bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Novel Deepwater Kick Control Strategy for Handling Riser Gas Unloading with Data-Driven Parameter Estimation
Authors: Gu Qifan , Fallah AmirHossein , Gul Sercan , Ashok Pradeepkumar , Chen Dongmei , van Oort Eric , Moore Dennis 
Published: October 2020

Abstract
Non-aqueous drilling fluids used in deepwater drilling operations are conducive to the dissolution of formation gas during wellbore influx events, increasing the risk of gas kicks going unnoticed. This can lead to hazardous riser gas unloading events if kicks are allowed to pass the subsea BOPs and come out of solution at the bubble point at shallow riser depth. One possible solution to handle and even prevent these events is to generate enough backpressure using Managed Pressure Drilling (MPD) with a Rotating Control Device (RCD) to keep the dissolved gas in solution. However, for large kicks, the required backpressure may exceed riser pressure limits.
A novel kick handling procedure using a dilution control strategy (DCS) is proposed here to handle gas influxes and subsequent gas unloading events. The idea behind this DCS is to inject mud into the riser through the boost line while simultaneously slowing down the circulation rate through the drillstring as the dissolved kick passes the open subsea BOPs. The kick will then get diluted and will be distributed across a larger annular space leading to a significantly decreased gas concentration that can be more easily handled by the MPD system with lower backpressure.
The feasibility of the DCS is investigated in this paper using a multi-phase flow model which is validated against experimental data for a gas kick in oil-based mud. Simulation results for a demonstration case show that a kick entering the well at 18,500 ft with 2,250 kg gas can be thoroughly eliminated with a 3:1 dilution ratio (which is the ratio of riser boost rate to drillstring circulation rate) with approximately 620 psi backpressure when using an MPD system. To improve the applicability of the proposed DCS procedure in field practice, a data-driven approach is implemented using simulated data points to provide a fast estimation of the optimum dilution ratio (DR) to control the kick in real-time.
Re Multi Fracturing with Flow Diverter
Authors: Amirov Marat Rimovich , Kuzakhmedov Rifat Maratovich , Boroday Aleksey Aleksandrovich , Kashtanov Ivan Gennadyevich , Yazkov Alexander Victorovich , Solovyev Vladimir Vladimirovich , Butkeev Andrey Sergeevich , Eliseev Petr Ilyich , Bagaev Aleksandr Nikolaevich , Fomin Ivan Sergeevich , Fedorov Georgiy Evgenievich , Bakirov Ruslan Rafailovich , Fomin Mikhail Vladimirovich , Fragachan Francisco E. , Cruz Cristian M. , Omer Mohammed , Brendin Mikhail Vladimirovich , Trofimov Denis Sergeevich 
Published: October 2020

Summary
As of today, there are various methods of repeated multistage fracturing. Mostly, they are associated with the involvement of coil tubing and well workover services. These are assemblies with opening and closing frac sleeves, small-sized packers, twin packers, CT packers… All the methods are extremely costly in economic terms, the full operation cycle takes a long time and is associated with a high risk of hazards.
The above methods have an alternative that is not widely used. An alternative and universal method for the repeated MSF is a mechanical, degradable flow diverter. The diverter is a 2-component powder consisting of 7 and 100 mesh particles that can isolate the required open area in the wellbore.
The diverter has an extensive scope of application: it can be used for MSF in several vertical well zones, for MSF in wells with slotted liner completions, for repeated MSF in wells with sliding frac sleeves both in a blind version and with the use of a CT packer. It can be used for additional stimulation of missed, non-activated sleeves in sliding frac sleeve assemblies, as well as for the restoration of circulation, as temporary casing patches, etc.
The basic technology does not require any services in addition to hydraulic fracturing. It is also important to mention that it is completely soluble downhole, which means that additional expenditures for well completion after its use are not required.
In April 2020, the company performed repeated MSF using this flow diverter as a pilot job. As a result of the MSF, the well flow significantly exceeded the expected design values.
Prior to the MSF with a flow diverter, the well wireline logging was performed to determine the flow profile. After performing 3 fracturing stages, a repeated wireline logging confirmed the formation of new fractures in the new zones not stimulated previously.
By virtue of the fact that in these days the drilling rates have been significantly reduced, an urgent need to increase the flow rate of the existing wells appears. That is why high-quality, rapid and accessible repeated fracturing technology has great prospects and promises to become very popular among operators.
A Decade of Multi-Zone Fracturing Treatments in Russia
Authors: Astafyev Vladimir , Samoilov Mikhail , Fayzullin Ildar , Kuvshinov Igor , Mitin Alexey , Fedorov Georgy , Gaponov Mikhail , Ovchinnikov Kirill , Khusainov Ruslan , Fedorov Evgeny , Lushev Mikhail 
Published: October 2020

Abstract
Multistage hydraulic fracturing (MSHF) has given new impulse to the development of hydraulic fracturing market in Russia. This paper illustrates the evolution of horizontal well multi-zone stimulation methods for the past decade in Russia. Examples of multi-zone treatments using various technologies in different fields are given. Analysis of the work performed shows how the integration of modern drilling, completion, stimulation, control and production methods allowed cost-effective development of hard-to-recover reserves. The development of multi-zone well stimulation brought to the market new horizontal well completion, fracture mapping, production and field development control technologies. The article also evaluates potential development and application of multi-zone technologies.
Multistage Horizontal Wells Refracturing by Means of Abrasive Jet Perforation + Frac Technology
Authors: Shaykamalov Rustam , Gaponov Mikhail , Mukhametshin Marat , Bildanov Vladislav , Katermin Alexey , Bashirov Ildar 
Published: October 2020

Abstract
Since 2015, the technology of multistage fracturing (hereinafter MSHF) in horizontal wells has become widespread in Bashneft-Dobycha's fields. MSHF applies to newly-drilled and side-tracked wells (hereinafter ST wells). To date, more than 100 multifracked wells have been put on stream.
The post-MSHF well productivity decreases over time because of the degrading fracture conductivity and depletion of the reserves in the earlier stimulated zones. The most effective method to restore well productivity is refracturing, which was proven in directional wells.
For refracturing, the assemblies that contain frac sleeves activated by dropping the balls of various diameters are mostly used. For openhole isolation of intervals, annular hydraulic-set packers are normally used, without cementing a horizontal borehole section. The application of these MSHF assemblies makes it difficult to further perform interval-wise refracturing. The challenging factors include multiple open intervals after performing all the frac stages and the tight hole in the sleeve intervals, even if milled. One of the refracturing methods tested in Bashneft-Dobycha's horizontal wells was ‘blind’ fracturing. This is the most easy-to-use method, which is not time-consuming either. The effect of these jobs was low, as the most depleted intervals were refractured.
In 2019, a combined technology of abrasive jet perforation and subsequent refracturing through an abrasive jet perforating tool (abrasive jet perforation + fracturing) was proposed for multifractured horizontal wells. The application of the abrasive jet perforation + frac technology allowed for successful selective re-injection of acid and proppant into the selected intervals of the horizontal borehole. By now, Bashneft-Dobycha has refractured 10 multistage horizontal wells by means of the abrasive jet perforation + frac technology. One trip included three refrac stages maximum. All the treatment were successful, substantially increasing well productivity indices.
Integrated Approach to Multistage Fracturing Design
Authors: Andreev Alexey , Astafyev Vladimir , Samoilov Mikhail 
Published: October 2020

AbstractWith the advent of multistage hydraulic fracturing technology, the task of well completion optimization was added to the task of fracture design - selection of well length, number of stages, distance between frac ports. A common approach is to first design the fracture and then optimize well completions with approved fracture parameters. This paper considers an alternative approach where the well completion is selected first, including preliminary fracture parameters, and then the required proppant volume is estimated.For this study, field data from a horizontal well with multistage fracturing were used. Tracer studies were conducted and the results were also used as input information. A reservoir model was then built and the fractures were simulated explicitly using an unstructured grid. The model was history matched, and using the resulting matched model, several scenarios with different well completions and fracture parameters were evaluated.This approach represents a practical workflow, both in terms of field development as well as reliable fracturing modeling and flow rate estimation. The approach allows for the preliminary optimization of well completion, the selection of optimal fracture parameters and, eventually, the calculation of proppant volume.In this paper, the technique is presented on a practical example of an operating well.
Violence–related injuries in a rapidly developing Middle Eastern country: A Retrospective Study from a Level 1Trauma Center
Authors: Mollazehi Monira , El-Menyar Ayman , Mekkodathil Ahammed , Consunji Rafael , Al-Thani Hassan 
Published: October 2020

Abstract
Background: Violence is a global public health problem leading to injuries, long-term physical, sexual or mental health problems and mortality. The burden of violence-related injuries remains understudied in the Arabian Gulf region. The present study aimed to describe the epidemiology of hospitalized violence-related injuries in Qatar.Methods: A retrospective analysis of trauma registry data from a level 1 trauma center was conducted by including all patients admitted to the hospital for violence-related injuries between June 2010 and June 2017. We analyzed and compared the hospitalized interpersonal and self-inflicted violence groups.Results: The hospitalization rate of violence-related injuries was 4.6 per 100,000 population per year; it was significantly higher in males (5.5/100,000 males/year vs. 1.8/100,000 females/year) and in younger populations, specifically in the 25-34 years age-group (41%). South Asians constituted 55% of the affected study population. Interpersonal violence (76.7%) was the most common mechanism of injury. Significant differences between interpersonal and self-inflicted violence were evident, especially for the type of trauma (i.e. blunt or penetrating), injured body regions, alcohol use, injury severity, need for intubation and psychiatric referral (p<0.05). Overall, in-hospital mortality was 6.4%; with a significantly higher rate in females (16% vs.5%, p=0.001). Outcomes, including length of hospital stay and mortality, were comparable in the two types of violence. Multivariate analysis showed that male gender and alcohol use were predictors for interpersonal violence whereas a high Injury Severity Score and a low Glasgow Coma Scale were predictors of hospital mortality.Conclusions: The rate of hospitalization for violence-related injuries in Qatar is low; however, its burden on the trauma system is of concern. Although it comprised only 9.6% of the study population, females are more likely to get hospitalized following self-inflicted injuries when compared to interpersonal violence. Disproportionate burden of violence in the South Asians and young population warrants an evidence-based public health approach in violence prevention to well address the risk factors.
A unique type of fully covered metal stent for the management of post liver transplant biliary anastomotic strictures
Authors: Warner Ben , Harrison Phillip , Farman Muhammad , Devlin John , Reffitt David , El-Sherif Yasser , Khorsandi Shirin E , Prachalias Andreas , Cerisuelo Miriam Cortes , Menon Krish , Jassem Wayel , Sriniva Parthi , Vilca-Melendez Hector , Heneghan Michael , Heaton Nigel , Joshi Deepak 
Published: October 2020

Abstract
Background: We report our experience of treating anastomotic strictures using a novel type of fully covered metal stent (FCSEMS). This stent, known as the Kaffes Stent, is short-length with an antimigration waist and is easily removable due to long retrieval wires deployed within the duodenum. Methods: 62 patients underwent ERCP and Kaffes stent insertion for post-transplant anastomotic strictures following confirmation of a stricture on MRCP. These patients were retrospectively analysed for immediate and long-term stricture resolution, improvement in symptoms and liver function tests (LFTs), stricture recurrence and complication rates. Results: Of the 56 patients who had their stent removed at the time of analysis, 54 (96%) had immediate stricture resolution and 42 continued to have long-term resolution (mean follow-up period was 548 days). Of the 16 patients with symptoms of biliary obstruction, 13 had resolution of their symptoms. Overall, there was a significant improvement in LFTs after stent removal compared to before stent insertion. Complication rates were 15% with only one patient requiring biliary reconstruction. Conclusions: The Kaffes stent is effective and safe at resolving post liver transplant biliary anastomotic strictures.
The effect of socioeconomic status among adult married females on informal caregiving for parents: Evidence from China
Authors: Wang Yi , Li Jiajia , Ding Lulu , Feng Yuejing , Tang Xue , Sun Long , Zhou Chengchao 
Published: October 2020

Abstract
Background: Married female caregivers face a higher risk of informal care burden. There is no study to explore the effect of socioeconomic status (SES) among married female caregivers on informal care intensity in China. The purpose of this study is to empirically examine how the SES of married female caregivers affects the amount of informal care they provide for their parents/in-law in China.Methods: 8 waves of the China Health and Nutrition Survey were pooled, and that the selection comprised only those women whose parents/in law had a need for care and were living in the same city. Informal caregivers were divided into three categories: non-caregivers (0 hrs/week), low-intensity caregivers (less than 10 hrs/week), and high-intensity caregivers (10 hrs/week and above). Chi-square tests and one-way analysis of variance (ANOVA) were used to compare the SES of the women between non-, low-, and high-intensity caregivers. Multinomial logistic regression analysis was used to calculate relative risk ratios (RRR) for various SES variables to assess the relation of SES on the likelihood of a low- and high-intensity caregiving in the household, adjusting for age, marital status, family characteristics and wave. Results: Of the 2741 respondents, high-intensity and low-intensity caregivers account for 16.42% and 21.38% respectively. Multinomial logistic regression result shows that the likelihood of being a high-intensity caregiver versus (vs.) a non-caregiver increases as the caregiver’s education attainment increases (p<0.05), and high income is related to the likelihood of being a high-intensity caregiver, but it is only significant at 10% level. Urban females are 1.34 times more likely than their rural counterparts to provide low-intensity care vs. no care (p<0.05) and are 1.34 times more likely to provide high-intensity care vs. no care (p<0.05). Employed females are 1.27 times more likely than those non-employed to provide low-intensity care vs. no care (p<0.05).Conclusions: Differences in SES are found between high-intensity caregivers and low-intensity caregivers. Women with high educational attainment and urban Hukou are more likely to provide high-intensity informal care, and women who are employed and with urban Hukou are more likely to provide low-intensity care.
Candida prevalence and oral hygiene due to orthodontic therapy with conventional brackets
Authors: Grzegocka Kinga , Krzyściak Paweł , Hille-Padalis Anna , Loster Jolanta E. , Talaga-Ćwiertnia Katarzyna , Loster Bartłomiej W. 
Published: October 2020

Abstract
Background: Conventional brackets are often used during orthodontic therapy of patients with malocclusion. The complex construction of such brackets greatly inhibits oral hygiene, which predisposes to increased carriage of microbiota. Orthodontic brackets could act as reservoir of yeast and predispose to oral candidosis. The aim of this study was to assess Candida prevalence and the role of oral hygiene during fixed appliance therapy. A further aim was to characterize the isolated yeasts according to their ability to form biofilms. Methods: Seventeen participants (average age 17 ± 7 years) were monitored by taking oral rinses and elastomeric ligature samples, and by evaluating the approximal plaque index (API) and gingival bleeding index (GBI) before and after placement of the orthodontic conventional brackets for twelve weeks. Isolated yeasts were counted and biofilm formation was evaluated. Results: One hundred and sixteen samples (67 oral rinses and 49 orthodontic elastomers) were collected. Ten patients (58.8% subjects) were Candida-carriers (two were colonized after bracket placement) and C. albicans was the most common species. The average number of yeasts in the oral cavity showed some fluctuation during the study, but in general had an upward trend (adj. R2 = 0.7967, p = 0.07025). A correlation was found between median number of yeasts and the periodontal indices (API, GBI). The average API values decreased in the Candida-carriers (adj. R2 = 0.95; p = 0.01709), while average GBI values increased in the noncarriers (adj. R2 = 0.92; p = 0.0256). Conclusions: Treatment with orthodontic appliances promotes Candida yeast colonization, which is variable over time in terms of strain and species, with dominance of C. albicans, and without increased biofilm-forming activity. The API value decreases over time in carriers, and the GBI value increases in uncolonized patients, which may have predictive significance for the development of oral candidiasis during orthodontic treatment.
Drivers and distribution of forest fires in Sikkim Himalaya: A maximum entropy-based approach to spatial modelling.
Authors: Banerjee Polash 
Published: October 2020

Abstract
The recent episodes of forest fire in Brazil and Australia of 2019 are tragic reminders of the hazards of the forest fire. Globally incidents of forest fire events are in the rise due to human encroachment into wilderness and climate change. Sikkim with a forest cover of more than 47%, suffers seasonal instances of frequent forest fire during the dry winter months. To address this issue, a GIS-aided and MaxEnt machine learning-based forest fire prediction map has been prepared using forest fire inventory database and maps of environmental features. The study indicates that amongst the environmental features, climatic conditions and proximity to roads are the major determinants of the forest fire. Model validation criteria like ROC curve, correlation coefficient and Cohen’s Kappa show a good predictive capability (AUC = 0.95, COR = 0.78, κ = 0.78). The outcomes of this study in the form of a forest fire prediction map can aid the stakeholders of the forest in taking informed mitigation measures.
Adolescent and non-consensual anal sexual debut among Chinese men who have sex with men: a cross-sectional study
Authors: Tang Weiming , Wang Yehua , Huang Wenting , Wu Dan , Yang Fan , Xu Yongshi , Ong Jason J. , Fu Hongyun , Yang Bin , Wang Cheng , Ma Wei , Wei Chongyi , Tucker Joseph D. 
Published: October 2020

Abstract
Background: Adolescent sexual debut and non-consensual sex have been linked to higher sexual risk and STI infection in adulthood among men who have sex with men (MSM) in high-income countries. This study aimed to examine adolescent and non-consensual anal sexual debut among Chinese MSM and to evaluate factors associated with adolescent sexual debut and non-consensual anal sex.Methods: A cross-sectional study was conducted recently among Chinese men assigned male sex at birth, ≥18 years old, and who had ever engaged in anal sex with a man. Participants answered questions regarding socio-demographics, condomless sex, age at anal sexual debut with a man, and whether the first anal sex was consensual. Factors associated with an adolescent sexual debut (<18 years old) and non-consensual sex at sexual debut were evaluated. We defined adolescent sexual debut as having anal sex with another man at 17 years old or younger, and the participants were asked whether their first male-to-male anal sex was non-consensual.Results: Overall, 2031 eligible men completed the survey. The mean age of sexual debut was 20.7 (SD=4.3) years old. 17.6% (358/2031) of men reported adolescent sexual debut, and 5.0% (101/2031) reported a non-consensual sexual debut. The adolescent sexual debut was associated with having more male sexual partners (adjusted OR 1.10, 95% CI 1.06–1.15) and condomless anal sex in the last three months (AOR=1.71, 95% CI 1.34-2.18). MSM whose sexual debut was non-consensual were more likely to have condomless anal sex (AOR=1.76, 95% CI 1.17-2.66), and to have reported an adolescent sexual debut (AOR=2.72, 95% CI 1.75-4.21).Conclusions: Many Chinese MSM reported adolescent sexual debut and non-consensual sex, both of which are associated with sexual risk behaviors and drive STI transmission. These findings highlight the need for designing tailored interventions for MSM who experienced adolescent sexual debut and non-consensual sex at debut.