bluuebunny/crossref_metadata_2025_split huggingface dataset:
Creation of New Multistage Frac Technologies for Implementation in Horizontal Wells in Oil Fields of the Republic of Tatarstan
Authors: Ganiev Bulat , Lutfullin Azat , Muhliev Ilnur , Husainov Ruslan , Garifullin Artur , Postnov Timur , Postnov Anton 
Published: October 2019

Abstract
Today, significant reserves of PJSC TATNEFT are concentrated in the filled-up terrigenous deposits. A feature of these objects is a high zonal heterogeneity, dissection, degraded filtration-capacitive properties, small thickness (no more than 3-4 meters). Effective development of reserves from these facilities is not possible without the use of high-tech methods of stimulation, primarily drilling of horizontal wells with multi-stage hydraulic fracturing (MSHF).
The aim of the work was the search and adaptation of new solutions, among which was the MSHF using "Plug & Perf" technology. The advantages of this technology is that the whole process is performed exclusively using a logging lot and a hydraulic fracturing fleet, which significantly speeds up the process and allows you to work without additional tripping.
This technology allowed the maximum acceleration of multiple fracturing and minimum damaging of the bottomhole zone during the formation davelopment. During the development, the planned values of the flow rate of the fluid were achieved, which made it possible to introduce a small-sized installation into the well. For the further development of the direction of multiple hydraulic fracturing in horizontal wells, development objects and technological solutions have been identified. The experience of using this technology will allow the low-permeability and clayey thin reservoirs to be actively involved in active development, at the same time increasing the efficiency and speed of work on the multi-stage hydraulic fracturing.
Completion Design Optimization for Unconventional Wells Using Large Scale Computational Science
Authors: Cotrell David , Hoeink Tobias , Odusina Elijah , Ghorpade Sachin , Stolyarov Sergey 
Published: October 2019

Abstract
In the current state of the oil and gas industry, unconventional resources are a significant source of the total production output. Unconventional wells remain profitable at various price points, because initial stimulation treatments can be tailored to changing market conditions, reflecting completion costs and (estimated) hydrocarbon prices. The same holds true for re-stimulation of already producing wells. Stimulation treatment "opens" up the subsurface to ultimately allow for better drainage of the reservoir hydrocarbons. The primary stimulation treatment currently in use is hydraulic fracturing, in which the wellbore is broken up into multiple stages, and highly pressurized fluid (oftentimes water) is pumped into each stage of the wellbore. This causes fractures to propagate away from the wellbore, which in turn enhances the local reservoir permeability and allows for economical production. Historically, the number of stages, and clusters per stage, for hydraulic stimulation has been based on wellbore horizontal length (e.g., 200 ft or 400 ft), or much valued previous experience in the same or similar area, as well as other investment considerations. Over time, a strong tendency has developed to place stages and clusters closer together to improve production. However, it is reasonable to assume that there will be a point beyond which adding another stage becomes more expensive than what is gained by increased production revenue from the greater stage count (i.e., less profitable depending on the time of investment). This scenario frames a classic optimization problem which is solved using Monte Carlo methods. Results show that optimal stimulation treatment configurations are robust for many objective functions related to the fracturing process (e.g., propped length and propped height). However, we find that objective functions related to production, production revenue, and profit often provide different optimum treatment configurations, and that those optima shift with respect to the considered timeframe. Because business decisions will ultimately be based on profit decisions over a given time span, we propose utilizing the appropriate objective function together with an integrated modeling approach such as presented here.
Improving the Effectiveness of Multi-Stage Hydraulic Fracturing in Horizontal Wells by Fracture Height Restriction
Authors: Valiullin Albert , Astafyev Vladimir , Osipov Ilya 
Published: October 2019

Summary
The cost-effective development of low-permeability hydrocarbon formations of small thickness requires horizontal wells with multi-stage hydraulic fracturing (MS-Frac). The presence of higher or lower layers that are water-saturated and weak barriers to height growth imposes a restriction on the desirable geometry of the fracture to prevent a breakthrough into a flooded interval. Combining several methods of fracture height restriction and controlling such height can improve the efficiency of multi-stage hydraulic fracturing. The first technology to control the effective pressure was based on changing fracturing fluid rheology and resulted in a decrease in the net pressure and the fracture height. The main treatment buffer utilized a hybrid fluid design. The second technology used to limit the height of the fracture was based on creating artificial barriers inside the fracture that restrict height growth. In this case, a special mixture of proppants was pumped before the primary proppant-laden fracturing main stage. The construction of a horizontal well with a multizone completion implies the possibility of carrying out small volume multistage fracturing to prevent breakthrough into a water-saturated interval, creating an effective drainage zone. For the first time in the given field, MS-Frac was performed using combined technologies and techniques for fracture height growth restriction. The operations demonstrated successful results of horizontal multizone well treatments, where the rheology and fluid rate control methods were used to restrict the fracture geometry growth, and proppant slugs were used to create artificial barriers to arrest the fracture height growth.
The Development of Chemical Stimulation Method Trends in Sandstone Reservoirs
Authors: Shcherbakov Georgii , Yakovlev Andrey , Groman Andrey , Maltcev Andrei 
Published: October 2019

Abstract
The article describes the main ideas of the integrated approach to the use of matrix-stimulation methods in the oilfields with sandstone reservoirs. LLC Gazpromneft scientific and technology center as the basis of the project "Optimal matrix stimulation methods" undertook the joint study. The main tasks of the project are related to the development of software tools such as: the tool for diagnosis of formation damage type in near-wellbore zone, the tool for selecting the optimal technology of near-wellbore treatment, the tool for matrix stimulation design with the possibility of it’s optimization.
The Opportunity of Drilled Solids Use in Lost Circulation Control
Authors: Salmina Tatiana , Shabzova Svetlana , Koval Maxim , Bogatkin Sergey 
Published: October 2019

Abstract
The design work contains development of the technology of circulation loss control during oil and gas wells drilling. Circulation loss control experience suggests that one of effective loss control methods is loss profiles plugging using inwash of fillers (shredded cellophane, cordage fiber, laminar elastic filler, etc.) In order to exclude the use of artificial fillers, it is proposed to use the drilled rock extracted from this well as a filler at the well drilling sites The special feature of the work is the use of travelling unit, which is installed on general platform and includes all required equipment to provide drilled cuttings injection into a well: slurry preparation block (screen shaker, breaking machine, mixing vessel, slurry storage tank) and slurry injection block (piston pump). Before reinjection drilled solids are treated to the parameters, which can provide proper plugging of circulation loss channels (size and shape, chemical inactivity). The approach can decrease the volume of waste production during well construction process, exclude the use of artificial fillers and provide circulation loss control, which would lead to the decrease of ecological load. The applicability, advantages and disadvantages of the technology have been considered, risks analysis has been implemented and the opportunity of drilled solids use in circulation loss control has been thoroughly esteemed in terms of ecology and legislation as an example of AO Samaraneftegaz, the subsidiary of Rosneft.
Low formation pressure, water content, HFT high volumes, sufficient drainage volumes of Rosneft subsidiaries reservoirs – all the above leads to high risks of mud circulation loss during well drilling.
Annual circulation loss control time in oil and gas industry is equal to hundreds of thousands hours. Oil and gas wells construction consumes hundreds of thousands tons of casing strings and cement, millions m3 of drilling mud and chemicals.
Numerical Simulation of Hydrocarbon Mixtures Mass Transfer Processes and Flow in a Reservoir Rock
Authors: Grushnikov Ilya 
Published: October 2019

Abstract
Currently, a number of software products (PVTSim, WinProp CMG, Aspen HYSYS, etc.) are used in the oil and gas industry, simulating the interfacial mass exchange in natural oils, gas condensate mixtures, etc. Existing software products use the vapor-liquid equilibrium calculation methods (flash-calculations) based on various cubic equations of state for the hydrocarbon mixtures. Peng–Robinson and Soave–Redlich–Kwong equations of state are primarily used in these products. Within work (1), the author of current work created a software package in the Python language that can carry out vapor-liquid equilibrium numerical simulations for hydrocarbon mixtures (the paraffin series was considered) using three different cubic equations of state: Peng–Robinson, Soave–Redlich–Kwong and Brusilovskiy. The development of this software package allowed comparison the vapor-liquid equilibrium parameters for hydrocarbon mixtures calculated using these three equations of state.
The vapor-liquid equilibrium calculation for multicomponent hydrocarbon systems is also carried out in the numerical simulation of physicochemical processes in hydrocarbon deposits (simulators Eclipse 300, CMG GEM, etc.). Such calculations are important when the project to develop hydrocarbon deposits involves the injection of multicomponent gas mixtures ("fat" gas, air, etc.) in order to increase oil recovery. Here, using the created software package, we discuss how each of the three equations of state impact numerical simulation results of mass transfer processes between liquid and gas phases under fixed thermobaric conditions. The calculations help analyze how the choice of equation impacts simulation's results when extracting hydrocarbons.
The result of this work was the development of a software package for calculating the PVT parameters for multicomponent hydrocarbon systems in a compositional model based on the cubic equation of state (Peng–Robinson and Soave–Redlich–Kwong). The thermodynamic characteristics, such as density, viscosity and phase component composition, were calculated based on setting the total component composition, equation of state, pressure and temperature. After that, the results of the developed software package were compared with the results obtained using the popular software products for calculating the PVT properties for multicomponent hydrocarbon systems.
Improvement of Effectiveness of Hydraulic Fracturing in Carbonate Sediments P1ar+k of the Pashninskoe Field of the Komi Republic
Authors: Rakitin Evgeniy , Ziganshin Renat , Novokreshchennykh Dmitriy 
Published: October 2019

Summary
The article describes the problem of low efficiency of acid and proppant hydraulic fracturing (HFT) using standard technology in conditions of closely spaced bottom waters of the low-permeable carbonate reservoir P1ar+k of the Pashninskoe field. The hydraulic fracturing technology has been optimized taking into account the geological and physical characteristics (GPC) of the reservoir under consideration and the main complicating factors in the implementation of well interventions (WI) for enhanced oil recovery (EOR). Optimized hydraulic fracturing technology showed high efficiency during testing. Well operation was monitored, according to the results of which the technology was transferred to the industrial category. The results of its replication are also presented. The average specific incremental oil rate from hydraulic fracturing according to the optimized technology was 0.68 tons/day/m, the oil production rate in 2018 increased by 9.4%.
Impact of toothpaste on oral health-related quality of life in people with dentine hypersensitivity
Authors: Mason Stephen , Burnett Gary R. , Patel Nisha , Patil Avinash , Maclure Robert 
Published: October 2019

Abstract
Abstract
Background: Dentine hypersensitivity can impact functional status and everyday activities such as eating and talking. This study aimed to assess changes in oral health-related quality of life measures in individuals with dentine hypersensitivity following long-term use (24 weeks) of a commercially available toothpaste marketed for dentine hypersensitivity relief.
Methods: This study was conducted across two sites and enrolled 75 adults with ≥2 non-adjacent sensitive teeth. Participants were assigned to twice-daily brushing with toothpaste containing 0.454% w/w stannous fluoride (1100 ppm fluoride). Every 4 weeks, participant-reported outcomes were assessed using the Dentine Hypersensitivity Experience Questionnaire (DHEQ), a condition specific oral health-related quality of life scale that has five domains and includes questions on social and emotional impact, restrictions, adaptations and effect on life overall. Responses to a clinically applied evaporative (air) stimulus were assessed using the examiner-observed Schiff sensitivity scale and Labelled Magnitude Scales (LMS), which included dentine hypersensitivity-specific descriptors of intensity, duration, tolerability and descriptive qualities of the participant’s response.
Results: Participant-reported outcomes demonstrated reduction of the impact of dentine hypersensitivity over time on health-related quality of life, as measured by the DHEQ. This reached statistical significance from Week 8 onwards (p<0.0001 versus baseline) for the Total DHEQ score, with scores continually decreasing at each timepoint. Most domain scores followed a similar pattern. Statistically significant reductions were also detected for the examiner-observed Schiff Sensitivity Scale scores at all timepoints (including at 4 weeks) (p<0.05), which were mirrored by LMS responses. The toothpaste was generally well-tolerated.
Conclusions: These results show that long-term use of a sensitivity toothpaste containing 0.454% w/w stannous fluoride has a beneficial, ongoing, impact on the oral health-related quality of life of people with dentine hypersensitivity.
Assessment of weight and height of patients with primary immunodeficiency disorders and group of children with recurrent respiratory tract infections.
Authors: Pieniawska-Śmiech Karolina , Bar Kamil , Babicki Mateusz , Śmiech Karol , Lewandowicz-Uszyńska Aleksandra 
Published: October 2019

Abstract
Background Primary immunodeficiences (PIDs) are a group of chronic, serious disorders in which the immune response is insufficient. In consequence, it leads to an increased susceptibility to infections. Up to date, there are about 300 different disorders classified in that group. There are also patients suffering from recurrent respiratory tract infections (RRTI), however that group doesn't present any abnormalities in terms of conducted immunological tests. Many factors, including medical, can have an impact on physical development of a child. Data such as birth weight and length, also weight, height, BMI during admission to the hospital were collected from 207 patients' medical histories from their hospitalization at Clinical Immunology and Paediatrics ward of J.Gromkowski Hospital in Wrocław. Investigated groups included patients with PIDs, RRTI and a control group of healthy children. Our purpose was to evaluate the physical growth of children with PID and children with RRTI by assessment of their height and weight. All of parameters were evaluated using centile charts suitable best for the Polish population. Results The lowest mean birth weight and height was found among the PIDs patients group. Children with PIDs during hospitalization had statistically relevant lower mean weight than the control group and almost 20% of them had their height situated below 3rd percentile. No statistically relevant differences have been found between them and RRTI group. The statistically significant difference was between the nutritional status of PID patients and the control group. Conclusions There is a higher percentage of PID patients with physical growth abnormalities in comparison to healthy children. Our findings indicate a need for further investigation of immune system irregularities and their influence on physical growth of children.
Use of patients’ unsolicited correspondence to a family doctor to describe and understand valued components of a doctor-patient relationship: A Hermeneutics approach
Authors: Yaffe Mark J. , Hovey Richard B. , Rodriguez Charo 
Published: October 2019

Abstract
Background Communication and behavior within doctor - patient encounters have been examined using varied techniques; however the nature of unsolicited writings from patients to their family doctors has rarely been reported. This paper therefore aimed to explore the content of, and motivation for, such correspondence. Methods 107 writings to one family physician about care provided during a four decade period were considered. Univariate analyses were used to identify features of patients or family members who wrote personalized notes to the doctor, when, and in what fashion. A hermeneutic approach helped look at the content of the notes, the specific words or sentiments used to describe encounters or care received, and possible motivations for writing. Iterative review of words or phrases generated themes which summarized appreciated physician or relational attributes, as well as motivations for writing. Results Notes were mostly handwritten, predominantly by women, and frequently coinciding with holidays and life span events. Appreciated doctor characteristics and behaviors were (1) quality care; and physician (2) competence; (3) physical presence; (4) positive personal traits; (5) provision of emotional support; and (6) spiritual impact. Motivations for writing were grouped as desire to (1) express appreciation for an established relationship; (2) acknowledge value / benefit experienced from continuity of care; (3) seek catharsis, emotional relief or closure; (4) reflect on termination of care; (5) validate care that incorporates both Hippocratic tradition and Asklepian healing ; and (6) share personal reflection, experience, or impact. Conclusions Unsolicited writings provide personalized links from patients to physicians, expressing thoughts perhaps difficult to share face to face. They offer potential as teaching tools about the content of doctor-patient relationships; for example, the writers studied expressed appreciation for quality continuity care that was competent, considerate, and supportive of emotional and spiritual needs.
Determinants Of Neonatal Mortality In The Largest International Border Of Brazil: A Case-Control Study
Authors: de Souza Suzana , Duim Etienne Larissa , Nampo Fernando Kenji 
Published: October 2019

Abstract
BACKGROUND: Foz do Iguassu is a Brazilian municipality located in the most populous international border of the country and provides medical care to foreigners. Neonatal mortality in the city is higher than Brazil’s average and corresponds to 61% of all deaths in children under five. The current study aimed to identify the determinants of neonatal mortality in Foz do Iguassu. METHODS: In this case-control study, we analyzed all neonatal deaths occurred in Foz do Iguassu from 2012 to 2016. Birth and mortality data were extracted from two national governmental databases (SINASC and SIM). We extracted data on (i) maternal sociodemographic characteristics, (ii) pregnancy care, and (iii) newborn characteristics. Multiple logistic regression with the conceptual framework was applied to examine the factors associated with neonatal mortality. RESULTS : Most of the deaths occurred in the early neonatal period (65.9%). The factors associated with neonatal death were fetal congenital anomaly (OR 22.49; CI 95% 7.44-67.95; p = <0.001); low birth weight (OR 17.15; CI 95% 8.56-34.37; p = <0.001), first minute Apgar score under 7 (OR 15.60; CI 95% 8.23- 29.67; p = <0.001); zero to 3 prenatal appointments (OR 3.34; CI 95% 1.28-8.73; p = 0.014) and prematurity (OR 3.60; CI 95% 1.87‑7.11; p = <0.001). CONCLUSION : The high rate of neonatal death in Foz do Iguassu is strongly associated with newborn characteristics and not associated with maternal sociodemographic characteristics. Thus, the health services in the Brazilian side of this international borders should be aware of the quality of the prenatal care and childbirth attention provided.
Risk factors for peritonitis in patients on continuous ambulatory peritoneal dialysis who undergo colonoscopy: A retrospective multicentre study
Authors: Gweon Tae-Geun , Jung Sung Hoon , Kim Sang Woo , Lee Kang-Moon , Cheung Dae Young , Lee Bo-In , Choi Hwang 
Published: October 2019

Abstract
Background: Colonoscopy is associated with a risk of peritonitis in patients on peritoneal dialysis. However, no study has yet described the risk factors in play. Methods: This was a retrospective multicentre study. The medical records of patients on continuous ambulatory peritoneal dialysis (CAPD) who underwent colonoscopy from January 2003 to December 2012 were analysed. We recorded demographic characteristics, colonoscopic factors, use of prophylactic antibiotics, and development of peritonitis. Colonoscopy-related peritonitis was defined as peritonitis developing within 1 week after colonoscopy. Demographic and clinical characteristics were compared between patients who did and those who did not develop peritonitis. Results: During the study period, 236 patients on CAPD underwent colonoscopy, of whom 9 (3.8%) developed peritonitis. The rates of polypectomy/endoscopic mucosal resection were significantly higher in the peritonitis group than in the no peritonitis group (66.7 vs. 23.4%, p=0.009). Prophylactic antibiotics were prescribed before colonoscopy in 65 patients; none developed peritonitis. No patient who developed peritonitis received prophylactic antibiotics (p=0.067). Conclusions: Advanced procedures including polypectomy or endoscopic mucosal resection increase colonoscopy-related peritonitis in patients on CAPD. Randomized controlled trials to investigate whether prophylactic antibiotics are needed to prevent peritonitis in all CAPD patients are warranted.