scholarly journals PREDICTING THE RELIABILITY OF A TUBING STRING DURING OPERATION A PULSED DOWNHOLE DEVICE

2019 ◽  
pp. 79-86
Author(s):  
M. Ya. Khabibullin ◽  
I. G. Arslanov ◽  
R. I. Suleymanov
Keyword(s):  
Boundary Conditions ◽  
Fluid Motion ◽  
Fluid Pressure ◽  
Classical Equation ◽  
Homogeneous System ◽  
Fluid Injection ◽  
Hydraulic Impact ◽  
Tubing String ◽  
Arbitrary Section ◽  
Unsteady Fluid

To study the unsteady fluid motion in a tubing string, when it is pumped, the classical equation of hydraulic impact is solved at the first stage. The solution was carried out by separating the variables taking into account all real initial and boundary conditions. The problem of distributing the hydraulic impact of a viscous liquid in a tubing string from the operation of impulse devices at the bottom of a well as a homogeneous system in which all processes occurring during fluid injection are interrelated. As a result, expressions were obtained for determining the velocity of the fluid and the amplitude of the change in the fluid pressure in any arbitrary section of the liquid column inside the tubing string, over which graphical dependencies are plotted in relative values for different pipe diameters. The results obtained make it possible to predict the reliability of the pipe string for pulsed non-stationary injection of liquid under pressure.

scholarly journals Heat Induction by Viscous Dissipation Subjected to Symmetric and Asymmetric Boundary Conditions on a Small Oscillating Flow in a Microchannel

Symmetry ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 499 ◽  
Author(s):  
Chih Tso ◽  
Chee Hor ◽  
Gooi Chen ◽  
Chee Kok
Keyword(s):  
Temperature Field ◽  
Prandtl Number ◽  
Boundary Conditions ◽  
Viscous Dissipation ◽  
Fluid Velocity ◽  
Fluid Motion ◽  
Lower Plate ◽  
Brinkman Number ◽  
Energy Equations ◽  
Oscillation Rate

The heat induced by viscous dissipation in a microchannel fluid, due to a small oscillating motion of the lower plate, is investigated for the first time. The methodology is by applying the momentum and energy equations and solving them for three cases of standard thermal boundary conditions. The first two cases involve symmetric boundary conditions of constant surface temperature on both plates and both plates insulated, respectively. The third case has the asymmetric conditions that the lower plate is insulated while the upper plate is maintained at constant temperature. Results reveal that, although the fluid velocity is only depending on the oscillation rate of the plate, the temperature field for all three cases show that the induced heating is dependent on the oscillation rate of the plate, but strongly dependent on the parameters Brinkman number and Prandtl number. All three cases prove that the increasing oscillation rate or Brinkman number and decreasing Prandtl number, when it is less than unity, will significantly increase the temperature field. The present model is applied to the synovial fluid motion in artificial hip implant and results in heat induced by viscous dissipation for the second case shows remarkably close agreement with the experimental literature.

On the isometric motion of a charged fluid in the Einstein-Maxwell theory

1974 ◽  
Vol 336 (1606) ◽  
pp. 273-284 ◽  
Keyword(s):  
Killing Vector ◽  
Fluid Motion ◽  
Fluid Pressure ◽  
Field Equations ◽  
Maxwell Theory ◽  
Charged Fluid ◽  
Spherically Symmetric Solution ◽  
Electromagnetic Field Tensor ◽  
Discrete Values ◽  
Full Solution

It is shown that in the Einstein-Maxwell theory a class of four-dimensional charged fluid space-times exists, with non-zero fluid pressure, satisfying the conditions that (i) the fluid motion is isometric, (ii) the dual of the electromagnetic field tensor has no projection in the direction of a Killing vector - equivalent to the condition that in a static space time the local field of an observer moving with the fluid is purely electric - and (iii) the ratio of charge to mass is constant. For the case of a diagonal static metric it is seen that a group of quasi-conformal transformations may be determined which leaves the field equations unchanged. This may be used to obtain a full solution of the field equations, in three independent variables, from a given solution in one independent variable. A spherically symmetric solution of this kind is obtained which is seen to be expressible in terms of hypergeometric functions. An interesting aspect of this is that the charge/mass ratio can only have discrete values depending on the eigenvalues of a linear boundary-value problem.

The role of geomechanical modeling in the measurement and understanding of geophysical data collected during carbon sequestration

2021 ◽  
Vol 40 (6) ◽  
pp. 413-417
Author(s):  
Chunfang Meng ◽  
Michael Fehler
Keyword(s):  
Pore Pressure ◽  
Fault Location ◽  
Mechanical Response ◽  
Fluid Pressure ◽  
Geophysical Data ◽  
Fluid Injection ◽  
Coupled Flow ◽  
Cap Rock ◽  
Stress And Deformation ◽  
Pressure Changes

As fluids are injected into a reservoir, the pore fluid pressure changes in space and time. These changes induce a mechanical response to the reservoir fractures, which in turn induces changes in stress and deformation to the surrounding rock. The changes in stress and associated deformation comprise the geomechanical response of the reservoir to the injection. This response can result in slip along faults and potentially the loss of fluid containment within a reservoir as a result of cap-rock failure. It is important to recognize that the slip along faults does not occur only due to the changes in pore pressure at the fault location; it can also be a response to poroelastic changes in stress located away from the region where pore pressure itself changes. Our goal here is to briefly describe some of the concepts of geomechanics and the coupled flow-geomechanical response of the reservoir to fluid injection. We will illustrate some of the concepts with modeling examples that help build our intuition for understanding and predicting possible responses of reservoirs to injection. It is essential to understand and apply these concepts to properly use geomechanical modeling to design geophysical acquisition geometries and to properly interpret the geophysical data acquired during fluid injection.

scholarly journals Experimental and Numerical Vibration Analysis of Hydraulic Pipeline System under Multiexcitations

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Peixin Gao ◽  
Hongquan Qu ◽  
Yuanlin Zhang ◽  
Tao Yu ◽  
Jingyu Zhai
Keyword(s):  
Pressure Fluctuations ◽  
Fluid Motion ◽  
Fluid Pressure ◽  
Point Of View ◽  
Pipeline System ◽  
Base Excitation ◽  
Fem Method ◽  
Pipeline Systems ◽  
Pump Pressure ◽  
Improved Model

Pipeline systems in aircraft are subjected to both hydraulic pump pressure fluctuations and base excitation from the engine. This can cause fatigue failures due to excessive vibrations. Therefore, it is essential to investigate the vibration behavior of the pipeline system under multiexcitations. In this paper, experiments have been conducted to describe the hydraulic pipeline systems, in which fluid pressure excitation in pipeline is driven by the throttle valve, and the base excitation is produced by the shaker driven by a vibration controller. An improved model which includes fluid motion and base excitation is proposed. A numerical MOC-FEM approach which combined the coupling method of characteristics (MOC) and finite element method (FEM) is proposed to solve the equations. The results show that the current MOC-FEM method could predict the vibration characteristics of the pipeline with sufficient accuracy. Moreover, the pipeline under multiexcitations could produce an interesting beat phenomenon, and this dangerous phenomenon is investigated for its consequences from engineering point of view.

High Resolution DCE-MRI Vascular Characterization of Murine Sarcoma and Human Renal Cell Carcinoma for Computational Modeling

2008 ◽  
Author(s):  
Gregory L. Pishko ◽  
Garrett W. Astary ◽  
Thomas H. Mareci ◽  
Malisa Sarntinoranont
Keyword(s):  
Interstitial Fluid ◽  
Tumor Tissue ◽  
Fluid Motion ◽  
Fluid Pressure ◽  
Bulk Fluid ◽  
Human Renal Cell Carcinoma ◽  
Dce Mri ◽  
Heterogeneous Tissue ◽  
Murine Sarcoma

Non-uniform extravasation from blood vessels, elevated interstitial fluid pressure (IFP), and transport by bulk fluid motion in the extracellular space have all been determined to contribute to the non-uniform tissue distribution of systemically delivered agents in solid tumors. The aforementioned factors can lead to inadequate and uneven uptake in tumor tissue which has been shown to be a major obstacle to macromolecules in clinical cancer therapy [1]. Recently developed computational tumor models have described blood flow either in a single vessel or capillary network with variations in space and time [2]. These studies do not account for heterogeneous tissue transport properties in regions of leakier vessels [3].

Microscopic Slip Boundary Conditions in Unsteady Fluid Flows

2019 ◽  
Vol 123 (26) ◽  
Author(s):  
J. A. de la Torre ◽  
D. Duque-Zumajo ◽  
D. Camargo ◽  
Pep Español
Keyword(s):  
Boundary Conditions ◽  
Fluid Flows ◽  
Slip Boundary Conditions ◽  
Slip Boundary ◽  
Unsteady Fluid

scholarly journals WAVE INTERCEPTION BY SEA-BALLOON BREAKWATER

1986 ◽  
Vol 1 (20) ◽  
pp. 173 ◽  
Author(s):  
Takahiko Uwatoko ◽  
Takeshi Ijima ◽  
Yukimitsu Ushifusa ◽  
Haruyuki Kojima
Keyword(s):  
Incident Wave ◽  
Fluid Motion ◽  
Fluid Pressure ◽  
Vertical Axis ◽  
Boundary Integral ◽  
Long Waves ◽  
Boundary Integral Method ◽  
Wave Crest ◽  
Airflow Resistance ◽  
Incident Waves

When a submerged, flexible bag is filled with air about 60~T0 % of its full volume ( it is called " sea-balloon " ), it has a stable shape with vertical axis of symmetry, on which several vertical wrinkles appear with folds of membrane. If two or more such sea-balloons are arranged to the direction of wave travel and connected pneumatically, balloons are deformed periodically and the air flows reciprocally in connecting pipe, following to the fluid pressure fluctuation due to incident waves. Such a system of sea-balloon intercepts incident waves effectively ( it is called " sea-balloon breakwater "). The wave interception by the breakwater is analyzed numerically by three-dimensional boundary integral method, assuming that the fluid motions both in- and out-side of the balloon are potential and that the tension in balloon membrane is proportional to the apparent elongation of membrane with virtual elastic constant. After analysis and experiments, it is made clear that in relatively long waves the incident wave is canceled by the radiation wave which is generated by volumetric change of sea-balloons, being affected by airflow resistance in connecting pipe. In short waves, sea-balloons seem to behave like as rigid piles and the incident wave is absorbed by airflow resistance in pipe and by the turbulence of fluid motion around balloons. Moreover, the effect of gaps between sea-balloons along wave crest on wave interception for relatively long waves is expressed by a simple empirical formula, by which the transmission coefficients at various types of sea-balloon breakwater is easily estimated by twodimensional computation. For the improvement of wave interception effect and from the point of practical use, the effects of other sea-balloon breakwater system are investigated by two-dimensional computation and experiments.

scholarly journals 4D Travel-Time Tomography as a Tool for Tracking Fluid-Driven Medium Changes in Offshore Oil–Gas Exploitation Areas

Energies ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5878
Author(s):  
Grazia De Landro ◽  
Ortensia Amoroso ◽  
Guido Russo ◽  
Aldo Zollo
Keyword(s):  
Seismic Velocity ◽  
Fluid Pressure ◽  
Time Lapse ◽  
Velocity Model ◽  
Target Volume ◽  
Fluid Injection ◽  
Pressure Perturbation ◽  
Operational Conditions ◽  
Starting Point ◽  
Velocity Changes

The monitoring of rock volume where offshore exploitation activities take place is crucial to assess the corresponding seismic hazard. Fluid injection/extraction operations generate a pore fluid pressure perturbation into the volume hosting the reservoir which, in turn, may trigger new failures and induce changes in the elastic properties of rocks. Our purpose is to evaluate the feasibility of reconstructing pore pressure perturbation diffusion in the host medium by imaging the 4D velocity changes using active seismic. We simulated repeated active offshore surveys and imaged the target volume. We constructed the velocity model perturbed by the fluid injection using physical modeling and evaluated under which conditions the repeated surveys could image the velocity changes. We found that the induced pressure perturbation causes seismic velocity variations ranging between 2–5% and 15–20%, depending on the different injection conditions and medium properties. So, in most cases, time-lapse tomography is very efficient in tracking the perturbation. The noise level characterizing the recording station sites is a crucial parameter. Since we evaluated the feasibility of the proposed 4D imaging strategy under different realistic environmental and operational conditions, our results can be directly applied to set up and configure the acquisition layout of surveys aimed at retrieving fluid-induced medium changes in the hosting medium. Moreover, our results can be considered as a useful starting point to design the guidelines to monitor exploitation areas.

scholarly journals Effective slip boundary conditions for arbitrary periodic surfaces: the surface mobility tensor

2010 ◽  
Vol 658 ◽  
pp. 409-437 ◽  
Author(s):  
KEN KAMRIN ◽  
MARTIN Z. BAZANT ◽  
HOWARD A. STONE
Keyword(s):  
Boundary Conditions ◽  
Fluid Motion ◽  
Patterned Surfaces ◽  
Random Surface ◽  
Slip Boundary ◽  
Surface Mobility ◽  
Mobility Tensor ◽  
Effective Slip ◽  
Mobility Matrix ◽  
Optimal Surface

In a variety of applications, most notably microfluidics design, slip-based boundary conditions have been sought to characterize fluid flow over patterned surfaces. We focus on laminar shear flows over surfaces with periodic height fluctuations and/or fluctuating Navier scalar slip properties. We derive a general formula for the ‘effective slip’, which describes equivalent fluid motion at the mean surface as depicted by the linear velocity profile that arises far from it. We show that the slip and the applied stress are related linearly through a tensorial mobility matrix, and the method of domain perturbation is then used to derive an approximate formula for the mobility law directly in terms of surface properties. The specific accuracy of the approximation is detailed, and the mobility relation is then utilized to address several questions, such as the determination of optimal surface shapes and the effect of random surface fluctuations on fluid slip.

scholarly journals Unsteady Fluid Motion Between Two Infinite Walls Under Variable Body Force

2002 ◽  
Author(s):  
Rostislav Lemdiasov ◽  
Valeriy Tenishev ◽  
Alexander Fedoseyev
Keyword(s):  
Body Force ◽  
Fluid Motion ◽  
Unsteady Fluid
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