370 research outputs found
Estimation of the Free Rotating Hook Load for WOB Estimation
Today’s drilling industry emphasizes safety and deeper drilling while reducing drilling costs. Low rate of penetration (ROP) and non-productive time are two main reasons for reduced drilling efficiency.
Machine Learning (ML) technology has been increasingly used in the Oil and Gas industry for a variety of problems, including drilling parameters estimation and prediction, drilling inci- dents detection, and optimal well planning.
With the abundance of field data available, a number of detailed research studies have been conducted to define the relationship between the ROP and drilling parameters. However, de- veloping a pure data-driven ROP model and optimization remains very challenging. The main reason for this is the number of parameters that affect its estimation, as well as the manner in which different variables are correlated, e.g., the downhole weight on bit (DWOB), rotary speed (RPM), standpipe pressure (SPP), and formation/bit properties [1]. Thus, we suggest breaking down the ROP data-driven problem into its primary parameters and focusing on them separately.
Analyzing time series for hook load when drilling with connections is the purpose of our study. In drilling operations, hook load is used to control the weight on the bit. Due to the in- ability to measure WOB directly during drilling, the tension at the top of the drill string is used to determine WOB. As of now, the industry is letting the driller select manually a free-rotating hookload choice according to his judgment and experience. This task of manual inspection and selection is tedious and, according to experts, often left behind due to the number of tasks at a time the driller has to deal with. This recorded value will be used to calculate the WOB indi- rectly while drilling. With an industry that is more autonomous than ever before, this would not be a viable option, and a different approach is proposed in this research.
In essence, this research is an attempt to estimate automatically and more accurately rather than relying on the experience and judgments of the driller, the free rotating hook load. The approach will be accomplished by developing a hybrid system combining ML algorithms with statistical analysis and physics principles.
As a result of embedding this rig state identification engine idea, we will be able to classify and analyze different real-time data points (e.g., out-of-slips, pick-up, rotating off-bottom, and drilling), obtain the free rotating hook load, and also to utilize it in other applications, such as T&D calibration
Two-dimensional strain field analysis of reinforced concrete D-regions based on distributed optical fibre sensors
The introduction of Distributed Optical Fibre Sensing in experimental testing of reinforced concrete structures has enabled the acquisition of measurements with an unparalleled level of detail, providing an accurate and ubiquitous description of cracking and deflections throughout an element. However, most of the available research using this technology has focused on the study of beam specimens and high quality data for the calibration and development of models that can describe accurately the behaviour of D-regions in service is still lacking. For that reason, the application of distributed optical fibre sensing in D-regions remains a subject of interest. In this work a method for the deployment of fibre sensors in a multilayer configuration is presented for a wall element. An interpolation approach is then proposed, which combined with the distributed nature of the sensors enabled the description of detailed heat maps for the global and principal strain fields. The results indicated that shear strains can reveal the position of shear cracks well before they are formed whereas the maximum and minimum principal strains clearly show the crack pattern and crack development as well as the load transfer mechanisms including, for the first time, the experimental identification of a secondary strut-and-tie mechanisms
Crack monitoring in reinforced concrete beams by distributed optical fiber sensors
This paper investigates the use of distributed optical fiber sensors (DOFS) based on Optical Frequency Domain Reflectometry of Rayleigh backscattering for Structural Health Monitoring purposes in civil engineering structures. More specifically, the results of a series of laboratory experiments aimed at assessing the suitability and accuracy of DOFS for crack monitoring in reinforced concrete members subjected to external loading are reported. The experiments consisted on three-point bending tests of concrete beams, where a polyamide-coated optical fiber sensor was bonded directly onto the surface of an unaltered reinforcement bar and protected by a layer of silicone. The strain measurements obtained by the DOFS system exhibited an accuracy equivalent to that provided by traditional electrical foil gauges. Moreover, the analysis of the high spatial resolution strain profiles provided by the DOFS enabled the effective detection of crack formation. Furthermore, the comparison of the reinforcement strain profiles with measurements from a digital image correlation system revealed that determining the location of cracks and tracking the evolution of the crack width over time were both feasible, with most errors being below +/- 3 cm and +/- 20 mu m, for the crack location and crack width, respectively
Long-term performance of distributed optical fiber sensors embedded in reinforced concrete beams under sustained deflection and cyclic loading
This paper explores the performance of distributed optical fiber sensors based on Rayleigh backscattering for the monitoring of strains in reinforced concrete elements subjected to different types of long-term external loading. In particular, the reliability and accuracy of robust fiber optic cables with an inner steel tube and an external protective polymeric cladding were investigated through a series of laboratory experiments involving large-scale reinforced concrete beams subjected to either sustained deflection or cyclic loading for 96 days. The unmatched spatial resolution of the strain measurements provided by the sensors allows for a level of detail that leads to new insights in the understanding of the structural behavior of reinforced concrete specimens. Moreover, the accuracy and stability of the sensors enabled the monitoring of subtle strain variations, both in the short-term due to changes of the external load and in the long-term due to time-dependent effects such as creep. Moreover, a comparison with Digital Image Correlation measurements revealed that the strain measurements and the calculation of deflection and crack widths derived thereof remain accurate over time. Therefore, the study concluded that this type of fiber optic has great potential to be used in real long-term monitoring applications in reinforced concrete structures
The interplay between corrosion and cracks in reinforced concrete beams with non-uniform reinforcement corrosion
This paper investigates the interplay between corrosion of reinforcement and corrosion-induced cracking in reinforced concrete structures with non-uniform corrosion distribution based on the experimental results of a concrete beam simultaneously subjected to sustained deflection and accelerated corrosion through impressed current. Unlike previous studies, this work encompasses various refined techniques for the measurement of surface cracks, such as digital image correlation and distributed optical fiber sensors, as well as for the assessment of reinforcement corrosion, namely 3D laser scanning, to explore previously hidden aspects of the relationship between the two parameters. The applied techniques proved very effective in providing an unprecedented level of detail of both the crack development and corrosion distribution. More specifically, the formation and propagation of corrosion-induced cracks were accurately and constantly monitored over time and subsequently compared to the distribution of corrosion. The results revealed that determining the maximum corrosion level or even the location of the section with maximum corrosion based solely on visual inspection of the surface crack width may not be possible. However, the width of corrosion-induced cracks was found to increase linearly with the local corrosion level, implying that crack width monitoring can still be used to estimate the rate of corrosion degradation
Comportamiento mecánico ante la sobrexpansión de stents de cromo-cobalto comparados con stents de acero inoxidable, implantados en la aorta abdominal de conejos hipercolesterolémicos
Introducción: La fisiopatología de la disfunción diastólica del ventrículo izquierdo incluye alteraciones de la relajación ventricular, rigidez elástica pasiva o una combinación de ambos mecanismos. Mediante el eco-Doppler es posible evaluar parámetros relacionados con la relajación ventricular, pero no de la rigidez elástica pasiva. El estrés parietal diastólico evalúa la rigidez elástica pasiva a través de la disminución de la compresión del miocardio al final de la diástole. Objetivo: Evaluar la rigidez elástica pasiva mediante el estrés parietal diastólico en pacientes con estenosis aórtica grave con fracción de eyección preservada y su relación con la presencia de insuficiencia cardíaca grado III-IV. Material y métodos: Se estudiaron 76 pacientes (edad promedio 67 ± 11 años) portadores de estenosis aórtica grave (índice de área valvular aórtica <0,6 cm2/m2) y fracción de eyección mayor o igual al 50%. El estrés parietal diastólico fue calculado como: (espesor sistólico de pared posterior – espesor diastólico) / espesor sistólico en modo M. Se calculó por métodos no invasivos la relación E/e´, presión de fin de diástole y presión de fin de diástole / volumen de fin de diástole. Los pacientes fueron ordenados en 2 grupos: Grupo 1: insuficiencia cardíaca grado III - IV (n = 5 pacientes) y Grupo 2: sin insuficiencia cardíaca (n = 71 pacientes). Resultados: Los pacientes del grupo 1 presentaron mayor alteración de la rigidez elástica pasiva evidenciada por disminución del estrés parietal diastólico (0,23 ± 0,05 vs. 0,30 ± 0,06 p < 0,01), mayor incremento de E/e´ (20 ± 7 vs. 14 ± 8 p < 0,05), presión de fin de diástole y presión de fin de diástole / volumen de fin de diástole. Conclusión: El estrés parietal diastólico permitiría objetivar alteraciones de la rigidez elástica pasiva en pacientes con estenosis aórtica grave, fracción de eyección preservada e insuficiencia cardíaca que no pueden ser evaluadas mediante los parámetros de función diastólica habituales.Objectives: The aim of this study was to analyze the behavior to overexpansion of cobalt chromium stents compared with stainlesssteel stents.Methods: Twenty New Zealand rabbits were used, fed with a diet supplemented with 1% cholesterol. Animals were divided into twogroups. Group 1 (n=10) received 3.0 mm cobalt chromium stents overexpanded at 20 atmospheres and group 2 (n=10) 3.5 mm stentsdeployed at 10 atmospheres. These stents were compared with a previous series of 20 animals with stainless steel stents, dividedinto the same two groups. A third group with conventional diet was used as control. Intravascular ultrasound (IVUS) was performedto assess the degree of elastic recoil and also the degree of symmetry using ?intertrust angles?.Results: In group 1 of cobalt chromium stents, mean elastic recoil was 0.11±0.13 mm, (3.21% recoil) and in group 2 this was0.3±0.12 mm, (8.26% recoil) (p=0.002). In group 1 of stainless steel stents mean elastic recoil was 0.28±0.18 mm (8.21% recoil) andin group 2 this was 0.10±0.11 mm (2.79% recoil) (p <0.001).Conclusions: In cobalt chromium stents, elastic recoil was lower in overexpanded stents, whereas in stainless steel stents, elasticrecoil was higher in overexpanded stents. No differences in symmetry were observed between the different groups.Fil: Fernandez, Alejandro. Hospital Italiano; ArgentinaFil: Mele, Esteban. Hospital Italiano; ArgentinaFil: Renou, Sandra Judith. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Anatomía Patológica; ArgentinaFil: Olmedo, Daniel Gustavo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Anatomía Patológica; ArgentinaFil: Berrocal, Daniel. Hospital Italiano; ArgentinaFil: Gelpi, Ricardo Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Odontología. Cátedra de Anatomía Patológica; Argentin
Monitoring of new and existing stainless-steel reinforced concrete structures by clad distributed optical fibre sensing
The implementation of structural health monitoring systems in existing civil engineering structures could contribute to a safer and more resilient infrastructure as well as important savings. Due to their light weight, small size, and high resistance to the environment, distributed optical fibre sensors (DOFS) stand out as a very promising technology for damage detection and quantification in reinforced concrete structures. This dataset includes information of DOFS featuring an external polymeric cladding with rough surface, deployed in a stainless-steel reinforced concrete beam subjected to four-point bending. Several sensor positions, both embedded in the concrete and attached to the surface, are included in a multilayer configuration. The data of the sensors includes two series of test, first cyclic loading under service loads and lastly cyclic loading to failure. Additionally, data from Digital Image Correlation and the actuator recordings are included for cross-validation purposes
Performance requirements for Swedish transport infrastructure - A pre-study of challenges and possibilities
In recent years, significant worldwide research has been conducted regarding the performance assessment of bridges and the concept of performance indicator has been introduced However, there are still significant discrepancies in how these indicators are obtained and used. Simultaneously, it is desirable to achieve processes and methods that are direct, i.e. that measured values are directly compared with projected values over time. This project concerns methods for verification of technical performance requirements. The feasibility study brought together interdisciplinary researchers, consultants, and entrepreneurs to gather knowledge, anchor the research agenda, and implement performance requirements. The project concludes that there is a need for a “Holistic multi-parameter verification/validation system” that relies on the knowledge gained in structural health monitoring research
Process for verification of performance requirements for transport infrastructure
In recent years, significant worldwide research has been conducted regarding the performance assessment of bridges and the concept of performance indicator has been introduced However, there are still significant discrepancies in how these indicators are obtained and used. Simultaneously, it is desirable to achieve processes and methods that are direct, i.e. that measured values are directly compared with projected values over time. This project concerns methods for verification of technical performance requirements. The feasibility study brought together interdisciplinary researchers, consultants, and entrepreneurs to gather knowledge, anchor the research agenda, and implement performance requirements. The project concludes that there is a need for a “Holistic multi-parameter verification/validation system” that relies on the knowledge gained in structural health monitoring research
CYBERBRIDGE: AN INTERACTIVE TOOL TO PROMOTE ACTIVE LEARNING IN STRUCTURAL ENGINEERING COURSES
Understanding basic concepts and assumptions is a crucial step in the learning process of any subject, yet today it is not always achieved. A change of the current teaching method is suggested in this paper through the implementation of new learning activities based on digital tools. The use of interactive tools has been shown to be an effective method in the field of medicine. Although less frequent, interactive tools could also be beneficial in the field of civil engineering, particularly in structural engineering, where real lab experiments are large, costly and time consuming. By building a small-scale interactive bridge model, the students can have access to a live experiment in the classroom, which enables them to put in practice the concepts learnt during the lectures. This tool seeks promoting a deeper understanding of the subject, thereby increasing the ability of the students to describe different concepts and explain the physical meaning behind the analytical equations taught in structural engineering courses
- …