bluuebunny/crossref_metadata_2025_split huggingface dataset:
NÜKS PRİMER SPONTAN PNÖMOTORAKS TEDAVİSİNDE İKİ FARKLI MEKANİK PLEVRAL ABRAZYON YÖNTEMİNİN KARŞILAŞTIRILMASI
Authors: ESME Hıdır 
Published: October 2020

Amaç
Nüks primer spontan pnömotoraksın cerrahi tedavisi,
apikal bül rezeksiyonu ve plörodezisi içerir. Postoperatif
nüks oranları %5 ile %10 arasında bildirilmektedir.
Bu çalışmada, kliniğimizde uyguladığımız iki farklı mekanik
plevral abrazyon yönteminin etkinliğini ve nüks
oranlarını karşılaştırmayı amaçladık.
Gereç ve Yöntem
Ocak 2012 ve Aralık 2019 tarihleri arasında 112 hastaya
primer spontan pnömotoraks için cerrahi tedavi
olarak videotorakoskopik bül rezeksiyonu ve paryetal
plevra abrazyonu uygulandı. Hastaların yaş, cinsiyet,
sigara içme hikayesi, ameliyat nedeni, ameliyatta bül
varlığı, plörodez yöntemi, göğüs tüpü drenaj süresi,
hastanede yatış süresi, ameliyat sonrası komplikasyonlar,
ameliyat sonrası nüks ve takipleri geriye dönük
olarak incelendi.
Bulgular
Ameliyat endikasyonu, hastaların 91’inde (%81.2) nüks
pnömotoraks iken 21’inde (%18.7) 7 günden fazla devam
eden uzamış hava kaçağı idi. Paryetal plevraya
mekanik plöredezis için abrazyon; 38 (%33.9) hastada
gazlı bez ile uygulanırken, 74 (%66.1) hastada steril
zımpara ile uygulandı. Paryetal plevra abrazyonu için
steril zımpara kullandığımız grupta göğüs tüpü drenaj
süresi, gazlı bez kullandığımız gruba göre istatistiksel
olarak anlamı derecede yüksekti. Ancak steril zımpara
kullandığımız grupta, nüks ve takip süresi istatistiksel
olarak anlamlı derecede düşüktü. Diğer parametreler
açısından iki grup arasında istatistiksel olarak anlamlı
bir ilişki saptanmadı.
Sonuç
Sonuç olarak nüks primer spontan pnömotoraks veya
uzamış hava kaçağı tedavisinde videotorakoskopik
bül rezeksiyonu ve plevral abrazyon, düşük nüks oranı
ile güvenli bir yöntemdir. Ayrıca paryetal plevra abrazyonu
için steril zımpara kullanımı göğüs tüpü drenaj
süresini bir miktar artırmakla birlikte daha az nüks oranına
sahiptir.
CLINICAL AND RADIOLOGICAL EVALUATION IN RARE PRIMARY MALIGNANT TUMORS OF THE LUNG
Authors: ÖZ Gürhan , ÖZDEMİR Çiğdem , AYDIN Suphi , DUMANLI Ahmet , GÜNAY Ersin , ÇİLEKAR Şule , GÜNAY Sibel , GENCER Adem , ÖZTÜRK Düriye , DEMİRAĞ Funda 
Published: October 2020

Objective
The most common primary malignant tumors of the
lung are squamous cell carcinoma, small cell carcinoma
and adenocarcinoma. However, some rare malignant
primary lung tumors can also affect the lung
and cause difficulties in diagnosis and treatment.
Conventional imaging methods do not help the diagnosis
in most cases, and moreover, preoperative
tissue samples may fail to establish a diagnosis. In
cases with endobronchial lesions, small samples or
lack of transthoracic biopsy in central tumors without
endobronchial lesions can make diagnosis difficult.
The definitive diagnosis can only be made after larger
examinations with larger tissue samples taken after
the operation. In addition, failure to differentiate benign-
malignant in frozen examination may negatively
affect the resection of the surgeon. It can cause incomplete
or unnecessary resection.
The aim of this study was to evaluate the clinical radiological
and histopathological features of these tumors,
which have been rarely reported in the literature,
and to contribute to the diagnosis and treatment of
these tumors.
Material and Methods
The study included 10 patients with rare malignant
primary lung tumor who were operated on in our clinic
between 2010 and 2019. All patients were retrospectively
evaluated in respect of age, gender, symptoms,
preoperative imaging methods and invasive diagnostic
methods. Tumor localization, tumor size, type of
surgical operation and survival were recorded.
Results
The 10 patients included in the study comprised 6
males and 4 females. Postoperative histopathological
diagnoses of the patients were reported as 2 carcinosarcomas,
2 large cell carcinomas, 2 epithelioid
hemangioendothelioma, 1 glomangiosarcoma, 1 primary
pulmonary leiomyosarcoma, 1 mucoepidermoid
carcinoma, and 1 synovial sarcoma.
Conclusion
It can be difficult to diagnose in rare primary malignant
lung tumors by preoperative imaging and preoperative
invasive diagnostic methods. CT-guided fine needle
biopsy and tru-cut biopsy, endobronchial biopsy
and frozen samples performed before surgery may be
insufficient in diagnosis, which may mislead the surgeon
about lung resection.
Influence of the Site-Specific Component of Kappa on the Magnitude-Dependency of Within-Event Aleatory Variabilities in Ground-Motion Models
Authors: Brooks Christopher , Douglas John 
Published: October 2020

AbstractThe aleatory-variability component (standard deviation) of a ground motion has a large influence on results of a probabilistic seismic hazard assessment. kappa, a measure of high-frequency attenuation, has site- and record-specific effects that have been suggested as reasons for observing heteroscedastic aleatory variability within earthquake ground motions. Specifically, kappa has been proposed as a reason why ground motions from small earthquakes are more variable than those from large earthquakes, which is modeled by magnitude-dependent within-event standard deviations in ground-motion prediction equations (GMPEs). In this study, we use ground motions simulated using the stochastic method to examine the influence of the site-specific component of kappa on aleatory variability of earthquake ground motions and examine the hypothesis that this could be a cause of the observed heteroscedasticity in this variability. We consider simulations with both fixed and continuous stress drop distributions and the site-specific component of kappa to demonstrate that variation in the stress drop parameter contributes minimally to magnitude-dependency, unlike the site-specific component of kappa, which causes significant magnitude-dependency. Variation in the site-specific component of kappa is, therefore, proposed to be at least partially responsible for the magnitude-dependency captured in the aleatory-variability components of some recent GMPEs. It is found, however, that the expected impact of the site-specific component of kappa on aleatory variability is much greater than modeled in these GMPEs, which suggests that there could be a mitigating effect that is not captured within the simulations (e.g., correlated inputs to the simulations).
Successful Mitigation of Negative Parent-Child Wells Interaction Using Far-Field Diversion in the Delaware Basin
Authors: Defeu Cyrille , Galt Aaron , Williams Ryan , Green Larrez , Valle Laine , Sethi Richa 
Published: October 2020

Abstract
Recent industry analysis based on publicly available production data of most unconventional basins in the US have consistently highlighted the underperformance of child wells as compared to parent wells, although completion practices have continuously evolved. Industry publications have suggested that average productivity degradation of child wells can be up to 29% for some Delaware Basin operators. In some cases, the detrimental effects of parent-child relationships have also been observed on the parent wells after the stimulation of the child wells. In such an environment it is important to develop completion strategies to mitigate the negative effects of this parent-child relationship. In the Delaware Basin, the negative parent-child effect was successfully mitigated on two different zipper pads, with parent wells as close as 500 ft away from the zippered child wells. On the first pad, one parent well was completed and six months later two child wells were zippered with the closest child 1,000 ft away from the parent and pumped with far-field diversion. On the second pad, one parent well was completed and four months later three child wells were zippered with the closest child well 500 ft away from parent and far-field diversion pumped on the two closest child wells.
The stimulation treatment design was carefully designed to include far-field diverters on the stages near parent wells. Job size and far-field diverter quantity were determined using an integrated hydraulic fracture simulation software with an advanced particle transport model. Contingency scenarios were also prepared to facilitate real-time changes required when or if abnormal behavior was observed during the execution. The zipper sequence was also planned to help establish a stress-shadow effect near the parent well to further mitigate detrimental parent-child interactions. To monitor execution in real time and evaluate interactions between wells, high-frequency pressure gauges were installed on all observation wells including parent and child wells.
The completion design and far-field diversion treatment worked as planned for the first pad, with no significant well interference pressure signature observed on the monitoring well. For the second pad, the parent well saw pressure increases up to 700 psi during the treatment of a stage midway along the lateral of the closest child well which was completed with far-field diverter. Contingency plans were successfully executed, and no significant pressure increase was observed on the remainder of the lateral. Early production results indicate that the negative impacts of parent-child interactions were successfully mitigated on both pads, with the production of the parent wells quickly returned to their observed trends prior to child wells stimulation. Child wells production, when normalized both by lateral length and stimulation size, was on par with that of the parent well.
PACT – Cost Effective, Digital, Fail-Safe Production Tree and Wellhead Actuator System
Authors: Johansen Espen Sten , Fredheim Dag Ketil , Huuse Tom , Volkers Richard , Hansen Dag Almar , Petersen Christian 
Published: October 2020

Abstract
PACT (Pressure control ACTuator) is a newly developed, all-electric wellhead- and production tree valve actuator for enhanced well control and fail-safe handling of emergency situations. The actuator was developed under a Joint Industry Project (JIP) by Equinor, Baker Hughes and TECHNI.
PACT is designed for mission critical operations offshore and is subject to stringent safety design requirements. The actuator employs a patent pending fail-safe mechanism with extremely fast closing time to ensure containment during emergency shutdown. Opening time is 30 to 60 seconds (depending on valve size) and adjustable closing time of 4 to 8 seconds (valve closing in less than 1 second has been demonstrated). It is designed to be a drop-in replacement for NoBolt™ CHA actuator solutions and is suitable for most standard wellhead and tree designs, sizes and pressure ratings.
Electric actuators offer significant CAPEX savings over hydraulic actuator systems by eliminating the need for costly hydraulic control systems (HPU), associated hydraulic lines and umbilicals as well as saving deck space and weight. Electric actuators also offer significant OPEX savings over hydraulic actuators by eliminating the need for specially trained personnel offshore during periodic testing and associated post-actuation flushing of hydraulic lines. Environmental impact is reduced by eliminating high-pressure hydraulic oil lines with associated risk of spills and removing the need to transport personnel offshore which reduce total CO2 emissions.
The PACT development program was initiated in 2017 and has resulted in an actuator solution at Technology Readiness Level (TRL) 4 (on 0 to 7 scale) with planned TRL 5 testing yielding it ready for field installation.
Computational Fluid Dynamics Model to Improve Sucker Rod Pump Operating Mode
Authors: Jalikop Shreyas V. , Scheichl Bernhard , Eder Stefan J. , Hönig Stefan 
Published: October 2020

Abstract
Artificial lift pumps are widely used in oil production, and among them, sucker rod pumps are conceptually the simplest ones. The reciprocating movement of the plunger triggers the opening and closing of two ball valves, allowing fluid to be pumped to the surface. These valves are subject to long-time erosion and fail as a consequence of this damage mechanism. We demonstrate that understanding the principal damage mechanisms in the necessary depth and breadth requires a thorough examination of the fluid dynamics during the opening and closing action of the ball valves.
This paper describes the basic ingredients and results of fluid–structure interaction model that simultaneously computes the fluid flow in the traveling valve, the standing valve, and the chamber of sucker rod pumps during a full pump cycle in an efficient and accurate way. The simulations provide necessary insight into the causes of valve damage for realistic standard as well as non-ideal operating conditions of the downhole pump. In particular, simulations based on real pump operating envelopes reveal that the phenomenon of so-called ‘‘mid-cycle valve closure’’ is likely to occur. Such additional closing and opening events of the ball valves multiply situations where the flow conditions are harmful to the individual pump components, leading to efficiency reduction and pump failure.
The computational-fluid-dynamics model based on the finite-element method serves to accurately describe the opening and closing cycles of the two valves. Most importantly, this approach for the first time allows an analysis of real operating envelopes, derived from actual dynamometer cards. The combination of stroke length, plunger speed, fluid parameters, and velocity at any point inside the pump can thus be investigated at any time during the pump cycle. The flow parameters identified as critical in terms of damaging pump valves or other pump components can set the basis for taking measures to avoid unfavorable operating envelopes in future pump designs.
Our comprehensive flow model may support field operations throughout the entire well life, ranging from improved downhole pump design to optimized pump operating modes and envelopes as well as in material selections. It is suggested to aid in adapting pump operating conditions to create an ideal interaction between the valves and avoiding the "mid-cycle valve closure". Specifically, a so-optimized pump design is expected to drastically extend the operation time before failure of sucker rod pumps. Finally, this type of simulation will speed up new pump or pump component development, and can eliminate or at least reduce the necessity of extensive and costly laboratory testing.
Controlling Gas Slugs in ESP Using A New Downhole Gas Regulator: Case Studies
Authors: Guanacas Luis , Vyas Shivani , Gonzalez Gustavo , Portilla Carlos 
Published: October 2020

Abstract
Improving ESP performance has become one of the main challenges in gassy wells. Different methods and new technologies have been developed but most of them have high economic value. A new system has been created to prevent large amounts of gas flowing directly into the pump intake through the breaking of the gas slugs and the resolubilization (dispersion) of the free gas into the production liquid. The system contains an isolation section which allows to break gas slugs and pressurize that section forcing the gas to go in solution to be produced afterwards. The concept of the new technology is to manage the Rs (Gas in solution) with pressure, additionally the technology includes a vortex effect creator which will improve the gas dispersion iton the liquid associated and will separate the sand production. The ESP’s Downhole Regulator was designed based on each well conditions to maximize its efficiency. This paper summarizes the design and application of the new Vortex Regulator in more than 50 gassy wells completed in the Wolfcamp A, Wolfcamp B, Lower Spraberry, and Jo Mill C in the Permian basin. The performance evaluation was carried out by a constant monitoring of the sensor parameters through a certain period. During the evaluation period the ESPs in most of the wells were operating under stable conditions with minor shutdowns, no significant increases in the motor current, motor temperature, and vibration were observed.
Modeling Dynamic Loads Induced By Slug Flows Considering Gas Expansion Due To The Pressure Gradient In A Free Span Horizontal Hanging Pipeline
Authors: Meneses Santos Gabriel , Nascimento Bordalo Sérgio , Kazuyuki Morooka Celso 
Published: October 2020

Abstract
Slug flows generate variable loads that excite pipelines, inducing oscillatory displacements and tensions of significant magnitude, raising concerns about the physical integrity of the pipe’s structure. The present paper presents a simulation model to compute non-uniform slugs, to provide a tool for the analysis of the dynamic behavior of horizontal pipelines in subsea petroleum production systems. This model was tested for a straight, horizontal, free span hanging pipeline supported at both ends. The development of the present methodology was based on a previous model of regular slugs. The present model takes into account the expansion of the gas bubble length along the pipeline, generated by the negative streamwise pressure gradient between the pipeline’s entrance and exit, resulting in a longitudinal sequence of non-uniform slugs. The model’s algorithm used to calculate the mass distribution in the slug flow is implemented in a subroutine of a pre-existent software, commonly known to simulate the mechanical behavior of pipelines under dynamic loads. The dynamic responses of a pipeline excited by non-uniform slugs – vertical displacement, bending moment and bending stress – were analyzed as a function of the gas expansion global rate, and were compared to the dynamic responses induced by a regular slug flow. It is concluded that the non-uniform slug distribution imposes a more complex excitation on the pipe, while the perfect regular slug flow induces an excitation with a single well-determined frequency. The difference between irregular and regular flows depends on the magnitude of the pressure gradient acting along the pipeline’s length.
Interpretation of Hydraulic Fracturing Events by Analyzing the Energy of Rate and Pressure Signals
Authors: Awad Mohamed M. , Eltaleb Ibrahim , Mansi Mohamed , Rezaei Ali , Soliman M. Y. , Farouq-Ali S.M. , Dindoruk Birol 
Published: October 2020

Abstract
Hydraulic fracturing rate and pressure data are interrelated signals and can be subjected to signal processing techniques. The energy of a range of frequency band can be computed from the wavelet transform, which is a powerful technique in signal processing. The signal energies of the rate (cause) and pressure (effect) are used to detect the fracture events in time, such as height growth, screen-out, and hydraulic fracture-natural fracture interactions. The objective of this study is to relate the signal energies obtained from the wavelet analysis to the real physical phenomena of fracturing propagation events during injection. With this technique, the fluid injection during hydraulic fracturing process may be monitored in real-time for early diagnosis and to take preventive steps during the fracturing treatment
Wavelet transform decomposes a signal into various levels of frequency components. The transform can be repeatedly applied to obtain a multiresolution analysis of the signal. Such repeated application of the wavelet transform yields the signal detail coefficients at each decomposition level, where each level represents a band of frequency. Using this approach, the pressure and rate signals from hydraulic fracturing were decomposed. Then, the pressure and rate signals energies at each frequency band were computed and compared to using energy density plots (EDP). Since wavelet transform preserves the time localization, all events on the EDP are obtained with respect to time. Finally, the energy distribution of the frequency bands for pressure and rate signals of different decomposition levels and using different wavelet types were studied with respect to time to distinguish between the rock-related and rate-related events in time. The moving reference point (MRP) technique is used to verify the results of our proposed approach.
Several field cases were analyzed in this study to show the robustness of the proposed approach. The events identified using the proposed approach were in good agreement with the established techniques in the literatures such as Nolte-Smith and moving reference point (MRP). The identified events were related to physical events happening during fracture propagation, such as height growth, the opening of the natural fracture system, screen-out, and proppant entering the formation. The main advantage of the developed methodology is its ability to identify fracturing events more accurately and earlier in time than other techniques.
The novelty of this research is detecting the fracturing events in time independently of the assumptions of fracture and well geometry. Ultimately, this technique helps to improve treatment designs and efficiency by analyzing fracture and formation behavior of the treatment and enhancing decision-making during execution, by providing real-time indications of fracture behavior.
Estimation of Gas Condensate Relative Permeabilities for Field Development in Egypt in Absence of Reliable Core Flood Experiments
Authors: Fogden Andrew , Held Rudolf , Morgenstern Rico , Nazarov Roman , Rafiee Mohsen , Shaqlouf Hamada 
Published: October 2020

Abstract
Gas condensate field development is a challenging task involving many technical disciplines, from sedimentology and petrophysics to reservoir and facility engineering. For evaluation of development options in a Nile Delta onshore field with original reservoir pressure close to dew point, reservoir simulation must account for potential condensate blockage near wellbore. Uncertainties related to blockage can severely risk the estimation of gas and condensate reserves and production, and significantly impact project development or even put the investment decision on hold.
The method of Whitson8 for determining velocity-dependent gas-condensate relative permeabilities is sufficiently robust and reliable to model well deliverability in moderately homogenous reservoirs. However, with increasing heterogeneity, gas condensate flow in contrasting facies or thin laminated zones requires deeper investigation. Thin low permeability layers can act as bounding surfaces with condensate dropout below dew point, which may trap initially connected gas volumes. Estimation of gas condensate well deliverability is further complicated if shortage of reservoir core material and fluids precludes reliable coreflood experiments across the full range of pressure/flow regimes.
This paper demonstrates how digital rocks technology can enhance the understanding and de-risk the prediction of gas condensate flow in contrasting rock types and with only limited core material and cuttings at hand. Remnants of sidewall core plugs from earlier laboratory analyses were scanned using X-ray micro-tomography to obtain 3D images down to pore-scale of regions ranging from open to tight. Flow simulations were performed in the pore space of the processed images to reconcile connected porosity, absolute permeability and capillary pressure-saturation curves with laboratory core analysis results, and to refine the rock types ranging from higher to lower reservoir quality. As input to two-phase gas-condensate flow simulation, representative capillary numbers and viscosity ratios were estimated based on PVT and the planned field development options and existing dynamic reservoir model. The dynamic pore-scale simulations yielded gas-condensate relative permeability curves versus rock type and capillary number which agreed well with published literature. The delivery of consistent relative permeability estimates in a short timeframe from this digital rocks approach served to reduce uncertainties in reservoir modeling to de-risk the development planning of the gas condensate field.