bluuebunny/crossref_metadata_2025_split huggingface dataset:
Acoustic Telemetry Network Provides Real-Time Downhole Data Transmission During Drilling, Cementing and Completion Installation for Use in Depleted Reservoirs and During Managed Pressure Operations
Authors: Hawthorn Andy , Groves Duncan 
Published: March 2019

Abstract
The last several years has seen an increasing trend toward more depleted reservoirs and more challenging wells with tighter mudweight windows. Managed Pressure Drilling has been employed in these challenging well conditions, however industry take up has been slow for a number of reasons including technical, economic and deployment related. Those wells that have utilized Managed Pressure Drilling have tended to focus on the drilling related aspects of well construction. However, other areas of well construction such as casing and liner running and cementing and completion installation are equally and in some cases even more technically challenging. One area that has potentially hindered the uptake of Managed Pressure Drilling is that in general, and in particular in the well construction operations outside of on bottom drilling there has been no access to real-time downhole data. In particular this is related to real-time pressure data. Whilst cementing, displacing or completing then multiple fluid types and densities may be circulating both inside and outside the drillpipe, leading to significant challenges in simulations and models derived from surface data.
To overcome this a new acoustic telemetry and measurement network is being deployed in depleted reservoir and managed pressure drilling operations to provide real-time downhole and along string measurements of pressures, temperatures and weights. Real-time data case histories will be shown from the Gulf of Mexico and the North Sea illustrating how this is being used to drive real-time decisions during drilling, cementing and completion installation operations in tight margin windows, depleted reservoir conditions and under managed pressure drilling operations.
Wireline Logging in Managed Pressure Drilling Well on a DP Rig
Authors: Mendes Sales Ivan , Dantas Sitonio guedes Jonas , Alexandre Martinello Isac , Couto Lemgruber Kropf Talles , Mesquita Caetano Leonardo , Alonso Fernandes Andre , Loures Sa Lucas 
Published: March 2019

Abstract
MPD techniques have being applied to drill zones with major fluid losses or narrow operational window. Nevertheless, subsequent operations are not yet at the same stage of development: Wireline logging, running casing and cementing are still challenging and need further development when it comes to DP rigs. Therefore, after drilling a well with hydrostatically underbalanced fluid and surface backpressure, it is necessary to replace the drilling fluid in order to continue the operations. Although, in nearly all MPD wells it is possible to do this, the major challenges are zones with absent drilling window and severe losses where PMCD technique is required. In these cases, it is not possible to use overbalanced drilling fluid. This paper presents a solution for wireline logging while using MPD techniques on DP rigs with underbalanced drilling fluid. At first, it shows the planning phase and its discussion, then the execution phase with its difficulties.
Lessons Learned with Real Integration of a Deepwater MPD Control System
Authors: Hovland Svein , van Kuilenburg Robert , Eide Trym , Stridsklev Christian , Munro Colin 
Published: March 2019

Abstract
This paper presents design, testing, installation, and lessons learned with the world's first completely integrated managed pressure drilling (MPD) control system on a deepwater drilling rig. While previous MPD installations have included driller-operated systems, they all include additional human machine interfaces (HMI) and standalone control network components with limited use of rig data and limited to no interfaces to other critical drilling machines on the drilling rig.
For the installation described in this paper, all MPD control functions were permanently installed on the main drilling control network of the drilling unit, providing direct access to high speed data from other drilling machines that influence the wellbore pressure. This includes the rig's mud pumps, top drive, and drawworks. Moreover, the MPD control system has the ability to actively control the drilling machines, thereby optimizing performance through coordinated control of mud pump, top drive, and MPD chokes during drilling and connections.
During the development phase, the specific drilling control system for the vessel was replicated in a hardware-in-the-loop environment, including all the main PLC software for the drilling machinery and supporting subsystems such as logging servers. This approach greatly reduces the risk of errors during installation, commissioning, and operation.
The most essential MPD parameters and control set-points are included in the standard drilling screen for immediate overview and monitoring, with the ultimate goal being a robust and advanced, but low OPEX MPD deployment, delivered by the drilling contractor.
Experience from Drilling a Horizontal Well in a Naturally Fractured and Karstified Carbonate Reservoir in the Barents Sea Using a CML MPD System
Authors: Tangen Geir Ivan , Smaaskjaer Geir , Bergseth Einar , Clark Andy , Fossli Børre , Claudey Eric , Qiang Zhizhuang 
Published: March 2019

Abstract
In 2015, while coring in the carbonate reservoir in the second appraisal well on an oil and gas discovery in the Barents Sea (386 m water depth), the drill string fell 2 meters and a total mud loss was experienced leading to a well control incident. As a result, since 2016, the operator has introduced and used the Controlled Mud Level (CML) system. To date this system has been used on seven wells including two further appraisal wells on the same field and five exploration wells in the area.
In 2017 it was decided to drill a horizontal well in the same carbonate reservoir and to perform an extended production test in close proximity to the original loss well. Since it is not possible to predict where large voids (karsts) and natural fractures could be encountered, contingency to handle high losses, had to be implemented for the horizontal well. During the well planning, further risk reducing measures were implemented, including the use of wired drill pipe to improve the management of the wellbore pressure profile. This paper describes the planning processes leading up to the operation and the highlights of the operation itself together with the lessons learned. It elaborates on how wired pipe, used in combination with the CML system, added value to the operation. It shows how it was possible to drill the reservoir section with a low overbalance while managing severe losses associated with open karsts and natural fractures and still maintaining the fluid barrier. Despite the severe losses encountered it was possible to safely drill and complete the well without any well control event by use of the CML system.
Development of a Practical Tool to Generate Influx Management Envelopes IME for MPD Field Operations
Authors: Helmi Mohamed , Cadd Michael 
Published: March 2019

Abstract
To safely plan and execute MPD Influx Control operations, the limits of the primary barrier envelope must be communicated and understood. These safe operating limits have historically been represented with an MPD Operations Matrix. More recently, the development of the Influx Management Envelope (IME) has provided a means of communicating the primary barrier limits with improved accuracy and clarity. However, the generation of the IME currently requires performing a series of complex well control simulations with specialist engineering support. Because drilling operations are dynamic in nature, a practical method to generate the IME boundaries at the wellsite is required so that changes to mud weight, flowrate, surface and bottom hole circulating temperatures, trajectory, and bit depth can be accounted for, and the IME kept up to date.
This paper describes the development of a novel tool to quickly and automatically generate IMEs at the wellsite without the need for sophisticated modelling software and specialist personnel. The single bubble derivation that was originally presented by Culen et al was analysed further to obtain a more accurate and explicit relationship rather than an implicit one, which forms the basis for the calculations. The IME can be updated based on any well parameter changes, which allows field engineers to maintain an up to date and accurate IME throughout MPD operations.
Evolving Well Control Procedures with MPD on Floaters
Authors: Fernandes Andre Alonso , Vanni Guilherme Siqueira , Martinello Isac Alexandre , Terra Felipe de , Sales Ivan Mendes , Guedes Jonas , Vasconcelos Kelliton da 
Published: March 2019

Abstract
Manage Pressure Drilling is not a new technology, but the transition from land operation to floaters is still recent. This created a situation where drilling contractors and operators are still learning what the true capabilities of the technology are.
MPD technology adoption on floaters can be divide it in 3 different phases: Use for Early Kick Detection and wellbore stability improvement;Introduction of Hydrostatically Underbalanced fluid;Influx circulation through the MPD system;
In the first phase most of the procedures and barrier concepts stay untouched.
After eliminating initial skepticism, second phase commences. Hydrostatic pressure exerted by the fluid is inferior to the formation pressure. Primary barrier concept alters. The technology can be applied to drill wells with narrow operational windows, unviable conventionally.
Finally, third phase starts with very limited volumes being allowed to be circulated through the MPD system. After first successful influx circulations through the MPD system, increased volumes may be encouraged to be circulated through the primary barrier.
Using Managed Pressure Drilling and Early Kick/Loss Detection System to Execute a Challenging Deepwater Completions Job in the Gulf of Mexico
Authors: Hernandez Julian , Arnone Maurizio , Valecillos Juan , Vives Javier , Vannoort Roger , Groves Duncan , Hawthorn Andy 
Published: March 2019

Abstract
Managed Pressure Drilling (MPD) technology was used to successfully drill challenging hole sections, and to run and cement casing strings for a deepwater campaign in the Gulf of Mexico. Because this technology offered the advantages of precisely manipulating the annular pressure using a statically underbalanced mud weight within a narrow pressure window, MPD was also employed along with real-time downhole measurements (from XACT), to run the lower completion assembly into the drilled production interval and perform downhole operations.
For this specific case, the prognosed pressure operating window was around 100 psi, however; the actual window was found to be 50 psi when losses were encountered while drilling the openhole section through the target reservoir. Consequently, the completions operations required the most accurate modeling and planning to keep losses at an acceptable rate while avoiding an influx or formation collapse. MPD was utilized to precisely manage downhole pressures while running the lower completions assembly, displacing the drilling mud with completions fluids in the openhole section, and monitoring losses during the breaker acid job.
A complex pump schedule was created by analyzing the pressure at several critical points in the open hole. Through back pressure management and high-resolution losses rate seen through the Coriolis flow meter, these losses were kept at a reasonable level to avoid breaching the pore pressure gradient and the wellbore stability limit. This paper describes the planning and execution processes that made this deepwater managed pressure completion job a success.
Prevalence of sleep disorders in Parkinson’s disease patients in Ethiopia
Authors: Melka Dereje , Tafesse Abenet , Bower James H. , Assefa Demeke 
Published: March 2019

Abstract
Background: Non motor symptoms (NMS) of Parkinson’s disease (PD) are common and can be more disabling than motor symptoms.Sleep disorders can be seen in up to 98% of patients with Parkinson disease. Poor sleep quality has been associated with poverty and race, and yet there has been no prior report on sleep disorders in those with PD living in sub Saharan Africa. We wished to document the prevalence of sleep disorders in PD patients in Ethiopia. Methods: We conducted a cross-sectional point prevalence study from July 1 to October 30, 2015 of all patients attending the neurology outpatient department in Tikur Anbessa and Zewuditu Memorial Hospitals, Addis Ababa, Ethiopia. Demographic data, clinical history and physical examination findings were collected from participants using a structured questionnaire. We used the Parkinson’s disease sleep scale version two (PDSS-2) and Epworth Sleepiness Scale (ESS) to assess the sleep symptoms. Results: Of the 155 patients surveyed, all patients reported some sleep problem. Over 43.9% of patients had a PDSS score > 18. Presence of previous history of sleep disturbance before PD motor symptoms (OR 3.54; 95% CI 1.61-7.76, p=0.001) and unemployment (OR 2.27; 95% CI 1.07-4.79, p=0.023) associated with a high PDSS-2 score. The median score of ESS was 9 (IQR = 5-12), with 77/155 (49.7%) of the patients having possible or definite excessive daytime somnolence. Conclusions: In Ethiopian PD patients, the prevalence of those with severe sleep disorders is the highest reported to date. The prevalence of possible/definite EDS is amongst the highest in the world. Further investigation into whether poverty or race explains this finding is needed.
Effects of Prophylactic Swallowing Exercises on Dysphagia and Quality of Life in Patients with Head and Neck Cancer Receiving (Chemo) Radiotherapy
Authors: Guillen-Sola Anna , Bofill-Soler Neus , Marco Ester , Pera-Cegarra Oscar , Foro Palmira 
Published: March 2019

Abstract
Background: Squamous carcinoma of the head and neck (HNC) has a high incidence in our context. Although therapeutic radiotherapy protocols try to preserve swallowing function and essential speech organs, dysphagia is a frequent symptom in the acute and long-term phases, due to the toxic effects of therapies needed to confront the illness. Some studies have shown prophylactic oropharyngeal exercises to be quite useful in improving swallowing function after completion of chemo-radiation therapy (CRT) protocols; others have focused on their use to prevent or minimize post-CRT swallowing dysfunction. Patients’ quality of life deteriorates greatly during CRT, with a peak of maximum intensity during the days immediately after finishing CRT treatment. Afterwards, function gradually improves, although scope or timeframe remains undetermined. Available evidence suggests that exercise therapy prior to oncological treatment could potentially improve deglutition and quality of life; however, a randomized study is needed to confirm this observation.
Design/Methods: The Redyor singe-blind randomized clinical trial is designed to compare the effect of prophylactic oropharyngeal exercises on quality of life, dysphagia, and sustainability to the length of rehabilitative treatment. At enrollment, participants will be randomly assigned to one of two treatment groups. Both groups follow the protocol described here, although one group begins the training 2 weeks before initiating CRT and the other group just after finishing the therapy. Both groups will complete standard swallow therapy for training submental muscles involved and 3 sets of 5 inspiratory and expiratory repetitions using the Orygen Dual® valve, with a progressive weekly increase in workload.
Discussion: This ongoing clinical trial, registered in 2016, is based on the hypothesis that undergoing a pre-radiotherapy rehabilitation (pre-habilitation) program will have greater benefits (less decrease in quality of life, less delay in swallowing parameters, and less severe dysphagia) compared to post-CRT rehabilitation. The primary objective is to assess dysphagia severity and evaluate quality of life due to swallowing dysfunction in HNC patients. Secondary objectives are to assess the correlation between a clinical variable and instrumental parameters in this period
Statistical analysis plan for early mobilisation by head-up tilt with stepping versus standard care after severe traumatic brain injury – a randomised clinical feasibility trial
Authors: Riberholt Christian Gunge , Gluud Christian , Jakobsen Janus Christian , Mehlsen Jesper , Møller Kirsten 
Published: March 2019

Abstract
Background: Early mobilisation on a tilt table with stepping versus standard care may be beneficial for patients with severe brain injury, but data from randomised clinical trials are lacking.

Methods: This statistical analysis plan describes the analyses of the data collected in the randomised clinical feasibility trial for early mobilisation by head-up tilt with stepping versus standard care after severe traumatic brain injury. The primary feasibility outcomes are the proportion of included participants who were randomised compared with all screened patients; the proportion of participants allocated to the experimental intervention who received at least 60% of the planned exercise sessions; and safety outcomes such as severe adverse events and reactions and adverse events and reactions. Exploratory clinical outcomes are suspected unexpected severe adverse reactions, the coma recovery scale – revised, the early functional ability scale, and the functional independence measure. Explorative physiological outcomes are electrocardiography, mean arterial pressure, middle cerebral artery blood flow velocity all obtained during the head-up tilt test. From the first head-up tilt test and five days onwards, a continuous electrocardiographic heart rate was measured. The detailed description includes the statistical analysis including use of multiple imputation and Trial Sequential Analysis.

Conclusions: The present statistical analysis plan serves to minimise potential trial reporting bias and selective P hacking and to improve transparency. This feasibility trial will be used for deciding to launch and designing a larger multicentre randomised clinical trial.

Trial registration: ClinicalTrials.gov identifier: NCT02924649. Registered on 3 October 2016.
Textural and chemical variations of micas as indicators for tungsten mineralization: Evidence from highly evolved granites in the Dahutang tungsten deposit, South China
Authors: Yin Rong , Han Li , Huang Xiao-Long , Li Jie , Li Wu-Xian , Chen Lin-Li 
Published: March 2019

Abstract
The Dahutang tungsten deposit, located in the Yangtze Block, South China, is one of the largest tungsten deposits in the world. Tungsten mineralization is closely related to Mesozoic granitic plutons. A drill core through a pluton in the Dalingshang ore block in the Central segment of the Dahutang tungsten deposit shows that the pluton is characterized by multi-stage intrusive phases including biotite granite, muscovite granite, and Li-mica granite. The granites are strongly peraluminous and rich in P and F. Decreasing bulk-rock (La/Yb)N ratios and total rare earth element (ΣREE) concentrations from the biotite granite to muscovite granite and Li-mica granite suggest an evolution involving the fractional crystallization of plagioclase. Bulk-rock Li, Rb, Cs, P, Sn, Nb, and Ta contents increase with decreasing Zr/Hf and Nb/Ta ratios, denoting that the muscovite granite and Li-mica granite have experienced a higher degree of magmatic fractionation than the biotite granite. In addition, the muscovite and Li-mica granites show M-type lanthanide tetrad effect, which indicates hydrothermal alteration during the post-magmatic stage. The micas are classified as lithian biotite and muscovite in the biotite granite, muscovite in the muscovite granite, and Li-muscovite and lepidolite in the Li-mica granite. The Li, F, Rb, and Cs contents of micas increase, while FeOT, MgO, and TiO2 contents decrease with increasing degree of magmatic fractionation. Micas in the muscovite granite and Li-mica granite exhibit compositional zonation in which Si, Rb, F, Fe, and Li increase, and Al decreases gradually from core to mantle, consistent with magmatic differentiation. However, the outermost rim contains much lower contents of Si, Rb, F, Fe, and Li, and higher Al than the mantle domains due to metasomatism in the presence of fluids. The variability in W contents of the micas matches the variability in Li, F, Rb, and Cs contents, indicating that both the magmatic and hydrothermal evolutions were closely associated with W mineralization in the Dahutang deposit. The chemical zoning of muscovite and Li-micas not only traces the processes of W enrichment by magmatic differentiation and volatiles but also traces the leaching of W by the fluids. Therefore, micas are indicators not only for the magmatic–hydrothermal evolution of granite, but also for tungsten mineralization.
Impact of land use on water resources via a Gaussian process emulator with dimension reduction
Authors: Owen Nathan E. , Liuzzo Lorena 
Published: March 2019

AbstractThe replacement of models by emulators is becoming a frequent approach in environmental science due to the reduction of computational time, and different approaches exist in the water resources modelling literature. In this work, an emulator to mimic a hydrological model at catchment scale is proposed, taking into account the effect of land use on the hydrological processes involved in water balance. The proposed approach is novel for its combination of techniques. The dimension of the temporal model output is reduced via principal component analysis, and this reduced output is approximated using Gaussian process emulators built on a conditioned Latin hypercube design to reflect constrained land use inputs. Uncertainty from both the model approximation and the dimension reduction is propagated back to the space of the original output. The emulator has been applied to simulate river flow in a rural river basin located in south west England, the Frome at East Stoke Total, but the methodology is general. Results showed that the use of the emulator for water resources assessment at catchment scale is an effective approach, providing accurate estimates of the model output as a function of land use inputs, for a reduction of the computational burden.
The impact of household connection to public network wastewater systems: regulatory impact assessment
Authors: de Carvalho Bruno Eustaquio , Costa Samuel Alves Barbi , Marques Rui Cunha , Netto Oscar Cordeiro 
Published: March 2019

Abstract
Brazil faces a severe lack of wastewater coverage. Even in urban areas, wastewater is directly disposed of in watercourses without any treatment for a large part of the population. Although the federal, state, and local governments have invested in water and wastewater services (WWS), the expected results have not been achieved. To overcome this problem, the present paper provides an opportunity to observe an ex-ante regulatory impact assessment (RIA) as a policy tool in Brazil. The regulatory policy options will be appraised through the multiple criteria decision analysis (MCDA) according to the following objectives: (i) protect the customers with respect to social aspects; (ii) safeguard the economic, operational and infrastructure sustainability; and (iii) protect the environment. The results show that by making decisions based on evidence, policy makers should reduce the households not connected to wastewater services by 75% and for that they should incur BRL 33 million to the year 2023. Hence, the extra revenues to be obtained with these new connections are capable of making a surplus estimated as BRL 42 million for the same period. This study promotes the use of RIA as a rational, robust and transparent decision framework by the regulatory agencies worldwide.