Overcoming Wellbore Instability Challenges in HPHT Field with Fully Coupled Poro-Thermo-Elastic Modeling: A Case Study in Hai Thach Field Offshore Vietnam

2016 ◽  
Author(s):  
Son K. Hoang ◽  
Son T. Nguyen ◽  
Giang H. Khuc ◽  
Duc A. Nguyen ◽  
Younane N. Abousleiman
Keyword(s):  
Wellbore Instability ◽  
Fully Coupled

FHS Semi: A Semisubmersible Design for Dry Tree Applications

2009 ◽  
Author(s):  
Alaa M. Mansour
Keyword(s):  
Gulf Of Mexico ◽  
Water Depth ◽  
Time Domain ◽  
Frequency Range ◽  
Integration Technique ◽  
Natural Period ◽  
Ballast Tank ◽  
New Feature ◽  
Fully Coupled

In this paper the performance of a new conceptual semisubmersible design that provides motion response similar to a Spar is investigated. The new invention introduces a new feature which is the Free-Hanging Solid Ballast Tank, hence the name FHS Semi. The use of the free-hanging Solid Ballast Tank (SBT) significantly increases the heave natural period while controlling the heave response in the wave frequency range and, therefore, enables the use of the FHS Semi in dry tree applications. The new design’s quayside integration technique and its interface with the top tensioned risers are presented in this paper. Case study for the new design to support a 32,000 ST payload including 15 Top Tensioned Risers (TTRs) in an ultra-deepwater of 8,000 ft water depth is considered. Frequency domain and fully coupled time-domain hydrodynamic analyses have been performed and numerical results are presented to illustrate the new semisubmersible design response in extreme Gulf of Mexico hurricane events.

Modelling aerosol–cloud–meteorology interaction: A case study with a fully coupled air quality model (GEM-MACH)

2015 ◽  
Vol 115 ◽  
pp. 695-715 ◽  
Author(s):  
W. Gong ◽  
P.A. Makar ◽  
J. Zhang ◽  
J. Milbrandt ◽  
S. Gravel ◽  
...  
Keyword(s):  
Air Quality ◽  
Air Quality Model ◽  
Quality Model ◽  
Aerosol Cloud ◽  
Fully Coupled

ON IMPLEMENTATION AND PERFORMANCE OF AN ANISOTROPIC CONSTITUTIVE MODEL FOR CLAYS

2014 ◽  
Vol 11 (02) ◽  
pp. 1342009 ◽  
Author(s):  
MAJID T. MANZARI ◽  
KARMA YONTEN
Keyword(s):  
Constitutive Model ◽  
Pore Pressure ◽  
Field Measurements ◽  
Ground Settlement ◽  
Element Analysis ◽  
Foundation Soil ◽  
And Performance ◽  
Fully Coupled ◽  
Anisotropic Constitutive Model

Numerical implementation of an anisotropic constitutive model for clays (SANICLAY) is presented. Moreover, a case study in which a soil embankment is placed on a K0-consolidated over-consolidated clay is analyzed by conducting an elastoplastic fully-coupled finite element analysis. It is shown that anisotropy has significant impact on the ground settlement caused by the placement of soil embankment and on the pore pressure generation and dissipation within the foundation soil. The simulations using SANICLAY favorably compare with the field measurements of ground settlement and pore pressure. The drawbacks of the use of an isotropic elastoplastic model (Cam Clay) are also demonstrated.

scholarly journals Study on the Surge-Swab Pressure considering the Effect of the Cutting Plug in Shale Drilling

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
Tianyi Tan ◽  
Hui Zhang ◽  
Xusheng Ma ◽  
Yufei Chen
Keyword(s):  
Horizontal Wells ◽  
Wellbore Stability ◽  
Pressure Management ◽  
Accurate Calculation ◽  
Wellbore Instability ◽  
Wellbore Pressure ◽  
The Difference ◽  
Open Pipe ◽  
Frequent Problem

Wellbore instability is a frequent problem of shale drilling. Accurate calculation of surge-swab pressures in tripping processes is essential for wellbore pressure management to maintain wellbore stability. However, cutting plugs formed in shale horizontal wells have not been considered in previous surge-swab pressure models. In this paper, a surge-swab pressure model considering the effect of cutting plugs is established for both open pipe string and closed pipe string conditions; In this model, the osmotic pressure of a cutting plug is analyzed. The reduction of cutting plug porosity due to shale hydration expansion and dispersion is considered, ultimately resulting in an impermeable cutting plug. A case study is conducted to analyze swab pressures in a tripping out process. The results show that, in a closed pipe condition, the cutting plug significantly increases the swab pressures below it, which increase with the decrease of cutting plug porosity and the increase of cutting plug length. Under the give condition, the swab pressure at the bottom of the well increases from 3.60 MPa to 8.82 MPa due to the cutting plug, increasing by 244.9%. In an open pipe string condition, the cutting plug affects the flow rate in the pipes and the annulus, resulting in a higher swab pressure above the cutting plug compared to a no-cutting plug annulus. The difference increases with the decrease of the porosity and the increase of the length and the measured depth of the cutting plug. Consequently, the extra surge-swab pressures caused by cutting plugs could result in wellbore pressures out of safety mud density window, whereas are ignored by previous models. The model proposes a more accurate wellbore pressure prediction and guarantees the wellbore stability in shale drilling.

scholarly journals A Marine Turbocharger Retrofitting Platform

2020 ◽  
Author(s):  
Konstantinos Ntonas ◽  
Nikolaos Aretakis ◽  
Ioannis Roumeliotis ◽  
Konstantinos Mathioudakis
Keyword(s):  
Diesel Engine ◽  
Engine Performance ◽  
Optimization Procedure ◽  
Engine Efficiency ◽  
Performance Trends ◽  
Second Mode ◽  
Coupled Process ◽  
The One ◽  
Fully Coupled

Abstract A turbocharger retrofitting platform utilizing 1D models for calculating turbomachinery components maps and a fully coupled process for integration with the turbomachinery components and the diesel engine, is presented. The platform has been developed with two modes of operation, allowing the retrofitting process to become fully automatic. In the first mode, available turbo-components are examined, in order to select the one that best matches the entire engine system, aiming to retain or improve the diesel engine efficiency. In the second mode, an optimization procedure is employed, in order to redesign the compressor to match the entire system in an optimum way. Dimensionless parameters are used as optimization variables, for a given compressor mass flow and power. A retrofitting case study is presented, where three retrofitting options are analyzed (compressor retrofit, turbocharger retrofit and compressor redesign). In the first and second option, turbocharger retrofitting is carried out, using available turbo-components. It is shown that initial performance cannot be reconstituted using off-the-self solutions. In the third option, compressor designing is performed, using the optimization mode, in order to provide an improved retrofitting solution, aiming to at least reconstituting the original diesel engine performance. Finally, a CFD analysis is carried out, in order to validate the compressor optimization tool capability to capture the performance trends, based on geometry variation.

Water Hammer (With FSI): Exact Solution — Parallelization and Application

2014 ◽  
Author(s):  
Kelvin Loh ◽  
Arris S. Tijsseling
Keyword(s):  
Exact Solution ◽  
Water Hammer ◽  
Structural Behaviour ◽  
Internal Fluid ◽  
Optimal Damping ◽  
Fluid Transients ◽  
Simple Recursion ◽  
Water Hammer Effect ◽  
Fully Coupled

The 1D fully coupled Fluid-Structure Interaction (FSI) model can adequately describe the water hammer effect on the fluid, and the structural behaviour of the pipe. This paper attempts to increase the capability of using an exact solution of the 1D FSI problem applied to a straight pipe with a valve. The work builds upon a simple recursion algorithm to obtain exact solutions. This paper describes the attempts to parallelize the time-consuming algorithm and presents an optimization case study. The algorithm has been parallelized using a Master-Slave MPI model for scalability. The applicability of this all has been explored by an optimization case study, which seeks the optimal damping coefficient of a dashpot connected to the valve to reduce the structural stresses in the pipe wall and the pressure in the fluid. Thus, an external damper is used to mitigate internal fluid transients.

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