3D Modeling of Stability of Mobile Jack-Up Rigs Under Seismic Impacts

2021 ◽  
Author(s):  
Ivan Alekseevich Vasilev ◽  
Nikita Vladislavovich Dubinya ◽  
Viktor Andreevich Nachev ◽  
Dmitry Aleksandrovich Alekseev ◽  
Sergey Andreevich Tikhotskiy
Keyword(s):  
Seismic Waves ◽  
Operating Mode ◽  
Stability Loss ◽  
External Effects ◽  
Field Development ◽  
External Influences ◽  
Geodynamic Processes ◽  
The Stability ◽  
Drilling Rigs ◽  
Jack Up

Abstract The work is devoted to the study of the influence of external mechanical impacts on the stability of jack-up floating drilling rigs. Ensuring safety when working on jack-up floating drilling rigs (jack-up rigs) is one of the most important tasks at the initial stages of offshore hydrocarbon field development. The aim of the work is simulation of the stability of the rigs, which is in the operating mode, both in the absence of external effects acting on it, and when it is affected by various geodynamic processes. Calculation of jack-up rig stability in sea soil with complex viscoelastoplastic rheology under external mechanical influences was carried out using the finite element method. As a result of the work, the spatial distributions of stress and strain fields were determined both in the jack-up rig itself and in the area of the soil in the vicinity of its supports, in an equilibrium and disturbed state. The results of equilibrium static calculations made it possible to analyze the zones of localization of stresses and deformations in the jack-up rig with respect to stability: the structural elements that are most dangerous from the perspective of stability loss were identified. The analysis of the soil area in the vicinity of the jack-up rig supports made it possible to estimate the typical dimensions of the stress concentration zones arising during the jack-up installation and draw conclusions about the requirements on details and scalability of the model of mechanical properties needed for geomechanical modeling at specific objects. The obtained results of dynamic calculations - the response of theconsidered system to external influences simulating remote seismic processes - made it possible to study the process of loss of jack-up rig stability. The critical values of the parameters describing external influences were determined: in particular, the amplitudes of surface seismic waves leading to the loss of stability of the jack-up rig were found. The obtained results made it possible to formulate an algorithm for predicting seismic hazard during drilling in offshore conditions, based on numerical modeling of mechanical processes at specific locations.

Predictive estimates of subsidence of the earth’s surface during the development of the Yamburgskoye oil and gas condensate field

2021 ◽  
pp. 9-22
Author(s):  
Yu. V. Vasiliev ◽  
M. S. Mimeev ◽  
D. A. Misyurev
Keyword(s):  
Oil And Gas ◽  
Active Faults ◽  
Physical And Mechanical Properties ◽  
Deformation Model ◽  
Reservoir Pressure ◽  
Gas Reservoirs ◽  
Field Development ◽  
Geodynamic Processes ◽  
Deformation Processes ◽  
The Stability

The production of hydrocarbons is associated with a change in the physical and mechanical properties of oil and gas reservoirs under the influence of rock and reservoir pressures. Deformation of the reservoir due to a drop in reservoir pressure leads to the formation of various natural and man-made geodynamic and geomechanical phenomena, one of which is the formation of a subsidence trough of the earth's surface, which leads to a violation of the stability of field technological objects.In order to ensure geodynamic safety, a set of works is used, which includes analysis of geological and field indicators and geological and tectonic models of the field, interpretation of aerospace photographs, identification of active faults, construction of a predictive model of subsidence of the earth's surface of the field with identification of zones of geodynamic risk.This work was carried out to assess the predicted parameters of rock displacement processes during field development; even insignificant disturbances in the operation of technological equipment caused by deformation processes can cause significant damage.Prediction of rock displacements is possible only on the basis of a reservoir deformation model that adequately reflects the geomechanical and geodynamic processes occurring in the subsoil. The article presents a model of reservoir deformation with a drop in reservoir pressure, describes its numerical implementation, and performs calculations of schemes for typical development conditions.

Central Asia: International Relations As A Factor Of Regional Stability And Integration

2020 ◽  
Vol 02 (10) ◽  
pp. 135-140
Author(s):  
B.O. Berdiyev ◽  
Keyword(s):  
International Relations ◽  
Central Asia ◽  
Interethnic Relations ◽  
Regional Stability ◽  
External Influences ◽  
The Stability

The article is devoted to the issues of interethnic relations in Central Asia, the need for integration and cooperation between states, external influences, information impacts on the peoples of the region, border issues, overpopulation, ethnic issues and their impact on the stability of the region.

scholarly journals Sliding Mode Control and Geometrization Conjecture in Seismic Response

Symmetry ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 353
Author(s):  
Ligia Munteanu ◽  
Dan Dumitriu ◽  
Cornel Brisan ◽  
Mircea Bara ◽  
Veturia Chiroiu ◽  
...  
Keyword(s):  
Sliding Mode Control ◽  
Ricci Flow ◽  
Lyapunov Functions ◽  
Seismic Waves ◽  
Sliding Mode ◽  
Flow Process ◽  
Mode Control ◽  
Finite Period ◽  
The Stability ◽  
Story Building

The purpose of this paper is to study the sliding mode control as a Ricci flow process in the context of a three-story building structure subjected to seismic waves. The stability conditions result from two Lyapunov functions, the first associated with slipping in a finite period of time and the second with convergence of trajectories to the desired state. Simulation results show that the Ricci flow control leads to minimization of the displacements of the floors.

Study on the bearing resistance of axially compressed L-shaped stainless steel core plate wall based on the stability loss

2021 ◽  
Vol 249 ◽  
pp. 113264
Author(s):  
Xing-Ping Shu ◽  
Huai-Bing Wang ◽  
Yi Li ◽  
Zhi-Shen Yuan ◽  
Ke Li
Keyword(s):  
Stainless Steel ◽  
Stability Loss ◽  
Steel Core ◽  
The Stability

scholarly journals Sliding Mode Control and Geometrization Conjecture in Seismology

2021 ◽  
Author(s):  
Ligia Munteanu ◽  
Dan Dumitriu ◽  
Cornel Brisan ◽  
Mircea Bara ◽  
Veturia Chiroiu ◽  
...  
Keyword(s):  
Sliding Mode Control ◽  
Ricci Flow ◽  
Lyapunov Functions ◽  
Seismic Waves ◽  
Sliding Mode ◽  
Flow Process ◽  
Mode Control ◽  
Finite Period ◽  
The Stability ◽  
Story Building

The purpose of this paper is to study the sliding mode control as a Ricci flow process in the context of a three-story building structure subjected to seismic waves. The stability conditions result from two Lyapunov- functions, the first associated with slipping in a finite period of time, and the second with convergence of trajectories to the desired state. Simulation results show that the Ricci flow control leads to the minimization of the displacements of the floors. 3D Ricci solitons projection via a semi-conformal mapping to a surface is also studied.

scholarly journals ALGORITHM AND SOFTWARE FOR CALCULATING THE STABILITY OF THE FORM OF EQUILIBRIUM OF DISCRETE SYSTEMS

2019 ◽  
Vol 13 (3) ◽  
pp. 44-49
Author(s):  
A.A. SHKURUPIY ◽  
A.N. PASCHENKO ◽  
P.B. MYTROFANOV
Keyword(s):  
Discrete Systems ◽  
Stability Loss ◽  
Transcendental Equation ◽  
Loss Of Stability ◽  
Displacement Method ◽  
Software Complex ◽  
Complex Functions ◽  
Transcendental Functions ◽  
The Stability ◽  
Theoretical Mechanics

The paper presents an algorithm for calculating the stability of the form of equilibrium of the first kind of compressed discrete systems by the method of displacements in combination with themethods of iterations and bisection. The use of the displacement method in combination with the iteration and bisection methods makes it possible to effectively determine the minimum critical stress or strain at the first bifurcation and their corresponding form of loss of stability, both for statically determined and statically undetectable systems. This approach, using matrixforms, makes it possible to significantly simplify the calculations of the analytical condition for the loss of stability of compressed discrete systems (the stability loss equation), which has high orders, as well as to construct the form of loss of stability corresponding to a critical load, that is, to solve the problem of loss of stability of equilibrium. The calculation of the compressed discrete system on the stability of the form of equilibrium actually reduces to the solution of the difficultly described nonlinear transcendental equation, which is the equation of loss of stability. The difficulty lies in the absence of an analytical solution of such an equation due to the presence of complex functions of Zhukovsky, which have transcendental functions in their structure. Such solution can be performed only with the use of numerical methods. This algorithm for calculating the loss of equilibrium of the first kind of compressed discrete systems by displacement in combination with the methods of iteration and bisection is implemented in the software complex "Persist" for a PC in Windows OS. The program was approbated and implemented in theeducational process at the Department of Structural and Theoretical Mechanics of the Poltava National Technical Yuri Kondratyuk University during the training of specialists in engineering specialties.

Successful CRI Project for Offshore Abu Dhabi Field: 3 Million Barrels Injected with ZERO Subsurface Failures

2021 ◽  
Author(s):  
Osama EL Helali ◽  
Mohamed Haddad ◽  
Salamat Gumarov ◽  
Said Benelkadi ◽  
Eduardo Bianco ◽  
...  
Keyword(s):  
Waste Management ◽  
Cost Effective ◽  
Abu Dhabi ◽  
Successful Operation ◽  
Knowledge Based ◽  
Drilling Waste ◽  
Injection Zone ◽  
Challenging Environment ◽  
Drilling Rigs ◽  
Jack Up

Abstract Cuttings reinjection (CRI) project at OFFSHORE ABU DHABI field achieved successful operation with three million barrels injected to date with zero subsurface failures setting up an environmentally friendly and cost-effective waste management success story that complies with zero discharge requirements. The project exceeded initial expectations by accommodating non-aqueous drilling waste from jack-up drilling rigs in addition to artificial islands own rigs. Subsurface assurance and engineering workflows proved to be effective in ensuring subsurface containment of drilling waste in challenging environment while ensuring efficiency of operation to meet demanding drilling schedules. Injection schedules and procedures were based on results of thorough subsurface FEED study and global best practices. Slurry fluid quality requirements were verified thru extensive laboratory tests. Throughout injection operation downhole pressure and temperature of the injection well was vigilantly monitored and analyzed along with well temperature survey and periodic fracture modeling updates of the fracture waste domain to ensure seamless fracturing of formation and containment of waste domain within selected formation. More than 3 million barrels of drill cuttings and associated drilling waste have been safely and successfully disposed of into a single injection zone of two cuttings reinjection wells over five years of project operation to date. No downtime was experienced and no impact to drilling schedule was induced demonstrating high capability of technology when designed and executed in right way. Results of actual injections showed accuracy and robustness of the engineering workflow implemented from Job design, planning and execution The paper presents unique and knowledge-based steps that contributed to success of project and set high bar for region for the drilling waste management.

scholarly journals Assessment of parting rock weak zones under the joint and downward mining of coal seams

2018 ◽  
Vol 66 ◽  
pp. 03001 ◽  
Author(s):  
Volodymyr Bondarenko ◽  
Iryna Kovalevska ◽  
Hennadii Symanovych ◽  
Mykhailo Barabash ◽  
Vasyl Snihur
Keyword(s):  
Stress Component ◽  
Stability Loss ◽  
Coal Seams ◽  
Security Systems ◽  
Relationship Patterns ◽  
Instrumental Observations ◽  
Set Up ◽  
The Stability ◽  
The Relationship ◽  
Weak Zones

The aim of the forecasting effort is to identify troublesome zones of stability loss by a parting lengthwise of the extraction panel under the joint and downward mining of coal seams. Analyses have been carried out of active stress component curves for a 3-D model computational experiment compared with the strength characteristic of each lithotype of a parting. An algorithm has been developed for the stability assessment of a parting lengthwise along the extraction panel. The relationship patterns have been estimated between the sizes of the parting rocks discontinuity zones and the main geomechanical parameters. A scientifically grounded basis has been created for the detection of the parting rock weak zones lengthwise along the extraction panel for the calculation of the mounting and security systems of the development works. A complex of underground instrumental observations was made, which was used to set up a correspondence of patterns to indicate the variation in rock pressure manifestation intensity and the tendencies for changes in the parting structure. All of this confirms the adequacy of the techniques for parting state forecasting, which is recommended for use in the engineering documentation for the joint and downward mining of coal seams.

Domains and Types of Aeroelastic Instability of Slender Beam

2007 ◽  
Author(s):  
Jirˇi´ Na´prstek
Keyword(s):  
Stability Boundary ◽  
Stability Loss ◽  
Stability Domain ◽  
Theoretical Explanation ◽  
Point Of View ◽  
System Response ◽  
Physical Point ◽  
Model Response ◽  
Gyroscopic Forces ◽  
The Stability

Slender structures exposed to a cross air flow are prone to vibrations of several types resulting from aeroelastic interaction of a flowing medium and a moving structure. Aeroelastic forces are the origin of nonconservative and gyroscopic forces influencing the stability of a system response. Conditions of a dynamic stability loss and a detailed analysis of a stability domain has been done using a linear mathematical model. Response properties of a system located on a stability boundary together with tendencies in its neighborhood are presented and interpreted from physical point of view. Results can be used for an explanation of several effects observed experimentally but remaining without theoretical explanation until now.

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