A Simplified Gas-Liquid Flow Model for Kick Mitigation and Control During Drilling Operations

2015 ◽  
Author(s):  
Ulf Jakob F. Aarsnes ◽  
Adrian Ambrus ◽  
Ali Karimi Vajargah ◽  
Ole Morten Aamo ◽  
Eric van Oort
Keyword(s):  
Real Time ◽  
Time Estimation ◽  
Pressure Profile ◽  
Recursive Least Squares ◽  
Model Parameters ◽  
Two Phase ◽  
Hyperbolic Pde ◽  
Phase Dynamics ◽  
First Order ◽  
And Control

Real-time estimation of annular pressure profile and formation pressure is crucial for the execution and planning of a well control operation, especially when drilling formations with narrow pore and fracture pressure margins. A simple transient multi-phase simulator, capable of accurately representing gas and liquid dynamics while minimizing complexity and computational requirements, is highly desirable for real-time kick mitigation and control applications. Such a simulator is presented here in the form of a coupled ODE-PDE model composed of a first order ODE and a first order hyperbolic PDE. This model is shown to retain the dominating two-phase dynamics encountered during gas kick incidents. As a particular application, we demonstrate the use of the model in design of switched control algorithms for kick handling in a Managed Pressure Drilling setting. A Recursive Least Squares algorithm is employed for estimation of unknown model parameters.

scholarly journals Joint structure for the real-time estimation and control of automotive dry clutch engagement

2018 ◽  
Vol 51 (15) ◽  
pp. 1062-1067 ◽  
Author(s):  
Mojtaba Sharifzadeh ◽  
Mario Pisaturo ◽  
Arash Farnam ◽  
Adolfo Senatore
Keyword(s):  
Real Time ◽  
Time Estimation ◽  
The Real ◽  
Joint Structure ◽  
Clutch Engagement ◽  
Real Time Estimation ◽  
Dry Clutch ◽  
Estimation And Control ◽  
And Control

scholarly journals Generalized second-order slip for unsteady convective flow of a nanofluid: a utilization of Buongiorno’s two-component nonhomogeneous equilibrium model

2020 ◽  
Vol 9 (1) ◽  
pp. 156-168
Author(s):  
Seyed Mahdi Mousavi ◽  
Saeed Dinarvand ◽  
Mohammad Eftekhari Yazdi
Keyword(s):  
Boundary Layer ◽  
Equilibrium Model ◽  
Second Order ◽  
Model Parameters ◽  
Slip Parameter ◽  
Two Phase ◽  
Convective Boundary ◽  
First Order ◽  
Special Cases ◽  
Two Component

AbstractThe unsteady convective boundary layer flow of a nanofluid along a permeable shrinking/stretching plate under suction and second-order slip effects has been developed. Buongiorno’s two-component nonhomogeneous equilibrium model is implemented to take the effects of Brownian motion and thermophoresis into consideration. It can be emphasized that, our two-phase nanofluid model along with slip concentration at the wall shows better physical aspects relative to taking the constant volume concentration at the wall. The similarity transformation method (STM), allows us to reducing nonlinear governing PDEs to nonlinear dimensionless ODEs, before being solved numerically by employing the Keller-box method (KBM). The graphical results portray the effects of model parameters on boundary layer behavior. Moreover, results validation has been demonstrated as the skin friction and the reduced Nusselt number. We understand shrinking plate case is a key factor affecting non-uniqueness of the solutions and the range of the shrinking parameter for which the solution exists, increases with the first order slip parameter, the absolute value of the second order slip parameter as well as the transpiration rate parameter. Besides, the second-order slip at the interface decreases the rate of heat transfer in a nanofluid. Finally, the analysis for no-slip and first-order slip boundary conditions can also be retrieved as special cases of the present model.

scholarly journals Adaptive and Personalized Plasma Insulin Concentration Estimation for Artificial Pancreas Systems

2018 ◽  
Vol 12 (3) ◽  
pp. 639-649 ◽  
Author(s):  
Iman Hajizadeh ◽  
Mudassir Rashid ◽  
Sediqeh Samadi ◽  
Jianyuan Feng ◽  
Mert Sevil ◽  
...  
Keyword(s):  
Real Time ◽  
Plasma Insulin ◽  
Artificial Pancreas ◽  
Time Estimation ◽  
The Body ◽  
Insulin Concentration ◽  
Model Parameters ◽  
Plasma Insulin Concentration ◽  
Real Time Estimation ◽  
Clinical Experiments

Background: The artificial pancreas (AP) system, a technology that automatically administers exogenous insulin in people with type 1 diabetes mellitus (T1DM) to regulate their blood glucose concentrations, necessitates the estimation of the amount of active insulin already present in the body to avoid overdosing. Method: An adaptive and personalized plasma insulin concentration (PIC) estimator is designed in this work to accurately quantify the insulin present in the bloodstream. The proposed PIC estimation approach incorporates Hovorka’s glucose-insulin model with the unscented Kalman filtering algorithm. Methods for the personalized initialization of the time-varying model parameters to individual patients for improved estimator convergence are developed. Data from 20 three-days-long closed-loop clinical experiments conducted involving subjects with T1DM are used to evaluate the proposed PIC estimation approach. Results: The proposed methods are applied to the clinical data containing significant disturbances, such as unannounced meals and exercise, and the results demonstrate the accurate real-time estimation of the PIC with the root mean square error of 7.15 and 9.25 mU/L for the optimization-based fitted parameters and partial least squares regression-based testing parameters, respectively. Conclusions: The accurate real-time estimation of PIC will benefit the AP systems by preventing overdelivery of insulin when significant insulin is present in the bloodstream.

Real-Time Self-Tuning Speed Controller: Performance Comparison between Engine Fuelled with Palm Methyl Esters and Petroleum Diesel

2015 ◽  
Vol 815 ◽  
pp. 408-412
Author(s):  
M.N. Azuwir ◽  
Mohd Sazli Saad ◽  
Mohd Zakimi Zakaria
Keyword(s):  
Real Time ◽  
Least Squares Method ◽  
Methyl Esters ◽  
Performance Comparison ◽  
Parameters Estimation ◽  
Recursive Least Squares ◽  
Model Parameters ◽  
Automotive Engine ◽  
Speed Controller ◽  
Self Tuning

This paper investigates the performance of a real-time self-tuning speed controller designed to track and regulate at various engine speeds. The controller was tested with an automotive engine fuelled with petroleum diesel and and palm oil biodiesel (Palm Methyl Esters) within speed range of 1800 rpm to 2400 rpm. A self-tuning control algorithm based on pole assignment method together with on-line model parameters estimation strategy based on the recursive least squares method are adopted. The ability of the controller to track, regulate at various engine speed and also to reject disturbances applied for both type of fuel are compared and presented. The results confirmed that the controller performed very satisfactorily.

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