Effect of Particle Size and Viscosity on Erosion in Annular and Slug Flow

2012 ◽  
Author(s):  
N. R. Kesana ◽  
J. M. Throneberry ◽  
B. S. McLaury ◽  
S. A. Shirazi ◽  
E. F. Rybicki
Keyword(s):  
Multiphase Flow ◽  
Electrical Resistance ◽  
Slug Flow ◽  
Annular Flow ◽  
Oil And Gas ◽  
Flow Regimes ◽  
Operating Conditions ◽  
Solid Particles ◽  
Metal Loss ◽  
Head Probe

Solid particle erosion is a mechanical process in which material is removed from a surface due to impacts of solid particles transported within a fluid. It is a common problem faced by the petroleum industry, as solid particles are also produced along with oil and gas. The erosion not only causes losses resulting from repairs and decreased production but also causes safety and environmental concerns. Therefore, the metal losses occurring in different multiphase flow patterns need to be studied and understood in order to develop protective guidelines for oil and gas production equipment. A large scale boom loop, which is capable of generating a wide variety of multiphase flow regimes was used for conducting experiments. Specifically, this work examines erosion measurements in multiphase slug and annular flow regimes. These flow regimes are selected since they produce higher metal losses than other flow regimes, and they also occur for a wide variety of operating conditions. Experiments are performed on a horizontal 0.0762 m (3-inch) diameter pipe, with superficial gas velocities ranging from 15.2 m/s (50 ft/s) to 45.7 m/s (150 ft/s) and superficial liquid velocities ranging from 0.46 m/s (1.5 ft/s) to 0.76 m/s (2.5 ft/s), for liquid viscosities of 1 cP and 10 cP. Carboxymethyl Cellulose (CMC) was used to increase the viscosity of the liquid without significantly altering the density of the liquid. Three different sand sizes (20, 150 and 300 micron sand) were used for performing tests. The shapes of the sand are also different with the 20 and 300 micron sand being sharper than the 150 micron sand. Erosion measurements are taken using Electrical Resistance (ER) probes which relate the change in electrical resistance to the change in the thickness of an exposed element resulting from erosion. Two probes are placed in a bend and another probe is placed in a straight section of pipe. The probes in the bend are flat-head probes, and they are placed flush with the outer wall in the 45 and 90 degree positions. The probe in the straight pipe is an angle-head probe which protrudes into the flow with the face placed in the center of the pipe. Under the flow conditions investigated, the angle-head probe measures the maximum erosion due to its placement. Results demonstrate a significant increase in the metal loss occurs when increasing the superficial gas velocity and decreasing the superficial liquid velocity. The effect of changing the viscosity of the liquid is not as clear. Results suggest a slight increase in metal loss by increasing the viscosity from 1cP to 10 cP in slug flow. However, for annular flow, higher erosion occurs for the lower liquid viscosity considered.

Ultrasonic Measurement of Multiphase Flow Erosion Patterns in a Standard Elbow

2012 ◽  
Author(s):  
N. R. Kesana ◽  
S. A. Grubb ◽  
B. S. McLaury ◽  
S. A. Shirazi
Keyword(s):  
Multiphase Flow ◽  
Oil And Gas ◽  
Particle Diameter ◽  
Gas Production ◽  
Solid Particles ◽  
Economic Losses ◽  
Metal Loss ◽  
Straight Pipe ◽  
Non Invasive ◽  
Good Agreement

Solid particle erosion is a mechanical process in which material is removed from a surface due to impacts of solid particles transported within a fluid. It is a common problem faced by the petroleum industry, as solid particles are also produced along with oil and gas. The erosion not only causes economic losses resulting from repairs and decreased production but also causes safety and environmental concerns. Therefore, the metal losses occurring in different multiphase flow regimes need to be studied and understood in order to develop protective guidelines for oil and gas production equipment. In the current study, a novel non-invasive ultrasonic (UT) device has been developed and implemented to measure the metal loss at 16 different locations inside an elbow. Initially, experiments were performed with a single-phase carrier fluid (gas-sand) moving in the pipeline, and the erosion magnitudes are compared with Computational Fluid Dynamics (CFD) results and found to be in good agreement. Next, experiments were extended to the multiphase slug flow regime. Influence of particle diameter and liquid viscosity were also studied. Two different particle sizes (150 and 300 micron sand) were used for performing tests. The shapes of the sand are also different with the 300 micron sand being sharper than the 150 micron sand. Three different liquid viscosities were used for the present study (1 cP, 10 cP and 40 cP). Carboxymethyl Cellulose (CMC) was used to increase the viscosity of the liquid without significantly altering the density of the liquid. While performing the UT experiments, simultaneous metal loss measurements were also made using an intrusive Electrical Resistance (ER) probe in a section of straight pipe. The probe in the straight pipe is an angle-head probe which protrudes into the flow with the face placed in the center of the pipe. The UT erosion measurements in a bend are also compared with experimental data obtained placing an intrusive flat head ER probe flush in a bend, and the results were found to be in good agreement. Finally, the non-invasive NanoUT permanent placement temperature compensated ultrasonic wall thickness device developed for this work has the capability of measuring metal loss at many locations and also identifying the maximum erosive location on the pipe bend.

Effect of Drag-Reducing Agents in Multiphase Flow Pipelines

1998 ◽  
Vol 120 (1) ◽  
pp. 15-19 ◽  
Author(s):  
C. Kang ◽  
R. M. Vancko ◽  
A. S. Green ◽  
H. Kerr ◽  
W. P. Jepson
Keyword(s):  
Multiphase Flow ◽  
Pressure Gradient ◽  
Slug Flow ◽  
Annular Flow ◽  
Flow Regimes ◽  
Reducing Agents ◽  
Pressure Gradients ◽  
Horizontal Pipes ◽  
Flow Pressure ◽  
Inclined Pipes

The effect of drag-reducing agents (DRA) on pressure gradient and flow regime has been studied in horizontal and 2-deg upward inclined pipes. Experiments were conducted for different flow regimes in a 10-cm i.d., 18-m long plexiglass system. The effectiveness of DRA was examined for concentrations ranging from 0 to 75 ppm. Studies were done for superficial liquid velocities between 0.03 and 1.5 m/s and superficial gas velocities between 1 and 14 m/s. The results indicate that DRA was effective in reducing the pressure gradients in single and multiphase flow. The DRA was more effective for lower superficial liquid and gas velocities for both single and multiphase flow. Pressure gradient reductions of up to 42 percent for full pipe flow, 81 percent for stratified flow, and 35 percent for annular flow were achieved in horizontal pipes. In 2 deg upward inclination, the pressure gradient reduction for slug flow, with a concentration of 50 ppm DRA, was found to be 28 and 38 percent at superficial gas velocities of 2 and 6 m/s, respectively. Flow regimes maps with DRA were constructed in horizontal pipes. Transition to slug flow with addition of DRA was observed to occur at higher superficial liquid velocities.

Effect of Particle Size and Liquid Viscosity on Erosion in Annular and Slug Flow

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
N. R. Kesana ◽  
J. M. Throneberry ◽  
B. S. McLaury ◽  
S. A. Shirazi ◽  
E. F. Rybicki
Keyword(s):  
Electrical Resistance ◽  
Flow Regimes ◽  
Outer Wall ◽  
Operating Conditions ◽  
Sand Erosion ◽  
Diameter Pipe ◽  
The Face ◽  
Effect Of Particle Size ◽  
Head Probe ◽  
Made In

Erosion measurements in multiphase slug and annular flow regimes have been made in a horizontal 76.2 mm (3-in.) diameter pipe. These flow regimes are selected since they produce higher metal losses than other flow regimes, and they also occur for a wide variety of operating conditions. Experiments are performed with superficial gas velocities ranging from 15.2 m/s (50 ft/s) to 45.7 m/s (150 ft/s) and superficial liquid velocities ranging from 0.46 m/s (1.5 ft/s) to 0.76 m/s (2.5 ft/s), for liquid viscosities of 1 cP and 10 cP. Three different sand sizes (20, 150, and 300 μm sand) were used for performing tests. The shapes of the sand are also different with the 20 and 300 μm sand being sharper than the 150 μm sand. Erosion measurements are obtained using electrical resistance (ER) probes which relate the change in electrical resistance to the change in the thickness of an exposed element resulting from erosion. Two probes are placed in a bend and another probe is placed in a straight section of pipe. The probes in the bend are flat-head probes, and they are placed flush with the outer wall in the 45 deg and 90 deg positions. The probe in the straight pipe is an angle-head probe which protrudes into the flow with the face placed in the center of the pipe.

Forces on Bends and T-Joints due to Multiphase Flow

2010 ◽  
Author(s):  
S. P. C. Belfroid ◽  
M. F. Cargnelutti ◽  
W. Schiferli ◽  
Marlies van Osch
Keyword(s):  
Multiphase Flow ◽  
Flow Regime ◽  
Slug Flow ◽  
Annular Flow ◽  
Gas Flow ◽  
Stratified Flow ◽  
Operating Conditions ◽  
Large Radius ◽  
Flow Conditions ◽  
Wide Range

To be able to assess the mechanical integrity of piping structures for loading to multiphase flow conditions, air-water experiments were carried out in a horizontal 1″ pipe system. Forces and accelerations were measured on a number of bends and T-joint configurations for a wide range of operating conditions. Five different configurations were measured: a baseline case consisting of a straight pipe only, a sharp edged bend, a large radius bend, a symmetric T-joint and a T-joint with one of the arms closed off. The gas flow was varied from a superficial velocity of 0.1 to 30 m/s and the liquid flow was varied from 0.05 to 2 m/s. This operating range ensures that the experiment encompasses all possible flow regimes. The magnitude of the measured forces was found to vary over a wide range depending on the flow regime. For slug flow conditions very high force levels were measured, up to 4 orders of magnitude higher than in single phase flow for comparable velocities. The annular flow regime resulted in the (relative) lowest forces, although the absolute amplitude is of the same order as in the case of slug flow. In case of slug flow, the measured results can be described assuming a simple slug unit model. For both the frequency and amplitude the available models can be used in assessments. In annular and stratified flow a different model is required, since no slug unit is present. Instead, the amplitude of the excitation force can be estimated using mixture properties. To predict the main frequency for the annular flow and stratified flow additional experiments are required.

Ultrasonic Measurement of Multiphase Flow Erosion Patterns in a Standard Elbow

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
N. R. Kesana ◽  
S. A. Grubb ◽  
B. S. McLaury ◽  
S. A. Shirazi
Keyword(s):  
Multiphase Flow ◽  
Oil And Gas ◽  
Particle Diameter ◽  
Gas Production ◽  
Solid Particles ◽  
Economic Losses ◽  
Metal Loss ◽  
Straight Pipe ◽  
Carrier Fluid ◽  
Good Agreement

Solid particle erosion is a mechanical process in which material is removed from a surface due to impacts of solid particles transported within a fluid. It is a common problem faced by the petroleum industry, as solid particles are also produced along with oil and gas. The erosion not only causes economic losses resulting from repairs and decreased production but also causes safety and environmental concerns. Therefore, the metal losses occurring in different multiphase flow regimes need to be studied and understood in order to develop protective guidelines for oil and gas production equipment. In the current study, a novel noninvasive ultrasonic (UT) device has been developed and implemented to measure the metal loss at 16 different locations inside an elbow. Initially, experiments were performed with a single-phase carrier fluid (gas-sand) moving in the pipeline, and the erosion magnitudes are compared with computational fluid dynamics (CFD) results and found to be in good agreement. Next, experiments were extended to the multiphase slug flow regime. Influence of particle diameter and liquid viscosity were also studied. Two different particle sizes (150 and 300 μm sand) were used for performing tests. The shapes of the sand are also different with the 300 μm sand being sharper than the 150 μm sand. Three different liquid viscosities were used for the present study (1 cP, 10 cP, and 40 cP). While performing the UT experiments, simultaneous metal loss measurements were also made using an intrusive electrical resistance (ER) probe in a section of straight pipe. The probe in the straight pipe is an angle-head probe which protrudes into the flow with the face placed in the center of the pipe. The UT erosion measurements in a bend are also compared with experimental data obtained placing an intrusive flat head ER probe flush in a bend, and the results were found to be in good agreement. Finally, the noninvasive nano UT permanent placement temperature compensated ultrasonic wall thickness device developed for this work has the capability of measuring metal loss at many locations and also identifying the maximum erosive location on the pipe bend.

A Novel Two-Phase Gas\Liquid Slug Flow Measurement System Using a T-Junction Separator and Ultrasonic Measurements

2008 ◽  
Author(s):  
Khalifa M. Khalifa ◽  
Mike L. Sanderson
Keyword(s):  
Multiphase Flow ◽  
Systems Engineering ◽  
Measurement System ◽  
Slug Flow ◽  
Flow Measurement ◽  
Cross Correlation ◽  
Flow Regimes ◽  
Oil And Gas Industry ◽  
Wide Range ◽  
Ultrasonic Measurements

Over the last decade, the development and deployment of in-line multiphase flow metering systems has been a major focus worldwide. Accurate measurement of multiphase flow in the oil and gas industry is difficult because it occurs in wide range of flow regimes and multiphase meters do not generally perform well under the intermittent slug flow conditions which commonly occur in oil production. A novel ultrasonic multiphase metering concept has been proposed and investigated which measures the flow rates of the liquid and gas phases from ultrasonic measurements made in two different flow regimes – partially separated and homogeneous — in the same measurement system and fuses the data from the different flow regimes to obtain improved overall measurement accuracy. The system employs a partial gas/liquid separation using a T-junction configuration and a combination of Doppler and cross correlation. The partially separated flow regimes uses ultrasonic cross correlation measurement for the liquid flow measurement which has gas entrained within it. The homogeneous regime employs ultrasonic Doppler method. This approach has been tested on water/air flows on a 50mm facility in the Department of Process and Systems Engineering. The liquid and gas flowrate measurements using the proposed techniques were compared with a reference measurement and good agreements between these two measurements were obtained with error ranging from ± 2% and 10%, respectively. Such a performance offers the potential for an in-line multiphase flowmeter with improved performance.

A Combined CFD-Mechanistic Approach for Predicting Solid Particle Erosion in Annular Flow in Pipe Fittings and Elbows

2020 ◽  
Author(s):  
Farzin Darihaki ◽  
Elham Fallah Shojaie ◽  
Jun Zhang ◽  
Siamack A. Shirazi
Keyword(s):  
Multiphase Flow ◽  
Solid Particle ◽  
Annular Flow ◽  
Large Diameter ◽  
Solid Particles ◽  
Wall Material ◽  
Solid Particle Erosion ◽  
Flow Conditions ◽  
Particle Erosion ◽  
Wide Range

Abstract In internal flows, solid particles carried by the fluid could damage pipelines and fittings. Particles that are entrained in the fluid can cross streamlines and transfer a part of their momentum to the internal surface by impacts and cause local wall material degradation. Over the past decades, a wide range of models is introduced to predict particle erosion which includes empirical models, mechanistic models, and CFD which is currently the state-of-art numerical approach to simulate the erosion process. Multiphase flow under annular flow conditions adds to the complexity of the model. Although with the current computational capabilities transient CFD models are effectively applicable, this type of transient multiphase approach is not practical yet for engineering prediction of erosion especially for the large diameter applications with huge computational domains. Therefore, the presented combined approach could be utilized to obtain erosion rates for large diameter cases. Thus, an approach combining CFD and mechanistic multiphase models characterizing annular flow is developed to predict solid particle erosion. Different factors including film thickness in pipes and fittings which are affecting erosion under gas-dominated multiphase flow conditions are investigated. The results from the current approach are compared to experimental data and transient CFD simulations for annular flow in elbows showing a very good agreement with both.

Fatigue Analysis of Subsea Jumpers due to Slug Flow

2014 ◽  
Author(s):  
Bob (H. E. J. ) van der Heijden ◽  
Henk Smienk ◽  
Andrei V. Metrikine
Keyword(s):  
Pressure Drop ◽  
Static Analysis ◽  
Fatigue Damage ◽  
Slug Flow ◽  
Oil And Gas ◽  
Operating Conditions ◽  
Design Phase ◽  
Line System ◽  
Excitation Mechanisms ◽  
The Difference

Rigid steel jumpers are used in a subsea flow line system to connect subsea components. They provide a certain flexibility with respect to installation and operating conditions. This flexibility makes the jumper susceptible to slug flow induced vibrations. Slug flow can be described as an alternating flow of long oil and gas bubbles which flow at the gas velocity. The alternation between oil and gas density causes loads on the jumper which causes the jumper to vibrate. Two excitation mechanisms can be identified; 1) The variation in weight along the straight sections and 2) the difference in impact loads on the bends. Due to the cyclic nature of these loads fatigue can cause the jumper to fail. As a main contractor of SURF-projects (Subsea Umbilicals Risers and Flowlines) Heerema Marine Contractors (HMC) is responsible for the engineering, procurement, construction and installation (EPCI) of the entire project scope, including the design of the subsea jumpers. Hence this paper has been set up by HMC and the Delft University of Technology to study slug flow induced fatigue in subsea jumpers and in order to find new design considerations. In the early design phase of a subsea jumper the offshore industry commonly uses, to authors knowledge, a static analysis to predict the fatigue damage caused by slug flow. Since the vibrations caused by slug flow are not incorporated in a static analysis an accurate tradeoff between flexibility and fatigue lifetime cannot be made during the design phase. As this tradeoff during the design phase is desirable, a new dynamic and more accurate analysis method has been developed which takes these vibrations into account. A comparison between this new methodology and the common industry method is made in order to quantify the difference in analyzed fatigue damage due to slug flow induced vibration. Additionally the effects of a pressure drop over a passing slug is also investigated to determine if a pressure drop should be incorporated as a design factor for slug flow induced fatigue. The new dynamic method will also be used to investigate the relation between jumper configuration and high slug flow velocity. It will show what excitation mechanisms are dominant and how this affects the fatigue behavior. Since is be the first time, to authors knowledge, such an extensive analysis of geometries and velocities is undertaken it will provide new insights into slug flow induced fatigue in subsea jumpers in general. The newly found amplification and attenuation of the vibration by the successive impacts on the bends of a subsea jumper are investigated.

Numerical Analyses of the Effects of Bend Orientation on Sand Erosion in Elbows for Annular Flow

2020 ◽  
Author(s):  
Rong Kang ◽  
Haixiao Liu
Keyword(s):  
Numerical Model ◽  
Flow Field ◽  
Multiphase Flow ◽  
Annular Flow ◽  
Oil And Gas ◽  
Particle Model ◽  
Severe Problem ◽  
Hydrocarbon Reservoir ◽  
Sand Erosion ◽  
Sand Particles

Abstract Sand erosion is a severe problem during the transportation of oil and gas in pipelines. The technology of multiphase transportation is widely applied in production, due to its high efficiency and low cost. Among various multiphase flow patterns, annular flow is a common flow pattern in the transportation process. During the transportation of oil and gas from the hydrocarbon reservoir to the final destination, the flow direction of the mixture in pipelines is mainly changed by the bend orientation. The bend orientation obviously changes the distributions of the liquid film and sand particles in annular flow, and this would further affect the sand erosion in elbows. Computational Fluid Dynamics (CFD) is an efficient tool to investigate the issues of sand erosion in multiphase flow. In the present work, a CFD-based numerical model is adopted to analyze the effects of bend orientation on sand erosion in elbows for annular flow. Volume of Fluid (VOF) method is adopted to simulate the flow field of annular flow, and sand particles in the flow field are tracked by employing Discrete Particle Model (DPM) simultaneously. Then, the particle impingement information is combined with the erosion model to obtain the maximum erosion ratio. The present numerical model is validated by experiments conducted in vertical-horizontal upward elbows. Finally, the effects of various bend orientations on the erosion magnitude are investigated according to the numerical simulations.

Distribution of Sand Particles in Horizontal and Vertical Annular Multiphase Flow in Pipes and the Effects on Sand Erosion

2011 ◽  
Vol 133 (2) ◽  
Author(s):  
Brenton S. McLaury ◽  
Siamack A. Shirazi ◽  
Vinod Viswanathan ◽  
Quamrul H. Mazumder ◽  
Gerardo Santos
Keyword(s):  
Multiphase Flow ◽  
Annular Flow ◽  
Solid Particles ◽  
Experimental Results ◽  
Sand Erosion ◽  
Sand Particles ◽  
The Impact ◽  
Upstream Flow

Predicting erosion resulting from the impact of solid particles such as sand is a difficult task, since it is dependent on so many factors. The difficulty is compounded if the particles are entrained in multiphase flow. Researchers have developed models to predict erosion resulting from solid particles in multiphase flow that account for a variety of factors. However, no model currently accounts for the flow orientation on the severity of erosion. This work provides three sets of experimental results that demonstrate pipe orientation can have a significant impact on the amount of erosion for annular flow. A semimechanistic model to predict erosion in annular flow is also outlined that accounts for the upstream flow orientation.

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