Multiphase Hydrate Induction Experiment in a Subsea Pipeline

2015 ◽  
Author(s):  
Dinesh Herath ◽  
Samith Rathnayaka ◽  
M. A. Rahman ◽  
Faisal Khan
Keyword(s):  
Oil And Gas ◽  
Flow Line ◽  
Flow Behavior ◽  
Oil And Gas Industry ◽  
Solid Particles ◽  
Development Length ◽  
Flow Loop ◽  
Induction Experiment ◽  
Formation Of Hydrates ◽  
Subsea Pipelines

Formation of hydrates is one of the many challenges faced in the offshore oil and gas industry. It may result in blockage of subsea pipelines and equipment, which may result in flow line rupture and process accident. Although extensive experiment study is conducted to better understand the nucleation of hydrates and their slug flow behavior in gas-water/oil systems. However, there is limited understanding regarding the effects of multiphase fluid dynamics and geometric scales on the formation/growth of hydrates in subsea pipelines. In this paper a multiphase lab scale flow loop set-up is proposed to study the effects of pipe diameter, wall roughness, solid particles and hydrodynamic properties. The multiphase development length of a pipe for varying geometric and flow parameters is also analyzed considering three phase mixture properties. This study will help in identifying the accurate development length for gas/liquid/solid multiphase flow.

Challenges in Hydrate Plug Prevention in Pipelines Seen Over the Lifetime of a Field

2009 ◽  
Author(s):  
Casper Hadsbjerg ◽  
Kristian Krejbjerg
Keyword(s):  
Oil And Gas ◽  
Formation Rate ◽  
Hydrate Formation ◽  
Extended Period ◽  
Oil And Gas Industry ◽  
High Water ◽  
Point Of View ◽  
Field Development ◽  
Hydrate Plug ◽  
Subsea Pipelines

When the oil and gas industry explores subsea resources in remote areas and at high water depths, it is important to have advanced simulation tools available in order to assess the risks associated with these expensive projects. A major issue is whether hydrates will form when the hydrocarbons are transported to shore in subsea pipelines, since the formation of a hydrate plug might shut down a pipeline for an extended period of time, leading to severe losses. The industry practices a conservative approach to hydrate plug prevention, which is the addition of inhibitors to ensure that hydrates cannot form under pipeline pressure and temperature conditions. The addition of inhibitors to subsea pipelines is environmentally unfriendly and also a very costly procedure. Recent efforts has therefore focused on developing models for the hydrate formation rate (hydrate kinetics models), which can help determine how fast hydrates might form a plug in a pipeline, and whether the amount of inhibitor can be reduced without increasing the risk of hydrate plug formation. The main variables determining whether hydrate plugs form in a pipeline are: 1) the ratio of hydrocarbons to water, 2) the composition of the hydrocarbons, 3) the flowrates/flow regimes in the pipeline, 4) the amount of inhibitor in the system. Over the lifetime of a field, all 4 variables will change, and so will the challenge of hydrate plug prevention. This paper will examine the prevention of hydrate plugs in a pipeline, seen from a hydrate kinetics point of view. Different scenarios that can occur over the lifetime of a field will be investigated. Exemplified through a subsea field development, a pipeline simulator that considers hydrate formation in a pipeline is used to carry out a study to shed light on the most important issues to consider as conditions change. The information gained from this study can be used to cut down on inhibitor dosage, or possibly completely remove the need for inhibitor.

Maximum Drag Reduction Asymptote of Polymeric Fluid Flow in Coiled Tubing

2008 ◽  
Vol 131 (1) ◽  
Author(s):  
Subhash N. Shah ◽  
Yunxu Zhou
Keyword(s):  
Drag Reduction ◽  
Oil And Gas ◽  
Guar Gum ◽  
Oil And Gas Industry ◽  
Flow Loop ◽  
Polymeric Fluids ◽  
Curvature Ratio ◽  
Coiled Tubing ◽  
Industry Applications ◽  
Maximum Drag Reduction

This study experimentally investigates the drag reduction characteristics of the most commonly used polymer fluids in coiled tubing applications. The flow loop employed consists of 12.7mm straight and coiled tubing sections. The curvature ratio (a∕R, where a and R are the radii of the tubing and the reel drum, respectively) investigated is from 0.01 to 0.076, which covers the typical curvature ratio range encountered in the oil and gas industry applications. Fluids tested include xanthan gum, guar gum, and hydroxypropyl guar at various polymer concentrations. It is found that the drag reduction in coiled tubing is significantly lower than that in straight tubing, probably due to the effect of secondary flow in curved geometry. The onset of drag reduction is also found to be delayed as the curvature ratio was increased. A correlation for the maximum drag reduction (MDR) asymptote in coiled tubing is developed. When the curvature ratio is set to zero, the new correlation reduces to the well-known Virk’s MDR asymptote for dilute polymer solutions in straight pipes. A new drag reduction envelope is proposed for the analysis of drag reduction behavior of polymeric fluids in coiled tubing. Application of the new drag reduction envelope is also discussed.

scholarly journals Effect of Gain in Soil Friction on the Walking Rate of Subsea Pipelines

2019 ◽  
Vol 7 (11) ◽  
pp. 401 ◽  
Author(s):  
Zhaohui Hong ◽  
Dengfeng Fu ◽  
Wenbin Liu ◽  
Zefeng Zhou ◽  
Yue Yan ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Pipeline System ◽  
Gas Industry ◽  
Steel Catenary Riser ◽  
Wide Range ◽  
Offshore Oil And Gas ◽  
Subsea Pipelines ◽  
Offshore Oil ◽  
Pipeline Design

Subsea pipelines are commonly employed in the offshore oil and gas industry to transport high-pressure and high-temperature (HPHT) hydrocarbons. The phenomenon of pipeline walking is a topic that has drawn a great deal of attention, and is related to the on-bottom stability of the pipeline, such as directional accumulation with respect to axial movement, which can threaten the security of the entire pipeline system. An accurate assessment of pipeline walking is therefore necessary for offshore pipeline design. This paper reports a comprehensive suite of numerical analyses investigating the performance of pipeline walking, with a focus on the effect of increasing axial soil resistance on walking rates. Three walking-driven modes (steel catenary riser (SCR) tension, downslope, and thermal transient) are considered, covering a wide range of influential parameters. The variation in walking rate with respect to the effect of increased soil friction is well reflected in the development of the effective axial force (EAF) profile. A method based on the previous analytical solution is proposed for predicting the accumulated walking rates throughout the entire service life, where the concept of equivalent soil friction is adopted.

Coiled tubing drilling for unconventional reservoirs: the importance of cuttings transport in directional drilling

2014 ◽  
Vol 54 (1) ◽  
pp. 329
Author(s):  
Mohammadreza Kamyab ◽  
Nelson Chin ◽  
Vamegh Rasouli ◽  
Soren Soe ◽  
Swapan Mandal
Keyword(s):  
Rheological Properties ◽  
Oil And Gas ◽  
Fluid Velocity ◽  
Oil And Gas Industry ◽  
Unconventional Reservoirs ◽  
Directional Drilling ◽  
Flow Loop ◽  
Cuttings Transport ◽  
Cleaning Efficiency ◽  
Coiled Tubing

Coiled tubing (CT) technology has long been used in the oil and gas industry for workover and stimulation applications; however, the application of this technology for drilling operations has also been used more recently. Faster tripping, less operational time, continuous and safer operation, and the requirement for fewer crew members are some of the advantages that make CT a good technique for drilling specially deviated wells, in particular, in unconventional reservoirs for the purpose of improved recovery. Cuttings transport in deviated and horizontal wells is one of the challenges in directional drilling as it is influenced by different parameters including fluid velocity, density and rheological properties, as well as hole deviation angle, annulus geometry and particle sizes. To understand the transportation of the cuttings in the annulus space, therefore, it is useful to perform physical simulations. In this study the effect of wellbore angle and fluid rheological properties were investigated physically using a flow loop that has been developed recently for this purpose. The minimum transportation velocity was measured at different angles and an analysis was performed to study the fluid carrying capacity and hole cleaning efficiency. The results indicated how the change in wellbore angle could change the cuttings transport efficiency.

Numerical Investigation of Sand-Screen Performance in the Presence of Adhesive Effects for Enhanced Sand Control

SPE Journal ◽  
2019 ◽  
Vol 24 (05) ◽  
pp. 2195-2208 ◽  
Author(s):  
Siti Nur Shaffee ◽  
Paul F. Luckham ◽  
Omar K. Matar ◽  
Aditya Karnik ◽  
Mohd Shahrul Zamberi
Keyword(s):  
Management Practices ◽  
Oil And Gas ◽  
Voronoi Tessellation ◽  
Oil And Gas Industry ◽  
Solid Particles ◽  
Particle Adhesion ◽  
Sand Production ◽  
Gas Industry ◽  
Particle Filtration ◽  
Sand Control

Summary In many industrial processes, an effective particle–filtration system is essential for removing unwanted solids. The oil and gas industry has explored various technologies to control and manage excessive sand production, such as by installing sand screens or injecting consolidation chemicals in sand–prone wells as part of sand–management practices. However, for an unconsolidated sandstone formation, the selection and design of effective sand control remains a challenge. In recent years, the use of a computational technique known as the discrete–element method (DEM) has been explored to gain insight into the various parameters affecting sand–screen–retention behavior and the optimization of various types of sand screens (Mondal et al. 2011, 2012, 2016; Feng et al. 2012; Wu et al. 2016). In this paper, we investigate the effectiveness of particle filtration using a fully coupled computational–fluid–dynamics (CFD)/DEM approach featuring polydispersed, adhesive solid particles. We found that an increase in particle adhesion reduces the amount of solid in the liquid filtrate that passes through the opening of a wire–wrapped screen, and that a solid pack of particle agglomerates is formed over the screen with time. We also determined that increasing particle adhesion gives rise to a decrease in packing density and a diminished pressure drop across the solid pack covering the screen. This finding is further supported by a Voronoi tessellation analysis, which reveals an increase in porosity of the solid pack with elevated particle adhesion. The results of this study demonstrate that increasing the level of particle agglomeration, such as by using an adhesion–promoting chemical additive, has beneficial effects on particle filtration. An important application of these findings is the design and optimization of sand–control processes for a hydrocarbon well with excessive sand production, which is a major challenge in the oil and gas industry.

scholarly journals CFD STUDY OF SAND EROSION IN PIPELINE USING DIFFERENT PERCENTAGE OF ETHYLENE GLYCOL AND DEIONIZED WATER

2020 ◽  
Vol 9 (12) ◽  
pp. 111-125
Keyword(s):  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Skin Friction Coefficient ◽  
Solid Particles ◽  
Sand Particle ◽  
Pipe Bend ◽  
Gas Industry ◽  
Oil Reserves ◽  
Sand Erosion ◽  
Swirl Velocity

Sand productions are inclusive of various types of major key challenges for gas and oil productions as the sand managements are rapidly growing in becoming significant to manage wells of high rates. Since approximately 70% of gas as well oil reserves around the globe are sand formations Sand production is an unavoidable by-product in oil and gas industry as 70% gas and oil reserves of the world oil are sand formation. Transportation of the particles from the wellbore to the surface will cause the damage to the amenities and tools. Wells producing gas and oils can potentially fail because of the erosion of the major solid particles. It can be illustrated through an example like producing wells having considerable amount of production of sand might affect negatively over the fitting and components of the pipeline, well tubing as well as the equipment used for the production. Thus can cause highly priced potential ecofriendly damages, equipment loss and downtime production. The current study provides outcomes gathered through examining and analyzing various factors for determining the severities and amount of the erosion of sand over the pipe bend. To solve the phenomena of the flow of the fluid, this study has used CFD. To design the pipe’s elbow, CATIA-V5 is brought in use and meshing is done with the help of the ANSYS. Different cases will be studied here by varying the percentage of water and EG with respect to sand particle size 160m and 370m. Erosion rate, Skin friction Coefficient and Swirl velocity are the three major effects which will be studied further. Through the observation of the study, it can be said that material’s character and flow velocity are the predominant factors which might affect the rate of sand erosion within the pipelines. The observation is made over every factor and is also analyzed.

Clustering, Connectivity and Flow in Naturally Fractured Reservoir Analogs

2021 ◽  
Author(s):  
Ajay K. Sahu ◽  
Ankur Roy
Keyword(s):  
Fractal Dimension ◽  
Oil And Gas ◽  
Flow Behavior ◽  
Oil And Gas Industry ◽  
Fracture Network ◽  
Natural Fracture ◽  
Fractured Reservoir ◽  
Fracture Networks ◽  
Gas Industry ◽  
Network Geometry

Abstract A previous study by the authors on synthetic fractal-fracture networks showed that lacunarity, a parameter that quantifies scale-dependent clustering in patterns, can be used as a proxy for connectivity and also, is an indicator of fluid flow in such model networks. In this research, we apply the concepts thus developed to the study of fractured reservoir analogs and seek solutions to more practical problems faced by modelers in the oil and gas industry. A set of seven nested fracture networks from the Devonian Sandstone of Hornelen Basin, Norway that have the same fractal-dimension but are mapped at different scales and resolutions is considered. We compare these seven natural fracture maps in terms of their lacunarity and connectivity values to test whether the former is a reasonable indicator of the latter. Additionally, these maps are also flow simulated by implementing a fracture continuum model and using a streamline simulator, TRACE3D. The values of lacunarity, connectivity and fluid recovery thus obtained are pairwise correlated with one another to look for possible relationships. The results indicate that while fracture maps that have the same fractal dimension show almost similar connectivity values, there exist subtle differences such that both the connectivity and clustering values change systematically with the scale at which the fracture networks are mapped. It is further noted that there appears to be a very good correlation between clustering, connectivity, and fluid recovery values for these fracture networks that belong to the same fractal system. The overall results indicate that while the fractal dimension is an important parameter for characterizing a specific type of fracture network geometry, it is the lacunarity or scale-dependent clustering attribute that controls connectivity in fracture maps and hence the flow properties. This research may prove helpful in quickly evaluating connectivity of fracture networks based on the lacunarity parameter. This parameter can therefore, be used for calibrating Discrete Fracture Network (DFN) models with respect to connectivity of reservoir analogs and can possibly replace the fractal dimension which is more commonly used in software that model DFNs. Additionally, while lacunarity has been mostly used for understanding network geometry in terms of clustering, we, for the first time, show how this may be directly used for understanding the potential flow behavior of fracture networks.

Novel In-Line Inspection Tool for Deposit Characterization in Pipelines

2021 ◽  
Author(s):  
Ossi Lehtikangas ◽  
Arto Voutilainen ◽  
Antti Nissinen ◽  
Pasi Laakkonen ◽  
Sinoj Cyriac ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Test Results ◽  
Flow Loop ◽  
Electrical Tomography ◽  
Gas Industry ◽  
Chemical Inhibitors ◽  
Multi Phase Flow ◽  
Multi Phase ◽  
Production Problems

Abstract Deposition formation inside pipelines is a major and growing problem in the oil and gas industry. The optimal use of prevention and remediation tools such as chemical inhibitors and cleaning processes could lead to major savings due to minimized production problems and optimized pipe cleaning costs. This requires characterization and quantification of the actual deposits inside pipelines and downholes. Recently, a novel deposition inline inspection sensor moving inside the pipeline has been proposed based on "inside-out" electrical tomography. In this sensor, the distribution of electrical properties between the sensor and the pipe wall are estimated based on measurements carried out using electrodes around the sensor. In this study, the next generation sensor moving inside the pipeline is described and a deep neural network based approach to deposit estimation is introduced. Test results from a 70 m long semi-industrial scale flow loop containing paraffin wax and calcium carbonate deposits of different thicknesses are shown. Challenges include the changing position and orientation of the sensor during the low. The results show that the sensor is able to measure both deposit thickness and type with good accuracy which indicates that the sensor is suitable for industrial use. Accurate knowledge about deposits allows future blockage prevention, detecting build-up locations in the early phase, increasing accuracy of multi-phase flow and deposition models, optimization of chemical use and validation of deposit cleaning tools before integrity campaigns leading to overall reduced pipeline operation costs.

Experimental Characterization of Particle-Laden Air Flow in a Horizontal Pipe

2015 ◽  
Author(s):  
Y. Dai ◽  
T. S. Khan ◽  
M. S. Alshehhi ◽  
L. Khezzar
Keyword(s):  
Oil And Gas ◽  
Oil And Gas Industry ◽  
Solid Particles ◽  
Horizontal Pipe ◽  
Gas Industry ◽  
Black Powder ◽  
Powder Samples ◽  
Flow Through

In many engineering applications, movement of micron and submicron size solid particles with compressed air or gas causes major engineering problems as in the case of black powder in oil and gas industry. Therefore, understanding its physical and flow dynamics characteristics inside a pipeline can be very useful to efficiently manage pipelines contamination issues. This paper presents an experimental study carried out to simulate characteristics of air-sand particles flow through a transparent horizontal pipe with various flow conditions. Experimental analysis focuses on determination of critical pickup velocity of the solid particles and measurement of pressure drop across the sand bed of various blockage ratios. Results have been compared with previous studies in literature. Limited experiments are conducted using black powder samples as well. Comparison of results shows vast deviation between sand and black powder behavior.

CFD Simulation of Multiphase Flow in Concentric Annuli

2018 ◽  
Author(s):  
Amina Shynybayeva ◽  
Luis R. Rojas-Solórzano ◽  
Kristian Sveen
Keyword(s):  
Multiphase Flow ◽  
Oil And Gas ◽  
Cfd Simulation ◽  
Flow Behavior ◽  
Droplet Diameter ◽  
Turbulence Models ◽  
Oil And Gas Industry ◽  
Continuous Phase ◽  
Two Phase ◽  
Well Design

Multiphase flow is commonly found in almost every process related to oil and gas industry. The precise prediction of the flow behavior is essential to provide safe and efficient hydrocarbon recovery. An accurate characterization of multiphase flow plays a major role in well design optimization and development of successful production and transportation facilitiess. Even though the hydrodynamic behavior of multiphase flow in various pipe geometries typically found in the industry has been widely studied, there is still very little known about the flow pattern and hydrodynamic conditions presented in horizontal annular geometry. Current work presents Computational Fluid Dynamics (CFD) simulation of two-phase oil-water flow in horizontal concentric annuli using different turbulence models and Eulerian-Eulerian continuous-disperse interphase drag model. Water was modelled as disperse phase, while oil was considered as continuous phase. Effect of water droplet diameter in the interphase model is extensively discussed in this paper. Results of the simulations are compared to the experimental data for a variety of liquid velocities and water cuts.

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