bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Multi-Stage Hydraulic Fractures on Performance of Naturally Fractured Tight Oil Reservoirs with Bottom-Water
Authors: Prasun Samir , Ghalambor Ali 
Published: January 2018

Abstract
Water coning is a major concern in any oil reservoirs with bottom-water. Stimulation techniques such as multi-stage hydraulic fracturing in a horizontal well can accelerate water coning, but uncertainty prevails over the increased recovery under bottom-water support. This paper studies the effect of hydraulic fracture (HF) design properties combined with the matrix and natural fractures properties in tight reservoirs on water-cut and recovery. Ultimately, the results can be applied in deciding the feasibility and design parameters of multi-stage hydraulic fracturing in these reservoirs.
The paper presents a 3-D Cartesian simulation model, which is run for different fracture half-length, fracture height, HF conductivity, natural fractures permeability and matrix permeability, to represent wide variety of hydraulically fractured reservoir systems. Dual porosity-dual permeability (DPDP) model is used to simulate natural fractures inside water-wet reservoir matrix. In a constant pressure bottom-water reservoirs, where the reservoir pressure remains more or less constant and so there is a minimal change in effective stresses with production time, any effect of these stresses on the variation of fracture conductivity or productivity can be ignored.
Results show that although there is a severe water-cut problem associated with hydraulic fracturing a tight oil reservoir with bottom-water, recovery increase is much higher than that without bottom-water, demonstrating the viability of the project. Based on the simulation results on the sensitivity of HF conductivity on water-cut and recovery, lower HF conductivity with smaller fracture width should be preferred which would further reduce the cost associated with the proppants required. Higher matrix permeability enhances the ultimate recovery, whereas tighter zones brings more water-cut problem. Further, studies showed that HF half-length should not be too low to result in low recovery (at10 years) or should not be too high to give rise to low ultimate recovery. Operators should be concerned about the height of HF, as they should not allow it to propagate beyond the upper oil-zone either to transition-zone or water-zone that can severely mitigate the recovery rate as well as ultimate recovery with severe water-cut problems.
This study which is based on sensitivity analysis, can be used to design the fracture half-length, height, and conductivity in bottom-water-tight reservoirs. The study can provide a boost to operators who are reluctant to hydraulically fracture a bottom-water reservoirs.
Laboratory Investigation of Zinc and Lead Sulphide Inhibition
Authors: Al-Harbi Bader G. , Graham Alexander J. , Sorbie Ken S. 
Published: January 2018

Abstract
The formation of zinc sulphide (ZnS) and/or lead sulphide (PbS) has been a persistent problem, particularly in high temperature high pressure HT/HP fields. ZnS and PbS deposition can pose safety hazards and have serious economic consequences including reduction in well productivity and may require the implementation of an effective scale mitigation and removal strategy. HT/HP fields are prone to critical changes in temperature and pressure and, in addition, they usually have high salinity brines; indeed they are often referred to as HP/HT/HS systems. When these factors (pressue/temperature/salinity) vary together, they tend to trigger the formation of inorganic scales including sulphides. Apart from the role of temperature and salinity in scale formation, these (HT/HS) conditions often negatively impact scale inhibitor performance due to chemical degradation or incompatibility.
The objective of this study was to investigate ZnS and PbS formation (as single or combined scales) and inhibition over a range of parameters including pH, temperature, salinity, time and initial Zn, Pb and H2S concentrations. Polymeric and phosphonate scale inhibitors (SIs) were tested using static scale formation experiments, with samples being analysed by inductively coupled plasma (ICP) analysis, Environmental Scanning Electron Microscopy (ESEM), pH and particle size distribution measurements.
Of the seven scale inhibitors tested, only two demonstrated inhibitory capacity at active concentrations of 100 ppm or below. SI-2, a high-molecular weight polymer, was remarkably effective in preventing both zinc and lead sulphide deposition regardless of the final supernatant pH. SI-3 showed more limited efficacy compared with SI-2 with its highest inhibition being achieved at low pH values.This information is important to consider when designing scale inhibitor treatments; as carbon dioxide liberates from produced water due to decreasing pressureit causes the pH to increase, which may cause a drop in the inhibition efficiency of some scale inhibitors. Increasing the brine salinity had a detrimental impact on the performance of the tested scale inhibitors. Neither SI-2 nor SI-3 were able to prevent PbS deposition by ionic displacement of Zn from ZnS by Pb2+ despite the fact that both scale inhibitors were effective against PbS under the same conditions using the conventional scale inhibition experiments.
The particle size distribution of the partially inhibited ZnS and PbS particulates was found to be dependent on the type and concentration of the scale inhibitor, the final pH and salinity. The difference in particle size could have significant effects on in-line filter blocking tests and produced water quality issues.
An Improved Ball Sealer Model for Well Stimulation
Authors: Tan Xuehao , Weng Xiaowei , Ahmed Tausif Khizar , Bukovac Tomislav , Enkababian Philippe 
Published: January 2018

Abstract
Ball sealers are commonly applied in fracturing and acidizing treatments for diverting treatment fluid to the desired zones by plugging perforations. It has proven that injecting ball sealers is a low-cost and efficient method for diversion. To predict the effectiveness of ball sealers, an improved ball sealer seating model is developed by introducing the maximum seating efficiency and random functions to capture the stochastic nature of ball-sealer plugging. The new model can predict ball sealer performance with different ball densities in vertical, deviated and horizontal wells.
The traditional ball sealer model was originally designed for vertical wells, where ball sealers with different densities have similar behavior. However, for deviated and horizontal wells, the seating of buoyant and dense balls is more complicated. Buoyant balls tend to plug the perforations at the top of wellbore, and dense balls tend to plug the perforations at the bottom of wellbore. Thus, the traditional ball sealer model cannot be applied in these wells. A maximum seating efficiency for each ball is introduced in the new model, which is obtained by correlations based on experimental results. To describe the stochastic nature of ball sealer seating on perforations, a random number is assigned to each ball sealer, and a range is assigned to each perforation based on the ratio between flow rates through the perforations and flow rate in the wellbore.
With the improved model, it can predict seating efficiency of ball sealers for all types of well with buoyant, neutral and dense balls. The results are showing that the seating efficiency of ball sealers predicted by the model can match the experimental results, which validates the model. Based on the simulation results, when ball sealers with mixed densities are pumped into deviated or horizontal wells, the seating efficiency is better than pumping ball sealers with only one density. For vertical wells, the benefit of mixing densities is minimal.
Nanomaterials-Enhanced Hydrocarbon-Based Well Treatment Fluids
Authors: Li Leiming , Ozden Sehmus , Al-Muntasheri Ghaithan A. , Liang Feng 
Published: January 2018

Abstract
The introduction of water-based fracturing fluids to water-sensitive formations may cause formation damages and thereafter lower the production numbers. Due to the advantages such as low formation damage, good proppant suspending and carrying ability, good compatibility with water-sensitive formations, etc., the waterless, hydrocarbon-based fluids are routinely used in fracturing, sand control, coiled tubing cleanout, and other oilfield operations.
To better generate fractures and place proppant, the phosphate esters-based gelled oil fluids have been preferred since they are more robust and cost-effective compared to other types of hydrocarbon-based fluids. Phosphate esters are commonly used with metal crosslinkers such as iron or aluminum compounds to form gelled oil fluids. Since phosphate esters may cause fouling in refinery equipment, the dosage should be reduced to the minimum but without compromising the fluid performance. A number of novel additives have been identified that could maintain or even enhance the rheological properties of the gelled hydrocarbon fluids with reduced usage of the phosphate esters.
When doped with the novel functional nanomaterials, the rheological properties of the gelled hydrocarbon-based fluids were enhanced from room temperature to 250°F or above. The selected nanomaterials could have van der Waals-like forces, thus strengthening the three-dimensional network of the metal-crosslinked phosphate esters in the gelled hydrocarbon fluid. This way, the overall viscosity of the hydrocarbon-based fluid could increase with lower amount of phosphate esters. For example, the addition of 30ppt (pounds per thousand gallons) of additive-A synergistically improved the viscosity of the gelled oil fluid by about 73% compared to the baseline gelled fluid that did not contain the additive. With additive-A at 30ppt, the amount of the phosphate esters in the fluid could be reduced by 25% without affecting the fluid performance. Besides additive-A, other types of functional nanomaterials including additive-B, additive-C, and additive-D were all found to enhance the rheological properties of the gelled hydrocarbon fluids by as much as about 45%.
The novel gelled hydrocarbon fluid formulas were successfully applied with the crude oil from the field, resulting in viscosity boosts up to about six times. Further discussions about the enhancing behaviors and mechanisms of the selected novel additives in the gelled hydrocarbon fluids and the laboratory test results will be presented in detail.
Water resource system vulnerability assessment of the Heihe River Basin based on pressure-state-response (PSR) model under the changing environment
Authors: Men Baohui , Liu Haoyue 
Published: January 2018

Abstract
As one of the most important inland rivers in China, the shortage of water resources and ecological deterioration of the Heihe River has increasingly attracted attention, and it is very significant to undertake the water resources sustainable utilization for its vulnerability assessment in the river basin. Using the pressure-state-response (PSR) model, a vulnerability index of the water resources system was developed and used to carry out a vulnerability assessment on the Heihe River in the current year (2010) and the comparison year (2003). The PSR of water resource vulnerability included 11 indexes, which are domestic water quota of urban residents, rural water quota of urban residents, million yuan GDP water consumption, per capita water consumption, ecological water proportion, drought index, per capita water resources, water modulus, water quality grade, water saving irrigation rate, per capita GDP, respectively. The vulnerability of water resources was evaluated by the attribute recognition model. The results show that water resources in the Heihe River Basin were in a quite vulnerable state in both 2003 and 2010 according to the values of scenario A1 (not vulnerable) and scenario B1 (severely vulnerable). It is urgent to protect and restore the water resources system in the Heihe River Basin.
Correlation between nitrous oxide (N2O) emission and carbon to nitrogen (COD/N) ratio in denitrification process: a mitigation strategy to decrease greenhouse gas emission and cost of operation
Authors: Andalib Mehran , Taher Edris , Donohue Joseph , Ledwell Sam , Andersen Mikkel H. , Sangrey Karla 
Published: January 2018

AbstractThe reliability and accuracy of in-situ ion selective electrode and ultraviolet (NOx) probes have been investigated at four different treatment plants with different operational conditions. This study shows that the mentioned probes tend to compromise their accuracy and trending stability at lower NOx of &lt;1.0 mg N/L, which if used as a measuring variable for PI feedback controller for denitrification (biological reduction of nitrate to nitrogen gas), would cause overfeeding the external carbon source. In-situ Clark-type N2O sensors, recently introduced for industrial scale use (Unisense Environment) could potentially open a new horizon in the automation of biological processes and particularly denitrification. To demonstrate the applicability of such probes for automation, two in-situ N2O probes were used in two treatment plants in parallel with NOx-N probes. The effects of operational conditions such as COD/N ratios and the correlation between NOx and N2O were investigated at those plants. N2O production at non-detect dissolved oxygen concentrations and pH of 7–7.2 were found to be a function of influent nitrogen load or the ratio of COD/NINFLUENT. Finally, using an N2O probe as a proxy sensor for nitrates is proposed as a measured variable in the PI feedback in the automation of the denitrification process with a NOx set point of &lt;1.2 mg N/L).
Kisspeptin and its Effect on Mammalian Spermatogensis
Authors: Feng Tao , Bai Jia H. , Xu Xiao L. , Liu Yan 
Published: January 2018

Background:
Kisspeptin and its receptor, GPR54, are regarded as key regulators of and catalysts for male
puberty onset, and also fundamental gatekeepers of spermatogenesis in mammals. Consequently, the loss function of
kisspeptin or GPR54 leads to a symptom of Hypogonadotropic Hypogonadism (HH) in human and HH accompanied
by lower gonadotrophic hormone levels, smaller testes, impaired spermatogenesis and abnormal sexual maturation in
mice. Besides its well-recognized functions in hypothalamus before and during puberty, accumulating data strongly
support kisspeptin production in testis, and participation in somatic and germ cell development and sperm functions
as well. This review aims to summarize recent findings regarding kisspeptin activity in the testes and sperm function.

Methods:
We undertook a keyword search of peer-reviewed research literature including data from in vivo and
in vitro studies in humans and genetically modified animal models to identify the roles of kisspeptins in male
reproduction.

Results:
A plethora of studies detail the role of kisspeptins and GPR54 in mammalian spermatogenesis in vivo and in
vitro. This review identified recent findings regarding the kisspeptin system in male gonads, and regulation of kisspeptin
in testicular physiology and male reproductive defects and disorders.

Conclusion:
The findings of this review confirm the importance role of kisspeptins in male fertility. Understanding
their biphasic roles in testis may help to consider kisspeptins as potential pharmacological targets for treating human
infertility.
Cross-regulatory Circuit Between AHR and Microbiota
Authors: Ji Jian , Qu Hao 
Published: January 2018

Background:
The gut microbes have a close symbiotic relationship with their host. Interactions between
host and the microbiota affect the nutritional, immunological, and physiological status of the host. The Aryl Hydrocarbon
Receptor (AHR) is a ligand activated transcription factor that mediates the toxicity of xenobiotics. Recently,
the relationship between the gut microbiota and AHR has attracted the attention of many researchers.

Methods:
We undertook a structured search of bibliographic databases for peer-reviewed research literature.

Results:
We found and reviewed 49 peer-reviewed papers dealing with the major aspects related to the crosstalk
between AHR and microbiota. The AHR influences the intestinal microbiota population and mediates host-microbe
homeostasis. Interestingly, the gut microbiota also produces ligands of AHR from bacterial metabolism and thereby
activates the AHR signaling pathway.
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Concusion: This review presents current knowledge of the cross-regulatory circuit between the AHR and intestinal
microbiota. The findings of this review confirm the importance of AHR-microbiota interactions in health and disease.
Anticancer Activity Study of Chromone and Coumarin Hybrids using Electrical Impedance Spectroscopy
Authors: Bouhenna Mustapha M. , Mameri Nabil , Pérez Mónica V. , Talhi Oualid , Bachari Khaldoun , Silva Artur M.S. , Luyten Walter 
Published: January 2018

Aims: Oncology treatments aim at selective toxicity for tumor (compared to normal) cells, and chromone-
coumarin hybrids have shown such activity.

Methods:
In this study, we test a novel series of synthetic chromone and coumarin derivatives (1–9) for cytotoxic
activity against a panel of tumor cell lines (MCF-7, A549, HepG2, HTC-116, B16 and Caco-2) opposed to
non-tumor cells (HEK-293t). Electrical impedance spectroscopy was used to monitor cell viability in real time.

Results:
Compound 8 showed the most potent activity, and it significantly diminished cancer cell proliferation
and viability in different cell lines. It induced apoptosis in a dose-dependent manner, as shown by Western blot
and flow cytometry.

Conclusion:
Electrical impedance spectroscopy appears to be a convenient tool for in vitro cytotoxicity analysis,
which could be useful for identifying drug effects and side effects during early phases of drug discovery and
development.
Faktor-faktor yang mempengaruhi kearifan konselor menurut perspektif calon konselor etnis Jawa
Authors: Herdi Herdi , Kartadinata Sunaryo , Taufiq Agus 
Published: January 2018

Tujuan penelitian ini adalah mengeksplorasi faktor-faktor yang mempengaruhi kearifan konselor menurut perspektif calon konselor etnis Jawa. Penelitian menggunakan metode deskriptif jenis survey. Sampel penelitian berjumlah 270 calon konselor etnis Jawa semester enam dari 11 Program Studi Bimbingan dan Konseling di Indonesia. Sampel penelitian dipilih menggunakan teknik purposive sampling. Pengumpulan data menggunakan angket yaitu Skala Anteseden Kearifan Konselor yang berbentuk skala lima jenjang. Teknik analisis data menggunakan statistik deskriptif dan analisis faktor eksploratoris. Hasil penelitian menunjukkan terdapat enam faktor yang mempengaruhi kearifan konselor menurut perspektif calon konselor etnis Jawa. Faktor-faktor yang dimaksud dinamakan: (1) kepribadian dan kecerdasan, (2) pengalaman, (3) atribut pribadi, agama, dan spiritual; (4) keterampilan metakognitif (berpikir kritis dan mendalam); (5) konteks fasilitatif; dan (6) kepakaran (profesionalitas). THE FACTORS AFFECTING A COUNSELOR’S WISDOM IN THE PERSPECTIVES OF JAVANESE PRE-SERVICE COUNSELORSAbstractThe purpose of this research is to explore the factors affecting a counselor’s wisdom in the perspectives of Javanese pre-service counselors. The research adopted a descriptive method of survey. The sample included 270 of the sixth semester of Javanese pre-service counselors from 11 Guidance and Counseling Study Program in Indonesia. Data were collected using questionnaire, which is Counselor Wisdom Antecedents Scale, in the form of five-level scale. The data were analyzed with descriptive statistics and exploratory factor analysis. The findings show that there are six factors affecting a counselor’s wisdom in the perspectives of Javanese pre-service counselors. The six factors named: (1) personality and intelligence, (2) experience, (3) personal attributes, religiosity, and spirituality, (4) metacognitive skills (critical and in-depth thinking skills), (5) context-facilitative, and (6) expertise (professionality).
Terrestrial and solar magnetism’ influence to diphtheria pandemics
Authors: Gumarova L. , Cornelissen G. 
Published: January 2018

The number of physicochemical factors of the environment is extremely high. The geophysical components of the environment are under the influence of cosmic forces. The sun, the moon, the planets and the stars are connected with the Earth by invisible bonds. Gravitation, radiation, electromagnetic fields and corpuscular ceilings of the Sun and stars are far from a complete list of the cosmic forces acting on the Earth. Changes in the activity of the Sun are reflected in the biosphere directly through photosynthesis of plants, and indirectly through changes in climatic conditions on the Earth, which affects various biological processes. One of the first scientists, who paid attention to the dependence of pandemics with solar cycles, was Alexander Chizhevsky.In this study, we perform a meta-analysis of statistical data on diphtheria, based on the data published by Chizhevsky in the 20th century. We here add for the association of terrestrial and solar magnetism with these infectious diseases that were common in the past, using nonlinear analysis, cosinor-analysis and cross-wavelet coherence. We showed the geographic differences hidden in Chizhevsky’s data on diphtheria. Wavelets of Wolf numbers and of the antipodal geomagnetic index show maxima corresponding to the anticipated ~11.7-year cycle, also seen from the spectra plotted vertically next to the color key. The numbers indicate the period length (in years) corresponding to local maxima in amplitudes; but the color code matters most. The wavelet also reveals the presence of an about 22.1-year component differing from the smaller about 19.7-year peaklet observed for Wolf numbers. Both these peaks are less prominent than the about 29.5-year peak found for diphtheria.
Efficacy of Profilactic and Therapeutic Antibiotic in Congenital Hydrocephalus Shunt Infection
Authors: Imron Akhmad , Wiriadisastra Kahdar 
Published: January 2018

Prophylactic dose antibiotic are indicated in patients having neurosurgical clean operations with implant surgery. The aim of this study is to evaluate the efficacy of prophylactic dose antibiotic in shunt infection. Between 1 October 2009 until 31 September 2011, 102 patients with congenital hydrocephalus who underwent VP shunt surgery. Fifty-one received profilactic antibiotic (ceftriaxone 50-75 mg/kgBW), 30-60 minutes before surgery until 5 days post-operative, and 51 patients received therapeutic antibiotic (ceftriaxone 50-75 mg/kgBW), 30-60 minutes before surgery until 1 days post-operative. All patient were followed for 1-6 months to evaluate shunt infection. Collected data will be statistically analyzed. The study found that the rate of infection is 17,6% (9 patients of 51 patients) who received therapeutic antibiotic, and 17,6% (9 patients of 51 patients) who received profilactic antibiotic.There is not statistically significant between all group in shunt infection (p=1,000). Others risk factors significantly influence shunt infection are enlargement of the head (p=0,002), length of surgery (p=0,00327), time of surgery (p=0,00077) and nutrition status (p=0,01343). The results of this study indicate that profilactic antibiotic effective to prevent shunt infection in congenital hydrocephalus. Others risk factors significantly influence are enlargement of the head, length of surgery, time of surgery and nutrition status. Keywords: antibiotic, prophylactic, infection, VP shunt, congenital hydrocephalus