scholarly journals Optimal Simulation and Mathematical Correlation of Mud Weight for Effective Wellbore Stability Management

2020 ◽  
Vol 5 (1) ◽  
pp. 96-99
Author(s):  
Boniface A. Oriji ◽  
Raphael Odikpo Okeke
Keyword(s):  
Mass Flow ◽  
Total Mass ◽  
Input Data ◽  
Wellbore Stability ◽  
Liquid Density ◽  
Fluid Temperature ◽  
Gas Density ◽  
Data Points ◽  
Residual Values ◽  
The Impact

Wellbore instability is a problem that affects drilling activities. It is therefore important to provide an optimal solution that prevents or reduces the occurrence of wellbore collapse and not compromise the integrity of the well. In this study, work was done to assess the impact of several parameters including tubing pressure, tubing fluid temperature, length of tubing, gas density, liquid density, tubing hold-up and total mass flow on mass fraction of tubing muds were considered. Data points for this investigation were obtained using OLGA multiphase simulator. The results of the simulation (including the trend and plot data) were exported to MATLAB to develop a mud weight model (correlation) using the MATLAB regress function. The correlation was also validated using statistical techniques such as the R square and Significance F values. Comparison of the trend plots of the actual data points from OLGA and the predicted data points was also done to further prove the reliability of the correlation. The correlation predictions agreed with the OLGA results excellently with a relative error of less than 0.001 %. This study revealed that the tubing mud weight is significantly impacted on by variables like tubing holdup, tubing gas density, tubing liquid densities and the total mass flow. Whereas the tubing pressure, fluid temperature, and the tubing length have insignificant effects on the tubing mud weight. From the trend plots of the variables, it was deduced that as the tubing pressure increased, the temperature and the mud weight also increased. While, the total mass and volumetric flows reduced with increased tubing pressure. The effect of input data uncertainties on the developed correlation were also tested by using 22 observation points to predict tubing mud weight and calculating the resulting residual values. Over 90% of the residual values were negative and the percentage difference in mud weight between the first and the last observation points was approximately 4%. Hence, the effect of input data uncertainties on the developed correlation is insignificant. This report will serve as a template for drilling engineers, assisting them with a simple, fast and reliable technique for determining optimum drilling parameters with a lesser engineering exertion and drilling experience.

scholarly journals Workflow to build a continuous static elastic moduli profile from the drilling data using artificial intelligence techniques

2021 ◽  
Author(s):  
Osama Siddig ◽  
Salaheldin Elkatatny
Keyword(s):  
Young’S Modulus ◽  
Elastic Moduli ◽  
Young's Modulus ◽  
Correlation Coefficients ◽  
Wellbore Stability ◽  
Machine Learning Techniques ◽  
Support Vector ◽  
Ann Model ◽  
Weight On Bit ◽  
Data Points

AbstractRock mechanical properties play a crucial role in fracturing design, wellbore stability and in situ stresses estimation. Conventionally, there are two ways to estimate Young’s modulus, either by conducting compressional tests on core plug samples or by calculating it from well log parameters. The first method is costly, time-consuming and does not provide a continuous profile. In contrast, the second method provides a continuous profile, however, it requires the availability of acoustic velocities and usually gives estimations that differ from the experimental ones. In this paper, a different approach is proposed based on the drilling operational data such as weight on bit and penetration rate. To investigate this approach, two machine learning techniques were used, artificial neural network (ANN) and support vector machine (SVM). A total of 2288 data points were employed to develop the model, while another 1667 hidden data points were used later to validate the built models. These data cover different types of formations carbonate, sandstone and shale. The two methods used yielded a good match between the measured and predicted Young’s modulus with correlation coefficients above 0.90, and average absolute percentage errors were less than 15%. For instance, the correlation coefficients for ANN ranged between 0.92 and 0.97 for the training and testing data, respectively. A new empirical correlation was developed based on the optimized ANN model that can be used with different datasets. According to these results, the estimation of elastic moduli from drilling parameters is promising and this approach could be investigated for other rock mechanical parameters.

scholarly journals Co-Simulation Framework for Optimal Allocation and Power Management of DGs in Power Distribution Networks Based on Computational Intelligence Techniques

Electronics ◽  
2021 ◽  
Vol 10 (14) ◽  
pp. 1648
Author(s):  
Marinko Barukčić ◽  
Toni Varga ◽  
Vedrana Jerković Jerković Štil ◽  
Tin Benšić
Keyword(s):  
Power System ◽  
Power Management ◽  
Computational Intelligence ◽  
Input Data ◽  
Optimization Problem ◽  
Optimal Allocation ◽  
Distribution Networks ◽  
Distributed Generations ◽  
Data Resolution ◽  
The Impact

The paper researches the impact of the input data resolution on the solution of optimal allocation and power management of controllable and non-controllable renewable energy sources distributed generation in the distribution power system. Computational intelligence techniques and co-simulation approach are used, aiming at more realistic system modeling and solving the complex optimization problem. The optimization problem considers the optimal allocation of all distributed generations and the optimal power control of controllable distributed generations. The co-simulation setup employs a tool for power system analysis and a metaheuristic optimizer to solve the optimization problem. Three different resolutions of input data (generation and load profiles) are used: hourly, daily, and monthly averages over one year. An artificial neural network is used to estimate the optimal output of controllable distributed generations and thus significantly decrease the dimensionality of the optimization problem. The proposed procedure is applied on a 13 node test feeder proposed by the Institute of Electrical and Electronics Engineers. The obtained results show a huge impact of the input data resolution on the optimal allocation of distributed generations. Applying the proposed approach, the energy losses are decreased by over 50–70% by the optimal allocation and control of distributed generations depending on the tested network.

scholarly journals A Person-to-Person and Person-to-Place COVID-19 Contact Tracing System Based on OGC IndoorGML

2020 ◽  
Vol 10 (1) ◽  
pp. 2 ◽  
Author(s):  
Soroush Ojagh ◽  
Sara Saeedi ◽  
Steve H. L. Liang
Keyword(s):  
Data Model ◽  
Low Cost ◽  
Large Body ◽  
Contact Tracing ◽  
Trajectory Data ◽  
Sequential Order ◽  
Human Contact ◽  
Wide Availability ◽  
Data Points ◽  
The Impact

With the wide availability of low-cost proximity sensors, a large body of research focuses on digital person-to-person contact tracing applications that use proximity sensors. In most contact tracing applications, the impact of SARS-CoV-2 spread through touching contaminated surfaces in enclosed places is overlooked. This study is focused on tracing human contact within indoor places using the open OGC IndoorGML standard. This paper proposes a graph-based data model that considers the semantics of indoor locations, time, and users’ contexts in a hierarchical structure. The functionality of the proposed data model is evaluated for a COVID-19 contact tracing application with scalable system architecture. Indoor trajectory preprocessing is enabled by spatial topology to detect and remove semantically invalid real-world trajectory points. Results show that 91.18% percent of semantically invalid indoor trajectory data points are filtered out. Moreover, indoor trajectory data analysis is innovatively empowered by semantic user contexts (e.g., disinfecting activities) extracted from user profiles. In an enhanced contact tracing scenario, considering the disinfecting activities and sequential order of visiting common places outperformed contact tracing results by filtering out unnecessary potential contacts by 44.98 percent. However, the average execution time of person-to-place contact tracing is increased by 58.3%.

Impact of High Resolution 3D Geomechanics on Well Optimization in the Southern Gulf of Suez, Egypt

2021 ◽  
Author(s):  
Mohamed Elkhawaga ◽  
Wael A. Elghaney ◽  
Rajarajan Naidu ◽  
Assef Hussen ◽  
Ramy Rafaat ◽  
...  
Keyword(s):  
High Resolution ◽  
Pore Pressure ◽  
Cost Optimization ◽  
Oil Field ◽  
Wellbore Stability ◽  
Gulf Of Suez ◽  
Geomechanical Model ◽  
3D Geomechanical Model ◽  
The Cost ◽  
The Impact

Abstract Optimizing the number of casing strings has a direct impact on cost of drilling a well. The objective of the case study presented in this paper is the demonstration of reducing cost through integration of data. This paper shows the impact of high-resolution 3D geomechanical modeling on well cost optimization for the GS327 Oil field. The field is located in the Sothern Gulf of Suez basin and has been developed by 20 wells The conventional casing design in the field included three sections. In this mature field, especially with the challenge of reducing production cost, it is imperative to look for opportunites to optimize cost in drilling new wells to sustain ptoduction. 3D geomechanics is crucial for such cases in order to optimize the cost per barrel at the same time help to drill new wells safely. An old wellbore stability study did not support the decision-maker to merge any hole sections. However, there was not geomechanics-related problems recorded during the drilling the drilling of different mud weights. In this study, a 3D geomechanical model was developed and the new mud weight calculations positively affected the casing design for two new wells. The cost optimization will be useful for any future wells to be drilled in this area. This study documents how a 3D geomechanical model helped in the successful delivery of objectives (guided by an understanding of pore pressure and rock properties) through revision of mud weight window calculations that helped in optimizing the casing design and eliminate the need for an intermediate casing. This study reveals that the new calculated pore pressure in the GS327 field is predominantly hydrostatic with a minor decline in the reservoir pressure. In addition, rock strength of the shale is moderately high and nearly homogeneous, which helped in achieving a new casing design for the last two drilled wells in the field.

Numerical Investigation of Local Cooling Enhancement Using Pin-Finned Channel With Incremental Impingement

2017 ◽  
Author(s):  
Susheel Singh ◽  
Sumanta Acharya ◽  
Forrest Ames
Keyword(s):  
Aspect Ratio ◽  
Mass Flow ◽  
Cross Flow ◽  
Surface Cooling ◽  
Local Cooling ◽  
Stagnation Region ◽  
Flow Rates ◽  
Pin Fins ◽  
Mass Flow Rates ◽  
The Impact

Flow and heat transfer in a low aspect ratio pin-finned channel, representative of an internally cooled turbine airfoil, is investigated using Large Eddy Simulations (LES). To achieve greater control of surface cooling distribution, a novel approach has been recently proposed in which coolant is injected incrementally through a series of holes located immediately behind a specially designed cutout region downstream of the pin-fins. Sheltering the coolant injection behind the pin-fins avoids the impact of the cross-flow buildup that deflects the impingement jet and isolates the surface from cooling. The longitudinal and transverse spacing of the pin-fins, arranged in a staggered fashion, is X/D = 1.046 and S/D = 1.625, respectively. The aspect ratio (H/D) of pin-fin channel is 0.5. Due to the presence of the sequential jets in the configuration, the local cooling rates can be controlled by controlling the jet-hole diameter which impacts the jet mass flow rate. Hence, four different hole diameters, denoted as Large (L), Medium (M) , Small (S), Petite (P) are tested for impingement holes, and their effects are studied. Several patterns of the hole-size distributions are studied. It is shown that the peak Nusselt number in the stagnation region below the jet correlates directly with the jet-velocity, while downstream the Nusselt numbers correlate with the total mass flow rates or the average channel velocity. The local cooling parameter defined as (Nu/Nu0)(1-ε) correlates with the jet/channel mass flow rates.

Cooperative activation in cardiac muscle: impact of sarcomere length

2002 ◽  
Vol 282 (3) ◽  
pp. H1055-H1062 ◽  
Author(s):  
David P. Dobesh ◽  
John P. Konhilas ◽  
Pieter P. de Tombe
Keyword(s):  
Sarcomere Length ◽  
Linear Regression Analysis ◽  
Multiple Linear Regression Analysis ◽  
Significant Function ◽  
Cardiac Myofilament ◽  
Data Points ◽  
On Line ◽  
The Impact ◽  
Cooperative Activation ◽  
Force Relationship

This study was undertaken to determine the impact of sarcomere length (SL) on the level of cooperative activation of the cardiac myofilament at physiological [Mg2+]. Active force development was measured in skinned rat cardiac trabeculae as a function of free [Ca2+] at five SLs (1.85–2.25 μm; 1 mM free [Mg2+]; 15°C). Only muscle preparations with minimal force rundown during the entire protocol were included in the analysis (average 7.2 ± 1.7%). Median SL was measured by on-line computer video micrometry and controlled within 0.01 μm. Care was taken to ensure a sufficient number of data points in the steep portion of the [Ca2+]-force relationship at every SL to allow for accurate fit of the data to a modified Hill equation. Multiple linear regression analysis of the fit parameters revealed that both maximum, Ca2+-saturated force and Ca2+sensitivity were a significant function of SL ( P < 0.001), whereas the level of cooperativity did not depend on SL ( P = 0.2). Further analysis of the [Ca2+]-force relationships revealed a marked asymmetry that, also, was not affected by SL ( P = 0.2–0.6). Finally, we found that the level of cooperativity in isolated skinned myocardium was comparable to that reported for intact, nonskinned myocardium. Our results suggest that an increase in SL induces an increase in the Ca2+ responsiveness of the cardiac sarcomere without affecting the level of cooperativity.

Leakage flow analysis in the gas turbine shroud gap

2019 ◽  
Vol 91 (8) ◽  
pp. 1077-1085 ◽  
Author(s):  
Filip Wasilczuk ◽  
Pawel Flaszynski ◽  
Piotr Kaczynski ◽  
Ryszard Szwaba ◽  
Piotr Doerffer ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Gas Turbine ◽  
Mass Flow ◽  
Labyrinth Seal ◽  
Leakage Flow ◽  
Original Design ◽  
Reference Case ◽  
Content Type ◽  
Flow Through ◽  
The Impact

Purpose The purpose of the study is to measure the mass flow in the flow through the labyrinth seal of the gas turbine and compare it to the results of numerical simulation. Moreover the capability of two turbulence models to reflect the phenomenon will be assessed. The studied case will later be used as a reference case for the new, original design of flow control method to limit the leakage flow through the labyrinth seal. Design/methodology/approach Experimental measurements were conducted, measuring the mass flow and the pressure in the model of the labyrinth seal. It was compared to the results of numerical simulation performed in ANSYS/Fluent commercial code for the same geometry. Findings The precise machining of parts was identified as crucial for obtaining correct results in the experiment. The model characteristics were documented, allowing for its future use as the reference case for testing the new labyrinth seal geometry. Experimentally validated numerical model of the flow in the labyrinth seal was developed. Research limitations/implications The research studies the basic case, future research on the case with a new labyrinth seal geometry is planned. Research is conducted on simplified case without rotation and the impact of the turbine main channel. Practical implications Importance of machining accuracy up to 0.01 mm was found to be important for measuring leakage in small gaps and decision making on the optimal configuration selection. Originality/value The research is an important step in the development of original modification of the labyrinth seal, resulting in leakage reduction, by serving as a reference case.

Dynamic vacuum pressure tracking control with high-speed on-off valves

2018 ◽  
Vol 232 (10) ◽  
pp. 1325-1336 ◽  
Author(s):  
Gang Yang ◽  
Kai Chen ◽  
Linglong Du ◽  
Jingmin Du ◽  
Baoren Li
Keyword(s):  
Mass Flow ◽  
Pulse Width ◽  
High Speed ◽  
Pulse Width Modulation ◽  
Sliding Mode ◽  
Tracking System ◽  
Vacuum Pressure ◽  
Chamber Pressure ◽  
Asymmetric Structure ◽  
The Impact

A vacuum pressure tracking system with high-speed on-off valves is a discontinuous system due to the discrete nature of high-speed on-off valves. Chamber pressure changes in the system are determined by the mass flow rates during the processes of charging and discharging. Here, a sliding mode controller with an asymmetric compensator based on average mass flow rate is designed for accurate vacuum pressure tracking. The controller output signal is converted into the duty cycles of the high-speed on-off valves via a pulse width modulation pulsing scheme. Owing to the extreme asymmetry of the processes, an asymmetric structure comprising one high-speed on-off valve in the charging unit and three high-speed on-off valves in the discharging unit is applied to weaken the impact of asymmetry. In addition, an asymmetric compensator is also designed to modify the pulse width modulation pulsing scheme to further eliminate the asymmetry. Experimental results indicate that the proposed controller achieves better performance in pressure tracking with the asymmetric compensator overcoming process asymmetry and enhancing system robustness.

The Impact of Macroeconomic Factors on Environmental Loss Ratio: Evidence from Taiwanese Insurance Data

2018 ◽  
Vol 21 (03) ◽  
pp. 1850020
Author(s):  
Li-Hua Lai ◽  
Ching-Hao Chen ◽  
Tung-Cheng Chang
Keyword(s):  
Input Data ◽  
Economic Loss ◽  
Environmental Condition ◽  
Loss Ratio ◽  
Negative Effects ◽  
Macroeconomic Factors ◽  
Macroeconomic Factor ◽  
Environmental Loss ◽  
The Impact ◽  
Insurance Data

Environmental insurance (EI) protections help resolve the firm-industry economic loss problem. However, the loss ratio of EI is positively affected by itself from one period ahead. The positive and negative effects of macroeconomic factor on the loss ratio of EIs are not necessarily consistent, but they are dependent on the effect of the year’s environmental condition. The economic variables affecting the loss ratio of EI are quite inconsistent, so insurance prices and liability reserves should be modified every year. While the investigations are the special properties of our input data of Taiwan, the prescription of this paper could provide cross-references with other countries.

Nearly free-molecular slit flow at finite pressure and temperature ratios

1971 ◽  
Vol 50 (3) ◽  
pp. 565-577 ◽  
Author(s):  
P. Y. Wang ◽  
E. Y. Yu
Keyword(s):  
Mass Flow ◽  
Total Mass ◽  
Noble Gas ◽  
Order Correction ◽  
Linear Boltzmann Equation ◽  
Molecular Flow ◽  
First Order ◽  
Slit Flow ◽  
Isothermal Case ◽  
First Order Correction

An analytical study is made of nearly free-molecular flow of a noble gas from one reservoir to another through a two-dimensional slit, with finite pressure and temperature ratios across the slit. The fundamental solution of the linear Boltzmann equation is employed in the study. The total mass flow is calculated to the first-order correction terms, of the order of α ln α and α, where α is the inverse Knudsen number. The coefficients of these terms are in general multiple integrals, but they become explicit functions of the pressure and temperature ratios after the multiple integrations are carried out by using Krook collision model. When the general result is simplified to the isothermal case the first-order correction has a negative value, indicating the reduction of the total mass flow due to intermolecular collisions in the counter flows.

Sign in / Sign up

Export Citation Format

Share Document