bluuebunny/crossref_metadata_2025_split huggingface dataset:
Designing a Robust ASP Formulation for The Kuparuk Field
Authors: Torres Lopez David Enrique , Burns Bobby J , Solairaj Sriram , Jensen Trond B , Needham Riley 
Published: August 2020

Abstract
This paper discusses surfactant, co-solvent, alkali and polymer (ASP) formulations developed for the Kuparuk Field in Alaska. This field is a mature conventional reservoir that exhibits favorable characteristics for surfactant flooding.
The formulations have been tested in the laboratory and in the field with good results. In core floods with live oil and reservoir core, oil saturation has been driven below 5% (Sorc) recovering more than 90% of the waterflood residual oil (Sorw). An ASP treatment, via a single well chemical tracer test, has yielded an Sorc of 1% recovering 96% of the Sorw in the field. However, the process of developing ASP formulations that effectively recover residual oil and represents a commercially viable ASP flood has been challenging. Driving the surfactant retention to low values has required the use of enhanced alkoxylated surfactants and co-solvents that provide low interfacial tension (IFT) micro-emulsions with low viscosity under broad salinity ranges. Kuparuk's rock mineralogy has also played an important role due its heterogeneity and high clay content. Clays with iron bearing minerals and significant ionic exchange have required a systematic study to better understand the effect of reservoir rock on the surfactant treatment. The impact of calcium and magnesium released by the reservoir rock was of primary concern.
Significant results from the Kuparuk ASP formulation study are summarized. The performance of formulation components and their overall effect on surfactant retention, as well as rock mineralogy, are analyzed in detail. Experimental methodologies, analytical studies, and adequate core flood practices used to overcome challenges are also discussed. The lessons learned from this study have the potential to be used in other Alaskan fields, unlocking vast and valuable resources from mature reservoirs as well as new discoveries.
Applications of Rate and Pressure Transient Analysis in Huff-n-Puff Gas EOR for Unconventional Reservoirs
Authors: Haghshenas Behjat , Qanbari Farhad 
Published: August 2020

Abstract
Gas injection huff and puff (HnP) has been successfully applied in parts of Eagle Ford over the past few years. The success is attributed to gas and oil miscibility achieved by injection of gas at high pressure and rate in a contained hydraulic fracture system with a considerable of stimulated volume. Two key preliminary steps in gas HnP modeling include characterization of reservoir fluid (and its interaction with injected gas) and evaluation of hydraulic fracture system. This study focuses on simplified analytical tools for estimation of stimulated reservoir size from production data.
Rate-transient analysis (RTA) is a tool for identification of flow regimes and estimation of key performance metrics for multi-fractured horizontal wells. The flow regimes include enhanced fractured region (EFR), bilinear flow, transient linear flow, transitional flow, and boundary-dominated flow. In this study, the size of stimulated rock and total effective fracture area are estimated using an RTA method. Further, diagnostics fracture injection tests (DFITs) and pressure buildup tests are used to characterize the multi-fractured horizontal wells for the purpose of gas EOR evaluation. Inter-well communication test is used to quantify the conductivity of connecting fractures between communication wells.
This study helps the engineers and managers with reservoir and hydraulic fracture characterization and the screening process for gas HnP candidates. The outputs of these methods serve as first pass of SRV size for more detailed numerical modeling studies.
Effect of Biodegradation on CO2 Minimum Miscibility Pressure for the Frio Reservoir Fluids
Authors: Yuan Hua 
Published: August 2020

Abstract
The great Frio Salt-Dome oil fields dot the Texas coast south and southeast of Houston. Over 2.4 billion barrels of oil have been produced since these fields were discovered in the 1920s. Currently, oil is produced at water cuts higher than 95% from most of these fields. With deteriorating water flood economics, over 1.7 billion barrels of remaining oil are left to be targeted by CO2 flood. CO2 floods were successfully developed in a few Frio Fields. The current (on 1/1/2020) combined cumulative oil production from the Oyster Bayou and the West Hastings CO2 floods is over 30 MMSTB. Even with the high volume of remaining oil and the great success of the CO2 floods, some of the Frio fluids are a challenge for CO2 flooding due to biodegradation of the oils. Local displacement efficiency depends on minimum miscibility pressure (MMP). Displacement efficiency is over 90% when operating pressure is above the MMP and drops significantly when operating pressure is lower than the MMP. In the Frio fields, however, the measured MMPs from the existing slimtube experiments were significantly deviated from what is estimated from most of the CO2 correlations. Therefore, these correlations can’t be used in estimating MMP during the screening phase of CO2 flood in the Frio fields. In this paper, the characteristics of different Frio fluids is shown with gas chromatograms and compositional analysis. The cause of biodegradation and its effect on CO2 MMPs in these Frio fields is discussed. A new parameter with the ratio of xC7+xC2−4 is identified to be an indicator of the level of biodegradation for the Frio oils. This parameter along with molecular weight (MW) of C5+ or C7+ and reservoir temperature is recommended as the new parameters for generating an improved CO2 MMP correlation for a general oil, while a simple CO2 MMP correlation is also presented for the Frio oil fields. Furthermore, guidance on screening fields from reservoir fluid aspects in the Frio Zone for CO2 flood is provided.
Proxy Based Assisted History Matching and Well Spacing Optimization in Shale Gas Development of a Real Field Case
Authors: Liu Chuxi , Yu Wei , Chang Cheng , Li Qiwei , Sepehrnoori Kamy 
Published: August 2020

Abstract
A robust and reliable workflow for well spacing optimization in shale reservoirs development incorporating various types of uncertainties and detailed economics analysis is paramount to achieve a sustainable unconventional production. In this study, we show a novel well spacing optimization workflow based on the results of assisted history matching and apply it to a real shale gas well, incorporating uncertainty parameters such as matrix permeability, matrix porosity, fracture half-length, fracture height, fracture width, fracture conductivity and fracture water saturation. The input ranges of these parameters are 10 nd to 1000 nd, 0.038 to 0.083, 200 ft to 780 ft, 25 ft to 65 ft, 0.1 ft to 4 ft, 10 md-ft to 200 md-ft, and 0.5 to 0.9 respectively and are determined from field experience and exisiting information. Results from assisted history matching are gathered with a total of 60 HM (history matching) solutions out of 325 runs that meets the criteria of BHP (bottomhole pressure) error less than 25% and WGR (water gas ratio) error less than 60%. A total of 1548 proxy solutions out of 100,000 samplings are obtained from MCMC (markov chain monte carlo) algorithm. Embedded discrete fracture model (EDFM) is used to model hydraulic fractures along with a commercial reservoir simulator. The use of greatly facilitates the modelling process of hydraulic fractures compared to the LGR (local grid refinement) method. The uncertainty parameter distributions from our workflow is matching the posterior distribution obtained from assisted history matching. It is found out that the optimal well spacing is approximately 885 ft, with an estimated net present value (NPV) of 6.67 million dollars. Economic uncertainty evaluation is performed and it is discovered that the NPV distribution obtained from the history matching solution is more concave than the results obtained from KNN (k-nearest neighbor) proxy prediction. The optimal well spacing of 885 ft obtained from this workflow is matching closely with the field experience of approximately 1000 ft. The P50 of the NPV distributions of five spacing (1550 ft, 1033 ft, 775 ft, 620 ft, and 517 ft) are 4.04, 5.91, 7.35, 6.42, and 5.44 million dollars respectively. Gas estimated ultimate recovery per well (P50) for the abovementioned spacings are 3070, 3020, 2945, 2750, and 2565 million cubic feet respectively. There is a drastic drop of gas estimated ultimate recovery per well about 6.6% going from a spacing of 775 ft to 620 ft, indicating the onset of well interference between these distances’ range. The practicality and the convenience of our workflow make it possible to be applied to any shale gas well.
Investigation of Reservoir Permeability Impairment When Drilling with Nano Treated Drill-in Mud System
Authors: Okoro Emmanuel E. , Okafor Ikechukwu S. , Sanni Samuel E. , Obomanu Tamunotonjo , Oguntade Tomiwa , Orodu Oyinkepreye D. 
Published: August 2020

Abstract
A reservoir non-damaging Nano treated aqueous-based drilling fluid was proposed. The study was carried out to obtain a drilling ﬂuid with rheological properties able to keep cuttings in suspension for transport to the surface, minimize ﬁltration and ﬂuid loss. These rheological properties were also predicted using Artificial Neural Network (ANN) due to limitations of existing flow models in predicting Nano-based mud systems. Diﬀerent concentrations of the Nanoparticles were added to these suspensions of water to act as filtration loss materials. A total number of 160 data were used to train the ANN which consists of both the input data and output data acquired from the experiment. The study shows good agreement between experimental data and the artificial neural network prediction of plastic viscosity (PV) and yield point (YP), for multiwall carbon nanotubes (MWCNT) formulated muds. The addition of different concentrations of MWCNT (0.5 – 3 g) as rheology modifier-additive was put to test in a field applicable aqueous mud system. The developed neural network has a Mean Absolute Deviation (MAD) of 0.61529, MSE of 0.57174, Root Mean Square Error (RMSE) of 0.75614 and Mean Absolute Percentage Error (MAPE) of 1.92331 for the predicted plastic viscosity and yield point which are all indicative of good levels of accuracy. It is important to explore the reservoir impairment mechanisms so as to improve and optimize the reservoir performance during the production of hydrocarbons. Having satisfied all the conditions, permeability was determined using Darcy's equation. A reduction in permeability within the range of 12 – 16 mD was recorded for the Nano treated water-based mud system.
The need for home care physicians in Japan – 2020 to 2060
Authors: Iwata Hiroyoshi , Matsushima Masato , Watanabe Takamasa , Sugiyama Yoshifumi , Yokobayashi Kenichi , Son Daisuke , Satoi Yoshinao , Yoshida Eriko , Satake Sumiko , Hinata Yuki , Fujinuma Yasuki 
Published: August 2020

Abstract

Background Due to the fact that Japan faces the most elderly society in the world, the Japanese government has launched an unprecedented health plan to reinforce home care medicine and increase the number of home care physicians, which means that an understanding of future needs for geriatric home care is vital. However, little is known about the future need for home care physicians. We attempted to estimate the basic need for home care physicians from 2020 to 2060. Methods Our estimation is based on modification of major health work force analysis methods with previously reported official data. Two models were developed to estimate the necessary number of full-time equivalent (FTE) home care physicians: one based on home care patient mortality, the other using physician-to-patient ratio, working with estimated numbers of home and nursing home deaths from 2020 to 2060. Moreover, the final process considered and adjusted for future changes in the proportion of patients dying at home. Lastly, we converted estimated FTE physicians to an estimated head count. Results Results were concordant between our two models. In every instance, there was overlap of high- and low-estimations between the mortality method and the physician-to-patient method, and the estimates show highly similar patterns.Furthermore, our estimation is supported by the current number of physicians, which was calculated using a different method. Approximately 1.7 times (1.6 by head count) the current number of FTE home care physicians will be needed in Japan in the late 2030’s, peaking at 33,500 FTE (71,500 head count). However, the need for home care physicians is anticipated to begin decreasing by 2040. Conclusion The results indicate that the importance of home care physicians will rise with the growing elderly population, and that improvements in home care could partially suppress future need for physicians. After the late 2030’s, the supply can be reduced gradually, accounting for the decreasing total number of deaths after 2040. In order to provide sufficient home care and terminal care at home, increasing the number of home care physicians is indispensable. However, the unregulated supply of home care physicians will require careful attention in the future.
Trends in the incidence of diabetes mellitus: results from the Global Burden of Disease Study 2017 and implications for diabetes mellitus prevention
Authors: Liu Jinli , Ren Zhen-Hu , Qiang Hua , Wu Jine , Shen Mingwang , Zhang Lei , Lyu Jun 
Published: August 2020

Abstract
Backgroud: Diabetes mellitus is a common chronic disease and a severe public health issue. The incidence trends for type 1 diabetes (TIDM) and type 2 diabetes (T2DM) have rarely been studied on a global scale. We aimed to determine the temporal and geographical trends of diabetes globally.Methods: Data on diabetes mellitus, including incidence, prevalence from 1990 to 2017 were obtained from the 2017 Global Burden of Disease study. We calculated the estimated annual percentage changes (EAPCs) in age-standardized incidence rate (ASR) of diabetes mellitus according to sex, region, and disease type.Results: The worldwide incident cases of diabetes mellitus has increased by 102.9% from 11,303,084 cases in 1990 to 22,935,630 cases in 2017 worldwide, while the ASR increased from 233.58/100,000 persons (95% UI, 218.95–249.37) to 284.56/100,000 persons (95% UI, 262.17–309.71) in this period [EAPC=0.87, 95% confidence interval (CI):0.79–0.96]. The global ASRs of T1DM and T2DM both demonstrated significant increase during 1990-2017, with EAPCs of 0.34 (95% CI:0.30–0.39) and 0.89 (95% CI:0.80–0.97), respectively. The ASR trends also varied considerably by regions and countries. The increase in ASR was greatest in high sociodemographic index regions (EAPC=1.05, 95% CI:0.92–1.17) and lowest in low-SDI regions (EAPC=0.79, 95% CI:0.71–0.88).Conclusions: Both the number of incident cases and ASR of diabetes mellitus increased significantly during 1990-2017 worldwide, but the temporal trends varied markedly across regions and countries.
Genetic diversity and fingerprinting of 33 standard flue-cured tobacco varieties for use in distinctness, uniformity, and stability testing
Authors: He Binbin , Geng Ruimei , Cheng Lirui , Yang Xianbin , Ge Hongmei , Ren Min 
Published: August 2020

Abstract
Background: At present, the distinctness, uniformity, and stability (DUS) testing of flue-cured tobacco ( Nicotiana tabacum L.) depends on field morphological identification, which is problematic in that it is intensive, time-consuming, and susceptible to environmental impacts. In order to improve the efficiency and accuracy of tobacco DUS testing, the development of a molecular marker-based method for genetic diversity identification is urgently needed.

Results: In total, 91 simple sequence repeats (SSR) markers with clear and polymorphic amplification bands were obtained with polymorphism information content, Nei index, and Shannon information index values of 0.3603, 0.4040, and 0.7228, respectively. Clustering analysis showed that the 33 study varieties, which are standard varieties for flue-cured tobacco DUS testing, could all be distinguished from one another. Further analysis showed that a minimum of 25 markers were required to identify the genetic diversity of these varieties. Following the principle of two markers per linkage group, 48 pairs of SSR markers were selected. Correlation analysis showed that the genetic relationships revealed by the 48 SSR markers were consistent with those found using the 91 SSR markers.

Conclusions: The genetic fingerprints of the 33 standard varieties of flue-cured tobacco were constructed using 48 SSR markers, and an SSR marker-based identification technique for new tobacco varieties was developed. This study provides a reliable technological approach for determining the novelty of new tobacco varieties and offers a solid technical basis for the accreditation and protection of new tobacco varieties.
Alpha Thalassemia Genotypes in Kuwait
Authors: Adekile Adekunle , Sukumaran Jalaja , Thomas Diana , D'Souza Thomas , Haider Mohammad 
Published: August 2020

Abstract
Background: The frequency of the alpha thalassemia trait is approximately 40% in the Kuwaiti population, but there has been no comprehensive study of the prevalent alleles. This is a report of patients who were referred for molecular diagnosis over a 20-year period.Methods: This is a retrospective study of the a-globin genotypes obtained in the Hemoglobin Research Laboratory of the Department of Pediatrics, Kuwait University from 1994 to 2015. Genotyping was performed by a combination of PCR, allele-specific oligonucleotide hybridization and reverse dot blot hybridization (Vienna Lab Strip Assay).Results: Four hundred samples were characterized and analyzed from individuals aged <1 month to 80 years, with a median of 6 years from 283 unrelated families. Most (90.8%) were Kuwaiti nationals. The commonest genotype was homozygosity for the polyadenylation-1 mutation (αPA-1α/α PA-1α) in 33.3% of the samples, followed by heterozygosity (αα/α PA-1α) for the same mutation in 32.3%. PA-1 was therefore the most frequent allele (0.59). The frequency of the α0 (--MED) allele was 0.017. Rare alleles that were found in very low frequencies included α0 (--FIL) in a Filipino child, Hb Constant Spring, Hb Adana, and Hb Icaria.Conclusion: There is a wide variety of alpha thalassemia alleles among Kuwaitis, but nondeletional PA-1 is by far the most common cause of the moderate to severe HbH (β4 tetramer) disease phenotype. The α0 (–MED) allele is also encountered, which has implications for premarital counseling, especially for the possibility of having babies with alpha thalassemia major (Barts hydrops fetalis).
The effect of different doses of radiation on the morphogical, mechanical and chemical properties of the primary and permanent teeth—an in vitro study
Authors: Duruk Gülsüm , Acar Burçin , Temelli Öztun 
Published: August 2020

Abstract
Background. Radiotherapy, applied to the head and neck region, can cause radiation side effects such as reduction of saliva and radiation caries. The aim of this study was to perform an in vitro assessment of the effects of radiation therapy on the morphological, mechanical, and chemical properties of primary and permanent teeth. Methods. 92 extracted human teeth (46 impacted wisdom teeth, 46 primary molar teeth) were used. The teeth were divided into two directions: the mesiodistal direction and the vestibulolingual direction. The vestibular sections were used for the vickers analysis, and lingual sections were used for the Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES) analysis. The teeth in the experimental group were fixed to wax models. Each model had an equal number of teeth (n=7). The doses were applied to the teeth for 6 weeks; 5 week days and 2Gy daily. After the radiotherapy was conducted weekly, a wax model was taken from radiation reception. Along with the elemental contents (Na, K, Mg, P, and Ca) of the teeth, enamel and dentin microhardness was evaluated, and SEM analyzes were performed on 8 teeth. These teeth were compared with the other non-irradiated sections. Results. Radiation caused a decrease in microhardness of enamel and dentin(p<0.05). In the elemental analysis by ICP-OES, it was observed that there were decreases in all doses, while the highest decrease was in 60Gy dose(p<0.01). In the experimental groups, amorphous structures were encountered in SEM images. Conclusions. Radiation has negative effects on the teeth structure and additional studies are needed in this regard. This study indicates that radiotherapy patients are at a higher risk for dental caries.
Identification of a four-gene panel predicting overall survival for lung adenocarcinoma
Authors: Chunyu Li , Qizhong Long , Danni Zhang , Jun Li , Xianming Zhang 
Published: August 2020

Abstract
Background: Lung cancer is the most frequently diagnosed carcinoma and the leading cause of cancer-related mortality. Although molecular targeted therapy and immunotherapy have made great progress, the overall survival (OS) is still poor due to a lack of accurate and available prognostic biomarkers. Therefore, in this study we aimed to establish a multiple-gene panel predicting OS for lung adenocarcinoma. Methods: We obtained the mRNA expression and clinical data of lung adenocarcinoma (LUAD) from TCGA database for further integrated bioinformatic analysis. Lasso regression and Cox regression were performed to establish a prognosis model based on a multi-gene panel. Nomogram was built based on the model. The receiver operating characteristic (ROC) curve and the Kaplan–Meier curve were used to assess the predicted capacity of the model. The prognosis value of the multi-gene panel was further validated in TCGA-LUAD patients with EGFR, KRAS and TP53 mutation and a dataset from GEO. Gene set enrichment analysis (GSEA) was performed to explore potential biological mechanisms of a novel prognostic gene signature. Results: A four-gene panel (including DKK1, GNG7, LDHA, MELTF) was established as a prognostic indicator for OS of LUAD. The ROC curve revealed good predicted performance in both test cohort (AUC = 0.740) and validation cohort (AUC = 0.752). Each patient was calculated a risk score according to the model based on the four-gene panel. The results showed that the risk score was an independent prognostic factor, and the high-risk group had a worse OS compared with the low-risk group. The nomogram based on this model shows better prediction performance. The four-gene panel was still good predictors for OS in LUAD patients with TP53 and KRAS mutations. The four genes may be significantly related to the metabolism of genetic material, especially in the regulation of cell cycle pathway. Conclusion: Our study proposed a novel four-gene panel to predict the OS of LUAD, which may contribute to predicting prognosis accurately and making the clinical decisions of individual therapy for LUAD patients.