sediment petrographic investigations. Another 295 bulk rock samples from Core OS-23 were selected for stable-isotope analysis (δ13C, δ18O). The two cores show similar lithologic variations that correspond to third-order sea-level changes. The sediment petrographic study reveals the presence of six major microfacies that range from mudstones to grainstones. The distribution of these six types of microfacies in the two cores indicates an overall shallow-marine environment in an interior carbonate-platform setting. Within this environment, conditions fluctuated between open and restricted marine. The stratigraphic variability of the carbon-isotope data of Core OS-23 reflects a highly dynamic depositional system that exhibits a variable rate of organic matter accumulation in the sediments, which can be directly linked to the interaction between primary organic-matter burial and oxidative weathering of reworked organic matter. Within the overall diagenetically controlled δ18Ocarb profile an excursion is observed for a specifically enriched organic matter interval. This excursion is believed to coincide with the Middle Eocene Climatic Optimum (MECO), suggesting that next to seawater, porewaters were influenced by this event and making it the first record of this event in the region.
Lithofacies, diagenesis and reservoir quality of Upper Shu’aiba reservoirs in northwestern Oman
Authors: Al Habsi Naima , Al Shukaili Mohammed , Al Tooqi Sabah , Ehrenberg Stephen N. , Bernecker Michaela 
Published: October 2021

ABSTRACTCore and log data from Lower Cretaceous limestones of the Upper Shu’aiba Member were used to characterize the distribution of lithofacies, clay and porosity within two low-angle clinoforms that form the reservoirs for an oilfield of northwestern Oman. Data from 15 vertical wells, including four with core, and four horizontal well cores were projected into a dip-oriented cross-section derived from a static reservoir model as a basis for visualizing the above variations. Each clinoform consists of a basal “argillaceous zone” and a thicker “reservoir zone” of clean limestone, together reflecting fourth-order cycles of progradation along the margin of the Bab intra-shelf basin. Lithofacies vary in a proximal direction from mudstone and wackestone (mid-ramp) to mud-dominated packstone (slope) to mud-rich floatstone, rudstone and boundstone (ramp crest) and are arranged in a pattern of decreasing water depth and increasing energy both upwards and landward within each clinoform. In contrast, the reservoir zone of a younger clinoform from a nearby oilfield consists of well-sorted grainstone and grain-dominated packstone, illustrating the wide range of depositional conditions that occurred in the ramp-crest facies belt of different units.Except within the proximal extent of the younger clinoform, where values are transitional toward reservoir zone values, the argillaceous zones have total porosity mostly &lt; 10% and baseline-normalized gamma-ray (GR) activity &gt; 23 API units, reflecting clay contents of around 10–18%. In contrast, most parts of the reservoir zones have GR of 15–23 API units and porosity of 10–35%. Higher clay content is suggested to be linked with lower porosity through facilitation of both mechanical and chemical compaction, the latter providing a local supply of calcite cement. XRD analyses show that the clays are kaolin, illite/smectite and illite, similar to the clays in the overlying Nahr Umr shale. Most former macropores have been filled by blocky calcite cement in the main oilfield studied, but all lithofacies have similar wide ranges of total porosity of 8% to &gt; 30%.The cores were also studied for evidence of diagenesis related to the contact with the overlying Nahr Umr Formation, but profiles of stable-isotope ratios, bulk-rock strontium, petrography and porosity-permeability data show no trends indicative of upward-increasing meteoric diagenesis below this sequence boundary. Meteoric leaching could nevertheless be pervasive throughout the Upper Shu’aiba reservoirs, at least partially accounting for extensive aragonite dissolution and low Sr and δ18O values. Two of the cores show trends of upwards-increasing bulk-rock uranium, manganese and iron, possibly indicative of sea-floor authigenesis. In addition, saddle dolomite near the tops of these cores may reflect late influx of magnesium derived from clay in the Nahr Umr Formation.
New microplanktonic biostratigraphy and depositional sequences across the Middle–Late Eocene and Oligocene boundaries in eastern Jordan
Authors: Farouk Sherif , Faris Mahmoud , Ahmad Fayez , Powell John H. 
Published: October 2021

ABSTRACTThe first detailed calcareous nannofossil and planktonic foraminiferal biostratigraphic and integrated lithofacies analyses of the Eocene–Oligocene transition at the Qa’ Faydat ad Dahikiya area in the Eastern Desert of Jordan, on the border with Saudi Arabia, is presented. Three calcareous nannofossil zones namely: Discoaster saipanensis (NP17), Chiasmolithus oamaruensis (NP18) and Ericsonia subdisticha (NP21), and three planktonic foraminiferal zones: upper part of Truncorotaloides rohri (E13), Globigerinatheka semiinvoluta (E14) and Cassigerinella chipolensis/Pseudohastigerina micra (O1) are identified.Calcareous nannofossil bioevents recorded in the present study show numerous discrepancies with the Standard biostratigraphic zonal schemes to detect the Middle/Upper Eocene boundary (e.g. the highest occurrences (HOs) of Chiasmolithus solitus, C. grandis, and lowest occurrences (LOs) of C. oamaruensis, Isthmolithus recurvus are not considered reliable markers for global correlation). The Middle/Upper Eocene boundary occurs in the current study above the extinctions of large muricate planktonic foraminifera (large Acarinina and Truncorotaloides spp.) which coincide within the equivalent calcareous nannofossil NP18 Zone. These microplanktonic bioevents seem to constitute more reliable markers for the base of the Upper Eocene in different provinces. The uppermost portion of the Middle Eocene is characterized by an observed drop in faunal content and, most likely, primarily denotes the effect of the major fall in eustatic sea level.A major unconformity (disconformity) marked by a mineralized hardground representing a lowstand is recorded in the present study at the Eocene–Oligocene transition that reveals an unexpected ca. 2.1 Myr duration, separating Eocene (NP18/E14 zones) from Oligocene (NP21/O1 zones). Furthermore, the microfossil turnover associated with a rapid decline of the microfossil assemblages shows a distinct drop in diversity and abundance towards the Eocene/Oligocene unconformity and is associated with a sharp lithological break marked, at the base, by a mineralized hardground representing a major sequence boundary. These bioevents, depositional sequences and the depositional hiatus correlate well with different parts of the Arabian and African plates, but the magnitude of the faunal break differs from place to place as a result of intraplate deformation during the regional Oligocene regression of Neo-Tethys on the northern Arabian Plate. The presence of the Lower Oligocene shallow-marine calcareous planktonic assemblages in the study area indicate that communication between the eastern and western provinces of the western Neo-Tethys region still existed at this time.
Geologic Structure, Mineralogy, and Geochemistry of the Nerunda Gold Ore Field (Northern Transbaikalia)
Authors: Chetvertakov I.V. , Vanin V.A. , Demin I.A. 
Published: October 2021

Abstract
—We consider the geologic structure of the Nerunda gold ore field located in the Nerunda–Mama ore district in northern Transbaikalia. Gold–quartz low-sulfide formation and ore-bearing carbonate-terrigenous strata and intrusive complexes are briefly described. An ore complex of beresite–listvenite metasomatites hosting carbonate–quartz veins and vein–veinlet zones is characterized. Two stages of ore formation have been recognized. Anomalous geochemical associations and the composition of ore mineralization typical of these stages have been established. Mineralogical and geochemical studies of gold-bearing metasomatites of the Nerunda ore field were carried out. The known geochemical and mineralogical search criteria used for the assessment of the erosion zone level of gold deposits were applied to the geologic conditions of the Nerunda ore field and the Nerunda–Mama gold ore district as a whole. The emphasis was made on the express assessment of the erosion zone level at the early stage of prospecting. We draw a conclusion about the gold potential of the poorly studied ore objects at depth and give guidelines for the following geological prospecting.
Technology Focus: Field Development (September 2021)
Authors: Garmeh Reza 
Published: October 2021

The digital transformation that began several years ago continues to grow and evolve. With new advancements in data analytics and machine-learning algorithms, field developers today see more benefits to upgrading their traditional development work flows to automated artificial-intelligence work flows. The transformation has helped develop more-efficient and truly integrated development approaches. Many development scenarios can be automatically generated, examined, and updated very quickly. These approaches become more valuable when coupled with physics-based integrated asset models that are kept close to actual field performance to reduce uncertainty for reactive decision making.
In unconventional basins with enormous completion and production databases, data-driven decisions powered by machine-learning techniques are increasing in popularity to solve field development challenges and optimize cube development. Finding a trend within massive amounts of data requires an augmented artificial intelligence where machine learning and human expertise are coupled.
With slowed activity and uncertainty in the oil and gas industry from the COVID-19 pandemic and growing pressure for cleaner energy and environmental regulations, operators had to shift economic modeling for environmental considerations, predicting operational hazards and planning mitigations. This has enlightened the value of field development optimization, shifting from traditional workflow iterations on data assimilation and sequential decision making to deep reinforcement learning algorithms to find the best well placement and well type for the next producer or injector. Operators are trying to adapt with the new environment and enhance their capabilities to efficiently plan, execute, and operate field development plans. Collaboration between different disciplines and integrated analyses are key to the success of optimized development strategies.
These selected papers and the suggested additional reading provide a good view of what is evolving with field development work flows using data analytics and machine learning in the era of digital transformation.
Recommended additional reading at OnePetro: www.onepetro.org.
SPE 203073 - Data-Driven and AI Methods To Enhance Collaborative Well Planning and Drilling-Risk Prediction by Richard Mohan, ADNOC, et al.
SPE 200895 - Novel Approach To Enhance the Field Development Planning Process and Reservoir Management To Maximize the Recovery Factor of Gas Condensate Reservoirs Through Integrated Asset Modeling by Oswaldo Espinola Gonzalez, Schlumberger, et al.
SPE 202373 - Efficient Optimization and Uncertainty Analysis of Field Development Strategies by Incorporating Economic Decisions in Reservoir Simulation Models by James Browning, Texas Tech University, et al.
Generative Well-Pattern Design Presents Opportunities To Reduce Drilling Expenditures
Authors: Carpenter Chris 
Published: October 2021

This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 203152, “Generative Well-Pattern Design Applied to a Giant Mature Field Leads to the Identification of Major Drilling Expenditure Reduction Opportunities,” by Maddalen Lepphaille, Total; Arthur Thenon, Modis; and Pierre Bergey, Total, et al., prepared for the 2020 Abu Dhabi International Petroleum Exhibition and Conference, Abu Dhabi, held virtually 9–12 November. The paper has not been peer reviewed.
A generative well-pattern-design (GWPD) work flow was benchmarked against traditional manual designs to leverage three reservoir-development planning opportunities applicable to a giant mature Middle Eastern carbonate field. People remained central in ensuring efficient problem setup and exploration guidance, but the work flow proved able to identify substantially better patterns than the traditional approach for each of the opportunities at the cost of only a few hundred simulations.

GWPD Overview
The work flow used to tackle the different problems of this study, which the authors call the GWPD “well-improvement scheme” (WISH), consists of the following steps. Each step is detailed in the complete paper.
1. Definition of design space
2. Constraint of design space
3. Qualification of design space
4. Nondominated sorting (a specific ranking of all of the cells of the con-strained design space according to the value of their quality indicators)
5. Candidate design investigation
6. Investigation of preferred designs
7. Optimization of preferred design

GWPD Application
Context. The application study was con-ducted at the beginning of the industrialization of WISH, a proprietary software tool dedicated to GWPD. The authors call the work flow GWPD-WISH.
In the studied oil field, more than 400 oil producers and water- or gas-injector strings have been drilled from approximately 100 platforms in a series of reservoirs. The study focused upon two specific reservoirs holding most of the field reserves. These reservoirs are developed with peripheral water injection and gas injection into the gas cap. According to the latest development plan, hundreds of wells will be drilled during the next 40 years in order to maintain a production plateau.
The context was deemed favorable because a 3D gridded dynamic reservoir model was available, the geology and development history defined a large and complex design problem, and large liquid hydrocarbon reserves were thought to remain.
While the software and method used enables considering an ensemble of realizations capturing reservoir uncertainties, only a single history-matched realization of the model was available. Consequently, the study did not deal with reservoir uncertainties.
Immunohistochemical Evaluation and Prognostic Value of Monocarboxylate Transporter 1 (MCT1) and 4 (MCT4) in T-cell Non-Hodgkin Lymphoma
Authors: Zhao Hu , Chen Yuan , Liao You-Ping , Chen Hai-Mei , Yang Qiu-Hong , Xiao Yin , Luo Jing , Chen Zhen-Zhen , Yi Lai , Hu Guo-Yu 
Published: October 2021

Abstract
Tumor cells often exhibit the Warburg effect, wherein, they preferentially undergo glycolysis over oxidative phosphorylation for energy production. Monocarboxylate transporter 1 (MCT1) and 4 (MCT4) are critical symporters mediating lactate efflux and preventing intracellular acidification during tumor growth. Numerous studies have focused on inhibiting MCT1 or MCT4 in various cancers. However, its role in T-cell lymphoma (TCL) is not yet investigated owing to the low incidence of TCL. This study was designed to investigate the expression of MCT1/MCT4 in patients with TCL and determine their prognostic value in this cancer. We performed immunohistochemistry to evaluate the expression level of MCT1/MCT4 in 38 TCL tissue samples and then compared their expression among different TCL subgroups, which were formed based on different clinical characteristics. Survival analysis was performed to evaluate the relationship between MCT1/MCT4 expression and both overall survival (OS) and progression-free survival (PFS). Our results revealed that MCT1 and MCT4 expression was significantly increased in TCL tissues compared to the control group. In addition, increased MCT1 expression associated with the female sex, advanced disease stage, increased serum LDH, Ki-67 at ≥50%, and intermediate or high-risk groups as categorized by the International Prognostic Index (IPI) score. We also found that increased MCT1 expression may be associated with reduced OS and PFS. In conclusion, MCT1 and MCT4 are overexpressed in patients with TCL, and may predict poor prognosis. MCT1 inhibition might be a novel treatment strategy for TCL, and further preclinical trials are required.
Mesenchymal Stem Cells Ameliorate Mitochondrial Dysfunction in α - cells and Hyperglucagonemia in type 2 Diabetes via SIRT1/FoxO3a Signaling
Authors: Song Jia , Wang Lingshu , Guo Xinghong , He Qin , Cui Chen , Hu Huiqing , Zang Nan , Yang Mengmeng , Yan Fei , Liang Kai , Wang Chuan , Liu Fuqiang , Sun Yujing , He Falian , Sun Zheng , Hou Xinguo , Lai Hong , Chen Li 
Published: October 2021

Abstract
Background: Dysregulation of α-cells results in hyperglycemia and hyperglucagonemia in type 2 diabetes mellitus (T2DM). Mesenchymal stem cell (MSC)-based therapy increases oxygen consumption of islets and enhances insulin secretion. However, the underlying mechanism for the protective role of MSCs in α- cell mitochondrial dysfunction remains unclear. Here, we evaluated the efficacy and molecular mechanisms of human umbilical cord MSCs (hucMSCs) on α-cell mitochondrial function and glucagon secretion in T2DM.Methods: hucMSCs were used to treat two kinds of T2DM mice and αTC1-6 cells to explore the role of hucMSCs in improving α-cell mitochondrial dysfunction and hyperglucagonemia. Plasma and supernatant glucagon were detected by enzyme-linked immunosorbent assay (ELISA). Mitochondrial function of α-cells was assessed by the Seahorse Analyzer. To investigate the underlying mechanisms, Sirtuin 1 (SIRT1), Forkhead box O3a (FoxO3a), glucose transporter type1 (GLUT1), and glucokinase (GCK) were assessed by western blotting analysis.Results: In vivo, hucMSC infusion improved glucose and insulin tolerance, as well as hyperglycemia and hyperglucagonemia in T2DM mice. Meanwhile, hucMSC intervention rescued islet structure and decreased α- to β-cell ratio. Consistently, glucagon secretion from αTC1-6 cells was inhibited by hucMSCs in vitro. Meanwhile, hucMSC treatment activated intracellular SIRT1/FoxO3a signaling, promoted glucose uptake and activation, alleviated mitochondrial dysfunction, and enhanced ATP production. However, transfection of SIRT1 small interfering RNA (siRNA) or the application of SIRT1 inhibitor EX-527 weakened the therapeutic effects of hucMSCs on mitochondrial function and glucagon secretion.Conclusions: Our observations indicate that hucMSCs mitigate mitochondrial dysfunction and glucagon hypersecretion of α-cells in T2DM via SIRT1/FoxO3a signaling, which provides novel evidence demonstrating the potential for hucMSCs in treating T2DM.
Safety and Feasibility of Novel Reconstruction Method Using Long and Narrow Cobra- Head- Shaped Gastric Tube in Laparoscopic Proximal Gastrectomy for Cancer
Authors: Ueda Yoshitake , Kawasaki Takahide , Tanabe Sanshi , Suzuki Kosuke , Ninomiya Shigeo , Shiroshita Hidefumi , Etoh Tsuyoshi , Inomata Masafumi , Shiraishi Norio 
Published: October 2021

Abstract
Background. To clarify the safety and feasibility of laparoscopic proximal gastrectomy (LPG) with our novel reconstruction methods, clinical outcomes of this LPG were evaluated and compared to those of LPG with our conventional method. Methods. Novel method is a reconstruction with a long and narrow gastric tube with widening of the proximal side of the gastric tube created by linear stapler. Esophagogastrostomy is performed by direct anastomosis with overlap method between the posterior wall of the esophagus and anterior wall of the gastric tube using a linear stapler. In conventional method, direct anastomosis between the esophagus and a gastric tube by a circular stapler was performed. Short- and long-term outcomes of a novel method were compared with those of conventional method. Results. A total of 39 patients whom LPG was performed were enrolled in this retrospective study. The amount of blood loss in the Novel method group (n=30) was significantly less than those in the Conventional method group (n=9) (40 vs. 110 ml, p<0.01). No cases of anastomotic leakage and stenosis were observed in both groups. The cases of postoperative reflux esophagitis at 1 year after operation in the Novel group were less than those in the Conventional group (10% vs. 33%). In the Novel group, postoperative recurrence was observed in 2 patients (7%). Conclusions. LPG with novel reconstruction method using long and narrow cobra- head-shaped gastric tube can be easily performed, and may be feasible for the treatment of gastric cancer in the upper third of the stomach.