bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluating Effectiveness of Stimulation Treatment in Karachaganak Multistage Wells
Authors: Kushkumbayeva Gulmira , Zhumabayev Bolat , Gabdullin Daniyar , Burmantsev Ruslan , Adeleke Justus , Saada Tamer , Burrafato Giovanni , Brancolini Alberto 
Published: October 2018

Abstract
The first objective of this paper is to present some correlations between formation acid response with stimulation type, reservoir quality, post stimulation injectivity index, productivity index and production logging flow contribution from each of the stimulated zones of wells in the Karachaganak field. The second objective is to provide recommendations on acid stimulation based on geological settings, lithology, petrophysical properties and presence of natural fractures in order to optimize hydrocarbon recovery in carbonate reservoirs in a cost effective manner.
An evaluation of the technical assessment of multistage stimulation based on lithology, porosity, natural fractures, stimulation type, injectivity and the production logging data flow contribution of each zone is the methodology for acid effectiveness measurement. The zonal injectivity of each well generated in Excel describes the pre- and post-stimulation injectivity relative to the stimulation type (acid wash, high rate matrix and acid fracturing). Utilization of Python's matlab to read Excel injectivity analyses data for all the wells further enabled generation of plots for multivariable analyses of the impact of various parameters on productivity. This paper presents the cost effectiveness of stimulation treatment types.
The observation and results of stimulation carried out in many wells shows that porosity, as a petrophysical parameter is not the sole driver of stimulation effectiveness as low porosity zones particularly limestone dominated can have enhanced natural permeability (vugs, fractures) and may have a chance to flow. The high rate matrix technique especially in high dolomitic formation showed better performance when compared to acid frac in the same formation type. Good porosity lithology zones with evidence of natural fractures and/or those that experienced significant mud losses treated with gentle acid wash or high rate matrix showed great productivity with production logging results. The zones close to the toe and the oil water contact treated with acid wash gave good productivity compared to acid frac that tend to intersect natural fractures and connect to the underlying aquifer.
The holistic approach to stimulation results evaluation in carbonate reservoirs is new and will add to the body of knowledge on the most optimal and cost effective acid stimulation type for carbonate reservoirs.
Acid Fracturing Depleted Carbonates Improving Very Low Reservoir Quality Inside Slim Horizontal Open Hole
Authors: Abd El Baky Amr , Al-Shuaibi Nawaf , Alboueshi Alaa Eldine , Elmofti Mohamed , Elafify Ebrahim , Alkhaldy Meshal , Allam Ahmed , Eid Walid , Ashkanani Anfal 
Published: October 2018

Abstract
The execution of pinpointed multi-stage acid fracturing inside 4-1/8-in. slim horizontal open hole sections is discussed. For the first time in Kuwait, pinpoint stimulation of 16 frac stages across a total 4,666 ft open hole while commingling three reservoir sections in very low reservoir quality carbonate rock was performed. Pumping rates were optimized while managing differential sticking hazards in the implementation of this frac procedure. Electric submersible pump completion deployment and well testing enhanced production by more than 100% over the anticipated rate.
Stimulation parameters were optimized with 2-7/8-in. tubing as the frac string for greater reservoir penetration and productivity enhancement. Differential sticking was addressed by removing drilling filter cake prior to the frac job. Possible risks were evaluated, and mitigation plans were implemented which resulted in the successful application of multi-stage acid fracturing across the open hole.
Real-Time Simulation of Deep Azimuthal Resistivity Tool in 2D Fault Model Using Neural Networks
Authors: Kushnir Dmitry , Velker Nikolay , Bondarenko Alexey , Dyatlov Gleb , Dashevsky Yuliy 
Published: October 2018

Abstract
In most cases, interpretation of resistivity measurements is performed using 1D multilayered formation models that are used to fit data locally in real-time applications. While drilling high-angle or horizontal wells, more complex scenarios may occur, such as faults, pinch-outs, or unconformities. In these cases, resistivity logging data inversion should be performed using at least a 2D model, which is a more complex computational problem. This paper presents a neural networks approach for solving this problem exemplified by the application of a deep azimuthal resistivity tool for geosteering in the vicinity of a tectonic fault.
The tool operational frequencies of 400 kHz and 2 MHz produce eight measurements with a coaxial arrangement of transmitters and receivers, and two azimuthally sensitive measurements with axial transmitters and transverse receivers.
This paper considers a 2D model of a tectonic fault composed of three parallel layers on the one side of a displacement plane and the same three layers on the other side dislocated at a certain distance along the displacement plane. The model is described with nine independent parameters. The artificial neural networks (ANNs) were designed and trained to calculate the tool signals based on the model parameters. The training was carried out using a synthetic database of 4·105 elements containing the model parameters and corresponding tool signals. The database was calculated using distributed computations with in-house Pie2D software that used the boundary integral equation technique.
To estimate the accuracy of the ANNs designed, the signals calculated with the networks were compared against the exact values obtained with Pie2D for an independent sample of 1.8·104 points. The comparison gave a good match for all 10 measurements, with the relative error comprising less than one standard tool measurement error for most points of the sample. Computation with the ANN required a few microseconds to calculate one signal, while the algorithm based on boundary integral equations required several minutes. The obtained acceleration of ~106 indicates many opportunities for modeling and inversion of logging-while-drilling data.
New Exploration Frontiers from Xinjiang, Northwest China----Low-Rank Coal Reservoir Character and CBM Exploration Potential in Junggar Basin
Authors: Yu Yuanjiang , Wang Yonghua , Liu Damen 
Published: October 2018

Abstract
Low-rank coalbed methane (CBM) in Junggar Basin has recently become a new exploration frontier across Xinjiang, Northwest China. The low-rank coal reservoir mainly develops in Badaowan Fm. (J1b) and Xishanyao Fm. (J2x) coal measures, especially featuring stable distribution, great thickness and moderate burial depth, which is favorable of CBM accumulation.
The pores of Jurassic coalbed reservoirs are mainly small-micro (&lt;100nm) and large ones, among which the large and medium sizes account for a high proportion; and macroscopic and microscopic fissures are well developed in the reservoirs, leading to a great variation of the permeability. The shallow coal reservoirs are mostly undersaturated, and the gas saturation tends to increase toward the deep coalbed. The low rank coalbed reservoirs have strong ability to adsorb and accumulate CBM. In terms of horizon, the J2x coalbed reservoir has a stronger methane adsorption and storage capacity than J1b and better physical properties, making CMB recovery easier. In terms of region, the coalbed reservoirs in Changji--Urumqi--Fukang areas in the southern margin of the basin, Cainan--Balikun coalmine regions in the eastern part as well as the hinterland of the basin reach the level with methane-rich to extremely methane-rich coal beds and have strong ability to adsorb and store CBM.
Coalbeds of the basin have gas shows in common and good gas-bearing property. The low rank CBM takes a large proportion of the CBM resource, with huge potential. In light of Langmuir’s volume, the gas provinces are classified into four types: poor CBM zone (&lt;8m3/t), CBM-bearing zone (8-15m3/t), relatively rich CBM zone (15-20m3/t), rich CBM zone (&gt;20m3/t). The relatively rich CBM zones cover Wellblock Qing 1 to Qi 8, Changji--Urumqi--Fukang area and slope belt of northwest margin—basin hinterland; while the rich CBM zones include eastern Junggar basin and Balikun coalmine region. These areas together with the adjacent thick coal region and hinterland have a great potential in deep CBM development.
Since 2005, Changji Liuhuanggou block in the south Junggar basin has been selected as PSC block for venture exploration, and a series of CBM projects and researches have been carried out successively. Recently the CBM extraction from Dahuangshan coal mine in the south Junggar, industrial gas flow from the exploration well in the western Baiyanghe of Fukang block, and deep CBM exploration breakthrough in Baijiahai of the east Junggar demonstrated good progress in exploration and proved the huge potential of low rank CBM development.
Influence of Hydrogen Sulfide on Proppants Performance
Authors: Gorshkov Nikolay , Abdrazakov Dmitriy , Nesterova Svetlana , Bolyspayev Nurlan 
Published: October 2018

Abstract
Fast production decline is a well-known negative phenomenon after some hydraulic fracturing jobs. Reasonably, it is usually attributed to the fracture and reservoir parameters. One of the potential fracture parameters that might contribute to the production decline is conductivity of the proppant pack; this conductivity can be damaged by poor proppant condition. In this study, we investigate the influence of hydrogen sulfide (H2S) on the proppant conditions and performance.
The experimental study assessed the influence of H2S on proppant properties. The study analyzed not only the crush strength and sieve size alterations after exposure of proppant to high H2S content, but also the changes in proppant pack conductivity. Because the proppant pack conductivity is directly related to fluid flow within the fracture, this parameter should be considered as a key parameter for estimation of H2S influence on proppant pack performance.
According to test results, no significant influence of the H2S was revealed for all considered parameters. The proppant pack conductivity change was found to be negligible for the given conditions. Therefore, the influence of H2S on well productivity due to proppant pack conductivity impairment was not proved. The field cases and published examples presented in the current study also did not show evidence of proppant pack conductivity damage by the H2S.
To Find Karachaganak
Authors: Anisimov Leonid 
Published: October 2018

Abstract
The nature of the margins of the Precaspian Basin remains one of the most controversial issues, which at the same time, is crucial for determining the prospects of oil and gas potential. The success of the Karachaganak field discovery in 1979 is still not repeated, which is due to the suboptimal modeling of objects of this kind. A new approach to understanding the conditions of formation of carbonate massifs in the inner part of the depression as a consequence of the gravitational sliding of rocks from the side of the margins is proposed. This approach will allow more productive work on the search for structures of the Karachaganak type.
Markov chain Monte Carlo based on adaptive Metropolis algorithm applied in combined model to deal with the uncertainty of weights of single models
Authors: Xing Zhenxiang , Zhang Han , Ji Yi , Xinglong Gong , Fu Qiang , Li Heng 
Published: October 2018

Abstract
Reliability and validity of model prediction play a decisive role in water resource simulation and prediction. Among many prediction models, the combined model (CM) is widely used because it can combine the prediction results of multiple single models and make full use of the information provided by various methods. CM is an effective method to improve the predictive veracity but the weight of single model estimation is the key to the CM. Previous studies take errors as the objective function to calculate the weight, and the uncertainty of the weight of the individual model cannot be considered comprehensively. In order to consider the uncertainty of the weight and to improve universal applicability of the CM, in this paper, the authors intend the Markov chain Monte Carlo based on adaptive Metropolis algorithm (AM-MCMC) to solve the weight of a single model in the CM, and obtain the probability distribution of the weight and the joint probability density of all the weight. Finally, the optimal weight combination is obtained. In order to test the validity of the established model, the author put it into the prediction of monthly groundwater level. The two single models in the CM are time series analysis model (TSAM) and grey model (GM (1,1)), respectively. The case study showed that the uncertainty characteristic of the weight in the CM can be obtained by AM-MCMC. According to the study results, CM has obtained a least average root mean square error (RMSE) of 0.85, a mean absolute percentage error (MAPE) of 8.61, and a coefficient of determination (R2) value of 0.97 for the studied forecast period.
Structural Barriers to Pre-exposure Prophylaxis Use Among Young Sexual Minority Men: The P18 Cohort Study
Authors: Jaiswal Jessica , Griffin Marybec , Singer Stuart N. , Greene Richard E. , Acosta Ingrid Lizette Zambrano , Kaudeyr Saara K. , Kapadia Farzana , Halkitis Perry N. 
Published: October 2018

Background:
Despite decreasing rates of HIV among many populations, HIV-related
health disparities among gay, bisexual and other men who have sex with men persist, with disproportional
percentages of new HIV diagnoses among racial and ethnic minority men. Despite increasing
awareness of HIV pre-exposure prophylaxis (PrEP), PrEP use remains low. In addition to exploring
individual-level factors for this slow uptake, structural drivers of PrEP use must also be
identified in order to maximize the effectiveness of biomedical HIV prevention strategies.

Method:

Using cross-sectional data from an ongoing cohort study of young sexual minority men
(N=492), we examine the extent to which structural-level barriers, including access to health care,
medication logistics, counseling support, and stigma are related to PrEP use.

Results:

While almost all participants indicated awareness of PrEP, only 14% had ever used PrEP.
PrEP use was associated with lower concerns about health care access, particularly paying for PrEP.
Those with greater concerns talking with their provider about their sexual behaviors were less likely
to use PrEP.

Conclusion:
Paying for PrEP and talking to one’s provider about sexual behaviors are concerns for
young sexual minority men. In particular, stigma from healthcare providers poses a significant barrier
to PrEP use in this population. Providers need not only to increase their own awareness of and
advocacy for PrEP as an effective risk-management strategy for HIV prevention, but also must work
to create open and non-judgmental spaces in which patients can discuss sexual behaviors without
the fear of stigma.
Searching for Potential Novel BCR-ABL Tyrosine Kinase Inhibitors Through G-QSAR and Docking Studies of Some Novel 2-Phenazinamine Derivatives
Authors: Kale Mayura , Sonwane Gajanan , Choudhari Yogesh 
Published: October 2018

Background:The computational studies on 2-phenazinamines with their protein targets have been carried out to design compounds with potential anticancer activity and selectivity over specific BCR-ABL Tyrosine kinase.Methods:This has been achieved through G-QSAR and molecular docking studies. Computational chemistry was done by using VLife MDS 4.3 and Autodock 4.2. 2D and structures of ligands were drawn by using Chemdraw 2D Ultra 8.0 and were converted into 3D. These were optimized by using semi-empirical method called MOPAC. The protein structure was downloaded as PDB file from RCSC protein data bank. PYMOL was used for studying the binding interactions. The G-QSAR models generated were found to possess training (r2=0.8074), cross-validation (q2=0.6521), and external validation (pred_r2=0.5892) which proved their statistical significance. Accordingly, the newly designed series of 2-phenazinamines viz., 3-chloro-4-aryl-1-(phenazin-7-yl) azetidin-2-ones (4a-4e) were subjected to wet lab synthesis. Alternatively, docking studies were also conducted which showed binding interactions of some derivatives with > 30% higher binding energy values than the standard anticancer drug imatinib. The lower energy values obtained for these derivatives indicate energetically favorable interaction with protein binding site as compared to standard imatinib.Results:G-QSAR and molecular docking studies predicted better anticancer activity for the synthesized azitidine derivatives of 2-phenazinamines (4a-4e) as compared to standard drug.Conclusion:It is therefore surmised that the molecular manipulations at appropriate sites of these derivatives suggested by structure activity relationship data will prove to be beneficial in raising anticancer potential.
Burkholderia Cepacia Complex Causing Pneumonia in an Immunocompetent Non-Cystic Fibrosis Patient: Case Report and Review of Literature
Authors: Datta Priya , Gupta Menal , Kumar Mani B. , Gupta Varsha , Chander Jagdish 
Published: October 2018

Background:Burkholderia cepacia complex is widespread in the environment and has been recognized as a cause of opportunistic pulmonary infections, particularly in patients with Cystic Fibrosis (CF). The natural ecology of the bacteria as part of plant growth-promoting rhizosphere provides stark contrast to its infectious potential. Its preponderance as a nosocomial pathogen may be due to its ability to survive in antiseptic solutions, contaminate equipments and intrinsic antimicrobial resistance.Case:An elderly, diabetic male was evaluated for hemoptysis, fever and cough. Chest computed tomography showed a thick walled cavity in the left lung and hilar lymphadenopathy. Sputum examination showed Gram negative bacilli and no acid fast bacilli. Sputum culture yielded growth of non-fermentative Gram negative bacilli on two occasions, but blood culture was sterile. The isolate was identified as B. cepacia by Matrix Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS). The patient’s general condition remained poor and in spite of initiation of antibiotics, the patient expired after an episode of massive hemoptysis.Conclusion:This report raises concerns regarding the spread and severity of B. cepacia infection in non-compromised patients in the community and the need to suspect and identify it. Since the organism is inherently resistant to antipseudomonal penicillins, aminoglycosides and polymyxin B, differentiation from Pseudomonas spp. and determining antimicrobial susceptibility is paramount for treatment..
The Pricing and Performance of Supercharged IPOs
Authors: Edwards Alexander , Hutchens Michelle , Rego Sonja Olhoft 
Published: October 2018

ABSTRACT
This study examines a new form of initial public offerings, “supercharged” IPOs, where a firm-organized pre-IPO as a pass-through entity undergoes a series of transactions that steps-up the adjusted tax basis of the IPO firm's assets. This step-up imposes tax liabilities on pre-IPO owners, but also creates significant future tax benefits for the firm; the average anticipated deferred tax asset is $486 million ($13 per share) for our sample of supercharged IPO firms. Pursuant to tax receivable agreements, supercharged IPO firms pay a large portion of these tax benefits to pre-IPO owners as they are realized in the future. Future firm performance must be sufficiently strong for the IPO firm and the pre-IPO owners to realize the future tax benefits created by the supercharged transaction structure. We hypothesize and provide evidence of higher IPO offer prices and stronger future performance for supercharged IPO firms relative to traditional IPO firms.
JEL Classifications: G14; G32; G34; H25.
What's in a Name? Initial Evidence of U.S. Audit Partner Identification Using Difference-in-Differences Analyses
Authors: Cunningham Lauren M. , Li Chan , Stein Sarah E. , Wright Nicole S. 
Published: October 2018

ABSTRACT
We investigate changes in the quality and cost of audit services surrounding PCAOB Rule 3211, which requires disclosure of audit partner names in Form AP. To isolate changes due to Rule 3211 from other confounding factors, we use difference-in-differences analyses with separate control groups, including a group of companies that disclosed partner identities prior to Rule 3211. Our study also incorporates several measures from prior literature to proxy for various dimensions of audit quality. Evidence from the difference-in-differences analyses reveals that any immediate impact of Rule 3211 on audit quality or fees is limited to specific dimensions of audit quality, specific control groups, and/or specific company characteristics. We reach this conclusion after considering alternative research designs and evaluating confidence intervals for statistically insignificant coefficients. We caution that our findings only provide initial evidence and further research is necessary to evaluate other potential impacts of Rule 3211.
Struktur Komunitas Karang Jamur (Fungiidae) di Perairan Pulau Haruku, Kabupaten Maluku Tengah
Authors: Souhoka Jemmy 
Published: October 2018

Karang jamur (Fungiidae) termasuk salah satu suku karang keras (Scleractinian) yang hidup soliter dan bebas tidak melekat pada substrat dasar perairan. Penelitian tentang jenis karang jamur dan struktur komunitasnya belum banyak terungkap, salah satunya di perairan Pulau Haruku, Kabupaten Maluku Tengah, Provinsi Maluku. Tujuan penelitian ini mendapatkan data komposisi jenis dan struktur komunitas karang jamur di perairan Pulau Haruku. Penelitian struktur komunitas karang jamur telah dilakukan pada bulan April 2014 di perairan Pulau Haruku yang bertempat di 4 lokasi yaitu Desa Hulaliu (Stasiun 1), Desa Aboru (Stasiun 2), Desa Haruku (Stasiun 3) dan Desa Kailolo (Stasiun 4). Metode penelitian yang digunakan yaitu transek sabuk dengan luas transek 140m² (2x70m). Hasil analisis ditemukan 12 jenis karang jamur yang mewakili 6 genus. Karang jamur jenis Fungia concinna, Fungia fungites dan Herpolitha limax sangat dominan ditemukan di perairan Pulau Haruku. Nilai indeks keanekaragaman spesies (H) berkisar dari 0,72 – 0,92 dalam kondisi rendah atau tidak stabil. Nilai keseragaman jenis (E) berkisar dari 0,72 – 0,90 yang berarti komunitas labil sampai stabil. Nilai indeks dominansi jenis (D) berkisar dari 0,15 – 0,28 yang berarti dominansi rendah. Kekayaan jenis (d) berkisar dari 4,34 – 6,38. Kepadatan karang jamur untuk tiap stasiun berkisar dari 0,25 (Stasiun 4) – 0,50 individu/m² (Stasiun 1). Perairan pulau Haruku cukup baik bagi pertumbuhan karang jamur.