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Murat Tutkun - One of the best experts on this subject based on the ideXlab platform.
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two phase gas liquid flow in concentric and fully Eccentric annuli part i flow patterns holdup slip ratio and pressure gradient
Chemical Engineering Science, 2019Co-Authors: Roberto Ibarra, J Nossen, Murat TutkunAbstract:Abstract Horizontal and upward low-inclination gas-water and gas-oil flows are investigated using an Annulus pipe configuration in a high-pressure system (∼400 kPa). The Annulus test section, or the so-called pipe-in-pipe configuration, consists of an outer pipe of 99 mm inside diameter and an inner pipe of 50 mm outside diameter. Two different vertical positions of the inner pipe with respect to outer pipe have been tested; namely concentric configuration where both pipes have the same centreline and fully Eccentric where the inner pipe is placed at the bottom wall of outer pipe. The flow is studied using high-speed photography, differential pressure transducers, and broad-beam gamma densitometers to characterise the flow as function of the liquid phase properties, Annulus Eccentricity, and pipe inclination. Flow regime maps reveal that slug flow appears to be the most common flow feature across the conditions studied in this paper. Flow in the Eccentric Annulus shows a more consistent behaviour (i.e. well-defined flow structures axially and in time) than that observed in the concentric Annulus. Gas-oil flows show more stable phase fraction behaviour across the cross-section compared to that observed in gas-water flows in which the interface shows significant activity promoting the formation of droplets and ligaments that break from the liquid film. This is especially the case with the concentric Annulus configuration. The oil phase regardless of the geometrical configuration tends to fully wet the pipe (made of PVC) as the gas velocity increases, creating a continuous film along the pipe walls. Conversely, the thin film in gas-water flow is not continuous. Discontinuity in the thin film increases with an increase in effective pipe roughness. Given the same inlet flow conditions, the concentric Annulus configuration causes larger pressure drop along the pipe than that obtained in the Eccentric.
Sorgun Mehmet - One of the best experts on this subject based on the ideXlab platform.
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Yatay Kuyulardaki Sıvı-Katı Çift Fazlı Akışın Modellenmesi
Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2017Co-Authors: Ülker Erman, Sorgun MehmetAbstract:Sıvı- katı (kesinti) sistemleri için basınç farkını belirlemek sondaj anında tijlerin dönmesinden ve kesintilerin kuyu içinde bulunmasından dolayı oldukça karışık bir hal alır ve hesaplanması zor bir hale gelir. Kuyudaki kesinti yatağı yüksekliği arttırkça, basınç farkı da artar. Borunun dönmesi eksantrik bir annülüsteki tek fazlı Newton tipi akışkanın basınç farkını arttırırken, sıvı-kesinti sisteminde yatağın erozyunu yüzünden basınç farkında bir azalma gözlemlenir. Bu çalışmada, hesaplamalı akışkanlar dinamiği (CFD) kullanılarak yatay kuyu içinde akan katı (kırınt)ı-sıvı sistemi modellenmiştir. Kesinti taşınım deneyleri akımın, dönme ve delmenin değişik hızlarında yapılmıştır. Deney kesiti içindeki basınç farkı ve durgun ve/veya hareketli kesinti yatağının kalınlığı kaydedilip, CFD sonuçları deneylerden elde edilen verilerle karşılaştırılmıştır. Sonuçlar ise CFD modelinin sürtünmeden kaynaklanan basınç kayıplarını belirleyebildiğini göstermiştir.It is very complex to identify pressure loss for solid-liquid system because of rotating of drillstring during drilling operation and cuttings are present in a wellbore. While incresing cuttings bed thickness in the wellbore, increasing of pressure loss occurs. When rotation of pipe increase pressure loss of cuttingless Newtonian fluids in an Eccentric Annulus, the reason of bed erosion gives a reduction of pressure loss for two phase solid-liquid flow system. Computational fluid dynamics (CFD) is used for modelling of solid (cuttings) – liquid flow inside horizontal wells in this study. Various flow rates, pipe rotation speed, and rate of penetration are arranged for cuttings transport experiments. In the cross section of test section, pressure loss and moving and/or stationary bed thickness are obtained. Comparison of experimental data from experiments and CFD results are done. It is understood that CFD model is good enough to estimate the frictional pressure loss
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Yatay Kuyulardaki Sıvı-Katı Çift Fazlı Akışın Modellenmesi
Theoretical and Applied Mechanical Turkish National Committee, 2015Co-Authors: Ülker Erman, Sorgun MehmetAbstract:Konferans Bildirisi -- Teorik ve Uygulamalı Mekanik Türk Milli Komitesi, 2015Conference Paper -- Theoretical and Applied Mechanical Turkish National Committee, 2015Sıvı- katı (kesinti) sistemleri için basınç farkını belirlemek sondaj anında tijlerin dönmesinden ve kesintilerin kuyu içinde bulunmasından dolayı oldukça karışık bir hal alır ve hesaplanması zor bir hale gelir. Kuyudaki kesinti yatağı yüksekliği arttırkça, basınç farkı da artar. Borunun dönmesi eksantrik bir annülüsteki tek fazlı Newton tipi akışkanın basınç farkını arttırırken, sıvı-kesinti sisteminde yatağın erozyunu yüzünden basınç farkında bir azalma gözlemlenir. Bu çalışmada, hesaplamalı akışkanlar dinamiği (CFD) kullanılarak yatay kuyu içinde akan katı (kırınt)ı-sıvı sistemi modellenmiştir. Kesinti taşınım deneyleri akımın, dönme ve delmenin değişik hızlarında yapılmıştır. Deney kesiti içindeki basınç farkı ve durgun ve/veya hareketli kesinti yatağının kalınlığı kaydedilip, CFD sonuçları deneylerden elde edilen verilerle karşılaştırılmıştır. Sonuçlar ise CFD modelinin sürtünmeden kaynaklanan basınç kayıplarını belirleyebildiğini göstermiştir.It is very complex to identify pressure loss for solid-liquid system because of rotating of drillstring during drilling operation and cuttings are present in a wellbore. While incresing cuttings bed thickness in the wellbore, increasing of pressure loss occurs. When rotation of pipe increase pressure loss of cuttingless Newtonian fluids in an Eccentric Annulus, the reason of bed erosion gives a reduction of pressure loss for two phase solid-liquid flow system. Computational fluid dynamics (CFD) is used for modelling of solid (cuttings) – liquid flow inside horizontal wells in this study. Various flow rates, pipe rotation speed, and rate of penetration are arranged for cuttings transport experiments. In the cross section of test section, pressure loss and moving and/or stationary bed thickness are obtained. Comparison of experimental data from experiments and CFD results are done. It is understood that CFD model is good enough to estimate the frictional pressure loss
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MODELING OF NEWTONIAN FLUIDS IN ANNULAR GEOMETRIES WITH INNER PIPE ROTATION
2010Co-Authors: Sorgun Mehmet, Schubert, Jerome J., Aydın İsmail, Ozbayoglu M. EvrenAbstract: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
I A Frigaard - One of the best experts on this subject based on the ideXlab platform.
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a comparative study of laminar turbulent displacement in an Eccentric Annulus under imposed flow rate and imposed pressure drop conditions
Energies, 2021Co-Authors: Yasaman Foolad, Majid Bizhani, I A FrigaardAbstract: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.
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buoyancy effects on turbulent displacement of viscoplastic fluids from strongly Eccentric horizontal annuli
Physics of Fluids, 2020Co-Authors: Majid Bizhani, I A FrigaardAbstract:We present an experimental and numerical study of the turbulent displacement of viscoplastic fluids in a horizontal Eccentric Annulus. Several experiments where a weighted Newtonian fluid displaces a yield stress fluid under a turbulent flow condition are presented and discussed. These are also used to validate the turbulent displacement model that we use in this study. The model simulator is used to study the mechanisms by which buoyancy influences turbulent displacement in more detail and outside of the range of our experiments. Extreme cases where the generated wall shear stress of the displacing fluid is smaller than the yield stress of the displaced Carbopol are investigated. The results show that buoyancy is ineffective in countering the tendency of the fluid to disperse along the wide gap of the Annulus. In both model and experiment, the outcome of the displacement appears to be controlled by the yield stress of the in situ fluid and the Eccentricity of the Annulus. For fully turbulent flows, the viscosity of the displaced fluid has a negligible effect, and having also negated buoyancy, there appears to be no mechanism to stabilize the turbulent displacement of a yield stress fluid in a severely Eccentric horizontal Annulus. For the underlying industrial process, this means that extreme caution should be used in designing turbulent flow displacements for horizontal wells. There are two solutions: (i) increase the flow rate to generate sufficient stresses (usually not possible due to pump and formation fracture pressure limits) and (ii) ensure a better centralized Annulus (unpopular because of operational constraints).
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turbulent displacement flow of viscoplastic fluids in Eccentric Annulus experiments
Physics of Fluids, 2020Co-Authors: Majid Bizhani, Yasaman Foolad, I A FrigaardAbstract:We study displacement flows in strongly Eccentric annuli, where the in situ fluid is viscoplastic and the displacing fluid is Newtonian. This mimics the situation found in the cementing of horizontal oil and gas wells. In this configuration, it is common that the yield stress of the displaced fluid prevents displacement from the narrow side of the Annulus, where it remains static. We address the question of whether a turbulent flow of the displacing fluid will be effective in removing the static narrow side channel and by what means. The flows proceed with rapid displacement along the wide side of the Annulus, leaving behind a gelled channel of fluid on the narrow side. The narrow side is displaced either slowly or not at all. This depends on both the yield stress of the displaced fluid and the turbulence characteristics of the displacing fluid. We influence the latter through the use of drag-reducing polymers. We show that secondary flows in the turbulent displacing fluid are essential to the displacement and also the increased pressure drops in the turbulent flow. We hypothesize that the displacement is enhanced by the transmission of normal stresses into the gelled layer.
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mud removal and cement placement during primary cementing of an oil well laminar non newtonian displacements in an Eccentric annular hele shaw cell
Journal of Engineering Mathematics, 2002Co-Authors: S H Bittleston, J Ferguson, I A FrigaardAbstract:A two-dimensional model is derived of the displacement flows that occur during primary cementing of oil and gas wells. The displacement geometry is a long narrow Eccentric Annulus, between the casing and the rock formation. The model consists of a series of first-order convection equations for the fluid concentrations and a quasi-linear Poisson-type equation for the stream function. Coupling is through the velocity field and the concentration-dependent fluid properties.
Hansjosef Allelein - One of the best experts on this subject based on the ideXlab platform.
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numerical investigation of subcooled flow boiling in an Annulus under the influence of Eccentricity
Applied Thermal Engineering, 2018Co-Authors: Harish Pothukuchi, Stephan Kelm, B S V Patnaik, B V S S S Prasad, Hansjosef AlleleinAbstract:Abstract The subcooled flow boiling phenomenon usually occurs in a number of industrial applications, such as Pressurized Heavy Water Reactors (PHWR) and heat exchangers in nuclear power plants. The pressure tube deformation, presence of spacer pads, etc., may result in the Eccentricity (e) of the rod bundle which causes coolant flow maldistribution and hence influence the heat transfer characteristics. In the present study, the entire rod bundle is modeled as a single inner rod and Eulerian Eulerian Multiphase Flow (EEMF) and Wall Heat Flux Partition (WHFP) model framework is used to simulate the effect of Eccentricity (e). This model is validated against the available experimental data in the literature and found to be in reasonably good agreement. This framework is also compared and contrasted against the subchannel analysis predictions to highlight the importance of detailed CFD simulations. Furthermore, in the present study, the thermal hydraulics of narrow and wide gap regions are numerically investigated in an Eccentric Annulus. Due to Eccentricity, early phase change, higher wall temperature and vapour volume fraction were noticed in the narrow gap region, compared to the concentric case ( e = 0.0 ), which is undesirable in the PHWR type reactors.
Roberto Ibarra - One of the best experts on this subject based on the ideXlab platform.
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two phase gas liquid flow in concentric and fully Eccentric annuli part i flow patterns holdup slip ratio and pressure gradient
Chemical Engineering Science, 2019Co-Authors: Roberto Ibarra, J Nossen, Murat TutkunAbstract:Abstract Horizontal and upward low-inclination gas-water and gas-oil flows are investigated using an Annulus pipe configuration in a high-pressure system (∼400 kPa). The Annulus test section, or the so-called pipe-in-pipe configuration, consists of an outer pipe of 99 mm inside diameter and an inner pipe of 50 mm outside diameter. Two different vertical positions of the inner pipe with respect to outer pipe have been tested; namely concentric configuration where both pipes have the same centreline and fully Eccentric where the inner pipe is placed at the bottom wall of outer pipe. The flow is studied using high-speed photography, differential pressure transducers, and broad-beam gamma densitometers to characterise the flow as function of the liquid phase properties, Annulus Eccentricity, and pipe inclination. Flow regime maps reveal that slug flow appears to be the most common flow feature across the conditions studied in this paper. Flow in the Eccentric Annulus shows a more consistent behaviour (i.e. well-defined flow structures axially and in time) than that observed in the concentric Annulus. Gas-oil flows show more stable phase fraction behaviour across the cross-section compared to that observed in gas-water flows in which the interface shows significant activity promoting the formation of droplets and ligaments that break from the liquid film. This is especially the case with the concentric Annulus configuration. The oil phase regardless of the geometrical configuration tends to fully wet the pipe (made of PVC) as the gas velocity increases, creating a continuous film along the pipe walls. Conversely, the thin film in gas-water flow is not continuous. Discontinuity in the thin film increases with an increase in effective pipe roughness. Given the same inlet flow conditions, the concentric Annulus configuration causes larger pressure drop along the pipe than that obtained in the Eccentric.