Experimental Study of Laminar Displacement Flows in Narrow Horizontal Eccentric Annuli

2020 ◽  
Author(s):  
Alondra Renteria ◽  
Yee Voon Liew ◽  
Ian Frigaard
Keyword(s):  
Viscosity Ratio ◽  
High Sensitivity ◽  
Secondary Flows ◽  
Flow Loop ◽  
Fluid Displacement ◽  
Eccentric Annulus ◽  
Model Predictions ◽  
Dimensional Parameters ◽  
Primary Cementing ◽  
Fluid Rheology

Abstract Wells with poor cement jobs are prone to develop paths where the hydrocarbons might leak to the surface. Such events cause environmental risks and costly repairs. Even though horizontal wells have been drilled since the 1980s, studies on the dynamics of the fluid-fluid displacement under this configuration are scarce. In this work, we present experiments on the displacement of two Newtonian fluids in laminar regime in a horizontal uniform annulus. The minimum non-dimensional parameters required to describe the flow under such conditions include a buoyancy number (b), viscosity ratio (μ2/μ1) and eccentricity (e). We have designed and built a flow loop that mimics the annular displacement under controlled and dimensionlessly comparable conditions found in field. Within this apparatus we can set key process parameters: flow rate, eccentricity, fluid rheology and density. Data acquisition is through imaging with high sensitivity cameras and partially automated instrumentation. Preliminary results of the experiments show that there is a subtle balance between eccentricity and buoyancy. Sufficiently high values of |b| will end up in stratification of the fluids. The secondary flows created in an eccentric annulus compete against a positive buoyancy, driving the flow to the wide side (top) at moderate values of b. The effect of the viscosity ratio is most relevant at small values of b. The experimental data from this work can be compared against both mathematical model predictions and computational simulations used in the design of primary cementing jobs.

scholarly journals A Comparative Study of Laminar-Turbulent Displacement in an Eccentric Annulus under Imposed Flow Rate and Imposed Pressure Drop Conditions

Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1654
Author(s):  
Yasaman Foolad ◽  
Majid Bizhani ◽  
Ian A. Frigaard
Keyword(s):  
Horizontal Well ◽  
Fluid Displacement ◽  
Eccentric Annulus ◽  
Time Estimates ◽  
Primary Cementing ◽  
Significant Yield ◽  
Series Of Experiments ◽  
Eccentric Annuli ◽  
High Reynolds ◽  
Operational Constraints

This paper presents a series of experiments focused on the displacement of viscoplastic fluids by various Newtonian and non-Newtonian fluids from a long horizontal, eccentric annulus. The flow regimes range from high Reynolds number laminar regimes through to fully turbulent. These experiments represent the primary cementing operation in a horizontal well. The main objective of our experiments is to gain insight into the role of the flow regime in the fluid-fluid displacement flows of relevance to primary cementing. We study strongly eccentric annuli and displaced fluids with a significant yield stress, i.e., those scenarios where a mud channel is most likely to persist. For fully eccentric annuli, the displacements are uniformly poor, regardless of regime. This improves for an eccentricity of 0.7. However, at these large eccentricities that are typical of horizontal well cementing, the displacement is generally poor and involves a rapid “breakthrough” advance along the wide upper side of the annulus followed only by a much slower removal of the residual fluids. This dynamic renders contact time estimates meaningless. We conclude that some of the simple statements/preferences widely employed in industry do not necessarily apply for all design scenarios. Instead, a detailed study of the fluids involved and the specification of the operational constraints is needed to yield improved displacement quality.

Scaling Formulae for the Wellbore Hydraulics Similitude with Drill Pipe Rotation and Eccentricity

2021 ◽  
Author(s):  
Thad Nosar ◽  
Pooya Khodaparast ◽  
Wei Zhang ◽  
Amin Mehrabian
Keyword(s):  
Power Law ◽  
Flow Rate ◽  
Annular Flow ◽  
Rotation Speed ◽  
Drilling Fluid ◽  
Drill Pipe ◽  
Flow Loop ◽  
Annular Flows ◽  
Fluid Rheology ◽  
Pipe Rotation

Abstract Equivalent circulation density of the fluid circulation system in drilling rigs is determined by the frictional pressure losses in the wellbore annulus. Flow loop experiments are commonly used to simulate the annular wellbore hydraulics in the laboratory. However, proper scaling of the experiment design parameters including the drill pipe rotation and eccentricity has been a weak link in the literature. Our study uses the similarity laws and dimensional analysis to obtain a complete set of scaling formulae that would relate the pressure loss gradients of annular flows at the laboratory and wellbore scales while considering the effects of inner pipe rotation and eccentricity. Dimensional analysis is conducted for commonly encountered types of drilling fluid rheology, namely, Newtonian, power-law, and yield power-law. Appropriate dimensionless groups of the involved variables are developed to characterize fluid flow in an eccentric annulus with a rotating inner pipe. Characteristic shear strain rate at the pipe walls is obtained from the characteristic velocity and length scale of the considered annular flow. The relation between lab-scale and wellbore scale variables are obtained by imposing the geometric, kinematic, and dynamic similarities between the laboratory flow loop and wellbore annular flows. The outcomes of the considered scaling scheme is expressed in terms of closed-form formulae that would determine the flow rate and inner pipe rotation speed of the laboratory experiments in terms of the wellbore flow rate and drill pipe rotation speed, as well as other parameters of the problem, in such a way that the resulting Fanning friction factors of the laboratory and wellbore-scale annular flows become identical. Findings suggest that the appropriate value for lab flow rate and pipe rotation speed are linearly related to those of the field condition for all fluid types. The length ratio, density ratio, consistency index ratio, and power index determine the proportionality constant. Attaining complete similarity between the similitude and wellbore-scale annular flow may require the fluid rheology of the lab experiments to be different from the drilling fluid. The expressions of lab flow rate and rotational speed for the yield power-law fluid are identical to those of the power-law fluid case, provided that the yield stress of the lab fluid is constrained to a proper value.

Comparison of Steady and Unsteady Secondary Flows in a Turbine Stator Cascade

1989 ◽  
Author(s):  
Gregory J. Hebert ◽  
William G. Tiederman
Keyword(s):  
Secondary Flows ◽  
Rotor Blades ◽  
Velocity Measurements ◽  
Flow Loop ◽  
Suction Surface ◽  
Linear Cascade ◽  
Turbine Stator ◽  
Passage Vortex ◽  
Blade Row ◽  
Secondary Flow Structure

The effect of periodic rotor wakes on the secondary flow structure in a turbine stator cascade was investigated. A mechanism simulated the wakes shed from rotor blades bypassing cylindrical rods across the inlet to a linear cascade installed in a recirculating water flow loop. Velocity measurements showed a passage vortex, similar to that seen in steady flow, during the time associated with undisturbed fluid. However, as the rotor wake passed through the blade row, a large crossflow toward the suction surface was observed in the midspan region. This caused the development of two large areas of circulation between the midspan and endwall regions, significantly distorting and weakening the passage vortices.

Use of Tracer Particles for Tracking Fluid Interfaces in Primary Cementing

2019 ◽  
Author(s):  
Amir Taheri ◽  
Jan David Ytrehus ◽  
Ali Taghipour ◽  
Bjørnar Lund ◽  
Alexandre Lavrov ◽  
...  
Keyword(s):  
Numerical Models ◽  
Secondary Flows ◽  
Equivalent Model ◽  
Fluid Interfaces ◽  
Element Analysis ◽  
Two Fluids ◽  
Tracer Particles ◽  
Narrow Side ◽  
Primary Cementing ◽  
Set Up

Abstract In this study, a new approach for detailed tracking of the interface between well fluid and cement by using particles is investigated. This can improve the quality of annular cementing of CO2 wells and thus the storage safety. For this purpose, the displacement mechanisms of Newtonian and non-Newtonian fluids in the annulus of vertical and inclined wells is investigated by using an experimental set-up with an eccentric annular geometry and by finite element analysis of an equivalent model with COMSOL Multiphysics solver. For more efficient displacement, the displacing fluid has a higher density than the displaced fluid, and the intermediate-buoyancy particles that reside at the interface between successive fluids are introduced into the models. Such particles must overcome strong secondary flows in order to travel with the interface. Particle motions are investigated in different experimental and numerical models, and their effectiveness is investigated. The experimental results confirm that while the particles with a size of 425–500 um are unable to overcome the secondary flows in eccentric vertical models and track the interface, they can be useful for tracking the interface between two fluids in an eccentric model with a small inclination to the narrow side. CFD analysis investigates this behavior with more details and shows the effects of some parameters on the particle motions.

How Does a Stationary Sand Bed Affect the Flow Dynamics in an Eccentric Annulus?

2019 ◽  
Author(s):  
Majid Bizhani ◽  
Ergun Kuru
Keyword(s):  
Shear Stress ◽  
Velocity Field ◽  
Turbulent Flow ◽  
Flow Rate ◽  
The Other ◽  
Flow Loop ◽  
Hole Cleaning ◽  
Eccentric Annulus ◽  
Bed Height ◽  
Bed Erosion

Abstract In the drilling operations, it is common to have a stationary bed of the drilled cuttings in the high angle sections of the wellbore. The bed must be removed in the later stages before running the casing, or when it starts to cause high torque and drag on the drill string. The mere act of circulating drilling fluid, however, may not clean the well (i.e., critical flow rate and shear stress for bed erosion must be reached). In an effort to better understand the underlying mechanisms of bed removal process during hole cleaning, in this paper, we look at how the presence of a stationary sand bed affects the flow field in an eccentric annulus. Experiments simulating turbulent flow of water in an eccentric annulus with/without the presence of stationary sand bed have been conducted by using a 9m long horizontal flow loop (with an annular configuration of 95 mm ID outer pipe and 38 mm OD inner pipe). The flow loop was equipped with particle image velocimetry (PIV) system, which was used to collect velocity field data. The PIV data were then used to study the characteristics of the turbulent flow of water in the eccentric annulus. The velocity field and Reynolds stress profiles were analyzed in two planes, one perpendicular to the bed interface and off-center of the annulus, and the other along the center-line of the annulus. Experiments were carried out with the presence of two different height stationary sand beds and also without a sand bed as the control case. The extent to which the presence of the sand bed affects the flow appears to be a strong function of the bed height in the annulus. For a small bed height, deviation of the velocity field from the no bed case was slight. In this case, Reynolds normal and shear stress values were lower near the bed interface comparing to the annulus centerline. On the other hand, for a flow over a thicker bed, this behavior changed, and the flow became more uniform in the annulus (in terms of turbulence and mean flow properties). The results help in understanding the mechanism of bed erosion under constant pump flow rate. From the practical point of view, data presented here suggest that hole cleaning in an eccentric annulus progressively becomes more difficult as the bed becomes smaller. The results also explain why in long horizontal and extended reach wells often wiper trips are required for proper cleaning of the hole.

Test Results and Analytical Predictions for Rotor Drop Testing of an AMB Expander/Generator

2006 ◽  
Author(s):  
Lawrence Hawkins ◽  
Alexei Filatov ◽  
Shamim Imani ◽  
Darren Prosser
Keyword(s):  
High Speed ◽  
High Performance ◽  
Time History ◽  
Test Results ◽  
Direct Drive ◽  
Flow Loop ◽  
Low Loss ◽  
Model Predictions ◽  
Full Speed ◽  
Insight Into

A cryogenic gas expander system that incorporates a high performance, high-speed permanent magnet, direct-drive generator and low loss magnetic bearings is described. Flow loop testing to 30,000 rpm was completed at the system manufacturer’s facility in January 2005, and field installation is scheduled for October 2005. As part of the system testing, the rotor was dropped onto the backup bearings multiple times at an intermediate speed and at 30,000 rpm. Orbit and time-history data from a full speed drop and spin down are presented and discussed in detail. A transient, nonlinear rotordynamic analysis simulation model was developed for the machine to provide insight into the dynamic behavior. The model includes the dead band clearance, the flexible backup bearing support and hard stop. Model predictions are discussed relative to the test data.

Modeling of Newtonian Fluids in Annular Geometries With Inner Pipe Rotation

2010 ◽  
Author(s):  
Mehmet Sorgun ◽  
Jerome J. Schubert ◽  
Ismail Aydin ◽  
M. Evren Ozbayoglu
Keyword(s):  
Axial Velocity ◽  
Pressure Loss ◽  
Tangential Velocity ◽  
Flow Characteristics ◽  
Newtonian Fluids ◽  
Flow Loop ◽  
Eccentric Annulus ◽  
Pressure Losses ◽  
Proposed Model ◽  
Pipe Rotation

Flow in annular geometries, i.e., flow through the gap between two cylindrical pipes, occurs in many different engineering professions, such as petroleum engineering, chemical engineering, mechanical engineering, food engineering, etc. Analysis of the flow characteristics through annular geometries is more challenging when compared with circular pipes, not only due to the uneven stress distribution on the walls but also due to secondary flows and tangential velocity components, especially when the inner pipe is rotated. In this paper, a mathematical model for predicting flow characteristics of Newtonian fluids in concentric horizontal annulus with drill pipe rotation is proposed. A numerical solution including pipe rotation is developed for calculating frictional pressure loss in concentric annuli for laminar and turbulent regimes. Navier-Stokes equations for turbulent conditions are numerically solved using the finite differences technique to obtain velocity profiles and frictional pressure losses. To verify the proposed model, estimated frictional pressure losses are compared with experimental data which were available in the literature and gathered at Middle East Technical University, Petroleum & Natural Gas Engineering Flow Loop (METU-PETE Flow Loop) as well as Computational Fluid Dynamics (CFD) software. The proposed model predicts frictional pressure losses with an error less than ± 10% in most cases, more accurately than the CFD software models depending on the flow conditions. Also, pipe rotation effects on frictional pressure loss and tangential velocity is investigated using CFD simulations for concentric and fully eccentric annulus. It has been observed that pipe rotation has no noticeable effects on frictional pressure loss for concentric annuli, but it significantly increases frictional pressure losses in an eccentric annulus, especially at low flow rates. For concentric annulus, pipe rotation improves the tangential velocity component, which does not depend on axial velocity. It is also noticed that, as the pipe rotation and axial velocity are increased, tangential velocity drastically increases for an eccentric annulus. The proposed model and the critical analysis conducted on velocity components and stress distributions make it possible to understand the concept of hydro transport and hole cleaning in field applications.

scholarly journals An analysis of fast photochemistry over high northern latitudes during spring and summer using in-situ observations from ARCTAS and TOPSE

2012 ◽  
Vol 12 (15) ◽  
pp. 6799-6825 ◽  
Author(s):  
J. R. Olson ◽  
J. H. Crawford ◽  
W. Brune ◽  
J. Mao ◽  
X. Ren ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Limit Of Detection ◽  
Chemical Constituents ◽  
High Sensitivity ◽  
Box Model ◽  
Ozone Production ◽  
The Arctic ◽  
Unconstrained Model ◽  
Model Predictions ◽  
Penn State

Abstract. Observations of chemical constituents and meteorological quantities obtained during the two Arctic phases of the airborne campaign ARCTAS (Arctic Research of the Composition of the Troposphere from Aircraft and Satellites) are analyzed using an observationally constrained steady state box model. Measurements of OH and HO2 from the Penn State ATHOS instrument are compared to model predictions. Forty percent of OH measurements below 2 km are at the limit of detection during the spring phase (ARCTAS-A). While the median observed-to-calculated ratio is near one, both the scatter of observations and the model uncertainty for OH are at the magnitude of ambient values. During the summer phase (ARCTAS-B), model predictions of OH are biased low relative to observations and demonstrate a high sensitivity to the level of uncertainty in NO observations. Predictions of HO2 using observed CH2O and H2O2 as model constraints are up to a factor of two larger than observed. A temperature-dependent terminal loss rate of HO2 to aerosol recently proposed in the literature is shown to be insufficient to reconcile these differences. A comparison of ARCTAS-A to the high latitude springtime portion of the 2000 TOPSE campaign (Tropospheric Ozone Production about the Spring Equinox) shows similar meteorological and chemical environments with the exception of peroxides; observations of H2O2 during ARCTAS-A were 2.5 to 3 times larger than those during TOPSE. The cause of this difference in peroxides remains unresolved and has important implications for the Arctic HOx budget. Unconstrained model predictions for both phases indicate photochemistry alone is unable to simultaneously sustain observed levels of CH2O and H2O2; however when the model is constrained with observed CH2O, H2O2 predictions from a range of rainout parameterizations bracket its observations. A mechanism suitable to explain observed concentrations of CH2O is uncertain. Free tropospheric observations of acetaldehyde (CH3CHO) are 2–3 times larger than its predictions, though constraint of the model to those observations is sufficient to account for less than half of the deficit in predicted CH2O. The box model calculates gross O3 formation during spring to maximize from 1–4 km at 0.8 ppbv d−1, in agreement with estimates from TOPSE, and a gross production of 2–4 ppbv d−1 in the boundary layer and upper troposphere during summer. Use of the lower observed levels of HO2 in place of model predictions decreases the gross production by 25–50%. Net O3 production is near zero throughout the ARCTAS-A troposphere, and is 1–2 ppbv in the boundary layer and upper altitudes during ARCTAS-B.

Displacement Efficiency in Eccentric Annuli

2020 ◽  
Author(s):  
Bjørnar Lund ◽  
Jan David Ytrehus ◽  
Ali Taghipour ◽  
Arild Saasen
Keyword(s):  
Large Diameter ◽  
Scale Up ◽  
Drill String ◽  
Simulation Software ◽  
Systematic Change ◽  
Displacement Efficiency ◽  
Flow Loop ◽  
Laboratory Equipment ◽  
Fluid Displacement ◽  
Displacement Experiments

Abstract A successful primary cementing job requires an efficient fluid displacement process in order to place cement in the annulus between a casing or liner and the formation around the wellbore. This operation is a critical part of the well construction and due to the hardening properties of cement there will be no second chance with this operation. Once hardened, the cement should provide zonal isolation and pressure containment and should do so through the lifetime of the well. Furthermore, the cement shall anchor and support the casing string and protect it against corrosion due to formation fluids. A good quality cement job is important both from an environmental and from an economical perspective. In order to improve recommended cementing practices, and thus also the quality of cementing process, it is necessary to develop cementing simulation software for proper engineering. Detailed data on the displacement efficiency from practical operations are difficult or impossible to obtain. Furthermore, field operations do not allow for a systematic change in fluid properties. To be able to validate the engineering tools it is therefore necessary to perform laboratory measurements with fluids with relevant properties. It is also important to perform these experiments in laboratory equipment of sufficient diameter dimensions to facilitate scale up of the results. The purpose of the present article is to give an overview of cement displacement experiments which were conducted using a large diameter annular flow loop using model fluids with relevant rheological properties. While some results from these experiments have been presented in previous articles, this article is intended to give an overview of all the experiments, including the setup and experimental approach, and provides in more detail results not presented previously. In particular we show results from video recordings which confirm previous conclusions based on conductivity measurements. It is found that eccentricity affects the displacement physics significantly. In washout sections the effects of eccentricity are different and generally smaller since the eccentricity is also reduced. Drill string rotation improves displacement efficiency in all tested cases both within and outside the washout cavity. Since the amount of publicly available experimental data of this type is very limited, the detailed information presented here should be of great interest and relevance for the development and validation of industrial cementing simulation software.

Cementing Irregular Horizontal Wellbores

2021 ◽  
Author(s):  
Alondra Renteria ◽  
Parisa Sarmadi ◽  
Ian Frigaard
Keyword(s):  
3D Model ◽  
Secondary Flows ◽  
Positive Density ◽  
Drilling Mud ◽  
Horizontal Section ◽  
Two Fluids ◽  
Circular Annulus ◽  
Primary Cementing ◽  
Horizontal Wellbores ◽  
Averaged Model

Abstract In this work, we study the effect of borehole irregularities during primary cementing of a horizontal section of well. We use a simplified 2D gap-averaged model to compute the displacement of a drilling mud by a spacer within an elliptical annulus that represents an oval irregularity. We also present a series of 3D numerical simulations using a Volume of Fluid method to capture the interface between the fluids. The 3D model allows us to study the effects of more local irregularities such as wall roughness that can be imported from a caliper log. The dynamics of the displacement of two fluids in a horizontal uniform circular annulus is governed by buoyancy, eccentricity and the rheology of the fluids. A positive density difference combined with a slow mean pumping speed promotes slumping of the second fluid towards the bottom of the annulus. Nevertheless, high eccentricity values (e = 1-standoff) are common due to the weight of the casing pulling downwards, opposing the buoyancy force. Finally, the rheology of the fluids is relevant to determine the presence of un-displaced layers of mud, e.g. at the walls. The same competition described above holds true in the elliptical annulus. Results from the 2D gap-averaged model suggest that the elliptical shape incorporates an additional way of altering the velocity field around it. The effect is more evident when orienting the largest radius of the elliptical annulus at different angles. Results from 3D simulations show that the interface follows irregularities and the local roughness can improve the displacement by inducing secondary flows. However, enlargements result in poor displacement.

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