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Christopher R Clarkson - One of the best experts on this subject based on the ideXlab platform.

  • Dynamic coupling of analytical Linear Flow solution and numerical fracture model for simulating early-time Flowback of fractured tight oil wells (planar fracture and complex fracture network)
    Journal of Petroleum Science and Engineering, 2019
    Co-Authors: Linsong Cheng, J. D. Williams-kovacs, Suran Wang, Christopher R Clarkson, Shijun Huang, Deqiang Wang
    Abstract:

    Abstract Quantitative analysis of Flowback data provides an early opportunity to interpret hydraulic fracture properties of fractured wells in unconventional reservoirs. In recent years, a number of studies have been dedicated to the analysis of single-phase Flow data prior to hydrocarbon breakthrough and multi-phase Flow data after hydrocarbon breakthrough during Flowback. This study provides a new model to simulate Flowback of fractured tight oil wells with planar fractures or a complex fracture network. In the model, fractures are discretized into a number of segments and the fully numerical method is used to model fracture Flow. It is assumed that the pressure interference in the matrix caused by these fracture segments can be accounted using a no-Flow boundary condition and that the drainage volumes of fracture segments form isolated regions to allow for Linear Flow from the matrix to each segment. To model this behavior, matrix Flow is simulated using the analytical transient Linear Flow solution which is dynamically coupled with the fracture Flow model by imposing continuity of pressure and flux on the fracture surfaces. The model is simple, but rigorous enough to take into account the important physics of the fracture system, including arbitrary fracture geometries and fracture conductivity distributions. The pressure and saturation gradients of each phase in fractures are accounted for. The ease of model setup and improved computational performance makes it convenient for practical application. The new model is verified with a commercial reservoir simulator. Investigation of the assumption of no-Flow boundary condition for the pressure interference in the matrix caused by the fracture segments reveals that the assumption becomes poorer with increasing matrix permeability and decreasing fracture permeability. Flow regime analysis demonstrates that, for planar fractures, water exhibits an early transient Linear Flow period (first Linear Flow in the fracture) followed by boundary-dominated Flow (first boundary-dominated Flow in the fracture) prior to hydrocarbon breakthrough, after which a second transient Linear Flow in the fracture develops. The final Flow period is boundary-dominated Flow (second boundary-dominated Flow in the fracture), indicating the end time of the Flowback period. At this stage, oil will be the dominant phase in the fracture, and will exhibit transient Linear Flow in the matrix, which is the first Flow-regime typically observed during the long-term production period. The case of a complex fracture network exhibits a similar sequence of Flow regimes. The second transient Linear Flow for this case has not been discussed in the literature. The development of this Flow period may be caused by the maintenance of fracture pressure, and decrease of water relative permeability due to hydrocarbon contribution from the matrix. A field example from western Canada exhibits the Flow regimes noted above and is history-matched successfully using the new model. The results demonstrate the practical application of the new model for deriving reservoir/fracture properties from Flowback data and for forecasting.

  • a new low permeability reservoir core analysis method based on rate transient analysis theory
    Fuel, 2019
    Co-Authors: Christopher R Clarkson, Atena Vahedian, Amin Ghanizadeh, Chengyao Song
    Abstract:

    Abstract Unconventional reservoirs such as shales (mudrocks) and coals may exhibit an ultra-low matrix permeability ( Rate-transient analysis (RTA) is a technique used to quantitatively analyze production data from wells drilled into unconventional reservoirs to extract reservoir (e.g. permeability, hydrocarbons-in-place) and hydraulic fracture (conductivity, fracture length) properties. Multi-fractured horizontal wells (MFHWs) producing from low-permeability reservoirs commonly exhibit the Flow-regime sequence of transient Linear Flow, where hydrocarbons Flow through the reservoir orthogonal to hydraulic fractures or the horizontal well, followed by boundary-dominated Flow caused by pressure interference between adjacent hydraulic fractures or wells. Transient Linear Flow may be analyzed using RTA methods to extract fracture or well-length (if permeability is known); the end of Linear Flow can be used to estimate permeability of the reservoir, and boundary-dominated Flow to estimate hydrocarbons-in-place. In this work, a new experimental procedure and set-up, applied to core plugs under stress conditions, is developed to mimic well operating conditions encountered in the field (i.e. producing from a subsurface unconventional reservoir). After injection of methane gas into one end of the core plug, and pressure stabilization, the gas is Flowed out of the same end of the core plug at constant pressure (with the aid of a backpressure regulator), and Flow rates are measured with a Flow meter. This procedure is applied to a core plug extracted from a low-permeability siltstone of the Montney Formation (western Canada). Repeated testing consistently demonstrated a transient Linear Flow period, as the gas pressure transient propagated along the core plug, followed by boundary-dominated Flow after the pressure transient reached the end of the core plug; this sequence is identical to what is commonly observed in the field. Permeability was estimated using both the slope of a square-root of time plot (a common RTA method used to analyze transient Linear Flow), and the time at the end of Linear Flow combined with the Linear Flow distance of investigation (DOI) equation. Permeability from both techniques is in good agreement (±5% for both experiments performed), providing an important redundancy to the analysis procedure. Pore volume (and hence porosity, with bulk volume known) may be estimated from the time at the end of Linear Flow and the slope of the square-root of time plot – the calculated value is in excellent agreement (±2% for both experiments performed) with that obtained from pore volume/porosity estimates using a helium pycnometer (combined with calipered dimensions). Finally, test times for the ∼0.0007 md core plug sample, after the initiation of the production phase, are on the order of only a few minutes to obtain the two independent estimates of permeability and pore volume, which is faster than that achievable from a PDP test. The new innovative experimental procedure is successful in reproducing the physics of Flow in unconventional reservoirs, with the results being analyzable with the same techniques applied to field data.

  • rate transient analysis of liquid rich tight shale reservoirs using the dynamic drainage area concept examples from north american reservoirs
    Journal of Natural Gas Science and Engineering, 2016
    Co-Authors: Farhad Qanbari, Christopher R Clarkson
    Abstract:

    Abstract The early-time performance of multi-fractured horizontal wells is mainly controlled by fracture geometry, total effective area of the fractures, and conductivity of the primary fracture system. Inverse modeling using rate-transient analysis (RTA) methods has historically been used to characterize MFHWs at different stages of well life, including the early-time performance. In particular, Linear Flow analysis is used to estimate the total effective fracture area from online production data, provided that reservoir and fluid properties are known. However, a primary complication in analytical Linear Flow analysis is the incorporation of nonLinearities such as multi-phase Flow and pressure-dependent rock/fluid properties into the calculations. A new Linear Flow analysis technique is presented in the current study, which can be applied to tight/shale systems with multi-phase Flow and pressure-dependent rock/fluid properties. The method combines three important reservoir engineering concepts for Linear Flow analysis: dynamic drainage area (DDA), material balance, and decoupling of saturation and pressure (which is analogous to the decoupling of geomechanics and fluid Flow). The DDA approach has been used previously by the authors for history-matching and forecasting using a semi-analytical model, but not for inverse modeling (RTA). The DDA concept, which uses a time-dependent well productivity index equation for the transient Flow period, facilitates the incorporation of any sort of nonLinearity (including decoupled saturation functions) and operational constraints in modeling and RTA of Linear Flow in MFHWs. The method is validated against numerical simulation and applied to various sets of field production data from tight/shale gas and oil wells with different levels of condensate- (oil-) gas ratio. For all the field cases, total effective fracture area obtained from the new analytical RTA method is in reasonable agreement with numerical modeling results. Regarding accuracy and practicality, the new method represents an improvement in RTA of liquid-rich tight/shale reservoirs, particularly for cases with multi-phase Flow and pressure-dependent rock/fluid properties. Further, the concepts used in the new model development are easy to understand and implement.

  • Transient Flow analysis and partial water relative permeability curve derivation for low permeability undersaturated coalbed methane wells
    International Journal of Coal Geology, 2015
    Co-Authors: Christopher R Clarkson, Farhad Qanbari
    Abstract:

    Abstract Rate transient analysis (RTA) is an important reservoir engineering tool used to extract reservoir and stimulation information from Flow rates and pressures obtained from producing wells. Adaptation of analytical RTA methods for this purpose has been slow for coalbed methane (CBM) reservoirs because of the complexities of multi-phase Flow, non-static absolute permeability, desorption, among others. Some progress has been made historically for high permeability CBM reservoirs, where depletion (boundary-dominated Flow) occurs quickly, however low permeability CBM reservoirs are currently being evaluated internationally (e.g. China), which brings forward additional challenges. For example, in some instances, low permeability, undersaturated CBM wells exhibit long periods of transient Flow, during which the transition from single-phase Flow of water to two-phase Flow of gas and water occurs. This behavior has not been dealt with rigorously in the development of analytical RTA methods. It is the purpose of the current work to extend RTA to apply to low-permeability, undersaturated CBM wells exhibiting this behavior. The horizontal CBM well studied in this work exhibits two periods of apparent transient Linear Flow separated by a transition, as determined from diagnostic analysis of water production data using a log–log plot of rate-normalized pressure (RNP) versus time. It is hypothesized that the well actually exhibits transient Linear Flow throughout the entire studied production period (supported by reservoir simulation) and that productivity changes leading to the apparent transition in Flow regime are caused by the combined effects of relative permeability changes after desorption pressure is reached, and (possibly) fines migration and stress-dependent permeability. In order to extend the early single-phase Linear Flow analysis of this well (occurring above desorption pressure) to the multi-phase period (below desorption pressure), the RNP half-slope trend (Linear Flow) established during the single-phase Flow period is extrapolated through the rest of the production period. An RNP ratio (RNPR) is then created by calculating the ratio of the extrapolated (corrected) RNP and the RNP of the uncorrected field data. The RNPR can then serve to correct the production data affected by multi-phase Flow (and possibly fines migration and stress dependent permeability) and hence extend the amount of data that can be used for production analysis. Further, the RNPR squared, combined with water saturation calculations, may be used to derive water relative permeability curves from the transient data. These concepts are tested using both numerical simulation and field data. The resulting field-derived water relative permeability curve can be used as a solid starting point for simulation history-matching, although it covers a limited range of water saturations. This work should be of interest to professional engineers and geoscientists involved in CBM reservoir characterization efforts. Future work will determine if these concepts are applicable to other low-permeability reservoirs exhibiting the transition from single- to multi-phase Flow during the transient Linear Flow period, such as tight oil and gas condensate reservoirs.

  • production data analysis of tight gas condensate reservoirs
    Journal of Natural Gas Science and Engineering, 2015
    Co-Authors: Hamid Behmanesh, Hamidreza Hamdi, Christopher R Clarkson
    Abstract:

    Abstract The current focus on liquids-rich shale (LRS) plays in North America underscores the need to develop reservoir engineering methods to analyze such reservoirs. Commercialization of LRS plays is now possible due to new technology, such as multi-fractured horizontal wells (MFHW). Efficient production from such reservoirs necessitates understanding of Flow mechanisms, reservoir properties and the controlling rock and fluid parameters. Production-decline analysis is an important technique for analysis of production data and obtaining estimates of recoverable reserves. Nevertheless, these techniques, developed for conventional reservoirs, are not appropriate for ultra-low permeability reservoirs. There are substantial differences in reservoir performance characteristics between conventional and ultra-low permeability reservoirs. LRS reservoirs produce much leaner wellstreams compared to conventional reservoirs due to very low permeabilities that result in very large drawdowns. Methods for analysis of two-phase Flow in conventional reservoirs, with underlying simplifying assumptions, are no longer applicable. This paper discusses production data analysis of constant Flowing bottomhole pressure (FBHP) wells producing from LRS (gas condensate) reservoirs. A theoretical basis is developed for a gas condensate reservoir during the transient matrix Linear Flow (drawdown) period. The governing Flow equation is Linearized using appropriately defined two-phase pseudopressure and pseudotime functions so that the solutions for liquids can be applied. The derived backward model is employed to compute the Linear Flow parameter, x f √ k . Simulation results show that the liquid yield will be approximately constant for LRS wells during the transient Linear Flow, from the early days of initial testing, if FBHP is almost constant. An analytical formulation is used to prove this finding for 1D transient Linear Flow of LRS wells. The proposed production data analysis (PDA) method is illustrated using simulated production data for different fluid models and relative permeability curves. Fine-grid compositional and black oil numerical models are used for this purpose.

Farhad Qanbari - One of the best experts on this subject based on the ideXlab platform.

  • rate transient analysis of liquid rich tight shale reservoirs using the dynamic drainage area concept examples from north american reservoirs
    Journal of Natural Gas Science and Engineering, 2016
    Co-Authors: Farhad Qanbari, Christopher R Clarkson
    Abstract:

    Abstract The early-time performance of multi-fractured horizontal wells is mainly controlled by fracture geometry, total effective area of the fractures, and conductivity of the primary fracture system. Inverse modeling using rate-transient analysis (RTA) methods has historically been used to characterize MFHWs at different stages of well life, including the early-time performance. In particular, Linear Flow analysis is used to estimate the total effective fracture area from online production data, provided that reservoir and fluid properties are known. However, a primary complication in analytical Linear Flow analysis is the incorporation of nonLinearities such as multi-phase Flow and pressure-dependent rock/fluid properties into the calculations. A new Linear Flow analysis technique is presented in the current study, which can be applied to tight/shale systems with multi-phase Flow and pressure-dependent rock/fluid properties. The method combines three important reservoir engineering concepts for Linear Flow analysis: dynamic drainage area (DDA), material balance, and decoupling of saturation and pressure (which is analogous to the decoupling of geomechanics and fluid Flow). The DDA approach has been used previously by the authors for history-matching and forecasting using a semi-analytical model, but not for inverse modeling (RTA). The DDA concept, which uses a time-dependent well productivity index equation for the transient Flow period, facilitates the incorporation of any sort of nonLinearity (including decoupled saturation functions) and operational constraints in modeling and RTA of Linear Flow in MFHWs. The method is validated against numerical simulation and applied to various sets of field production data from tight/shale gas and oil wells with different levels of condensate- (oil-) gas ratio. For all the field cases, total effective fracture area obtained from the new analytical RTA method is in reasonable agreement with numerical modeling results. Regarding accuracy and practicality, the new method represents an improvement in RTA of liquid-rich tight/shale reservoirs, particularly for cases with multi-phase Flow and pressure-dependent rock/fluid properties. Further, the concepts used in the new model development are easy to understand and implement.

  • Transient Flow analysis and partial water relative permeability curve derivation for low permeability undersaturated coalbed methane wells
    International Journal of Coal Geology, 2015
    Co-Authors: Christopher R Clarkson, Farhad Qanbari
    Abstract:

    Abstract Rate transient analysis (RTA) is an important reservoir engineering tool used to extract reservoir and stimulation information from Flow rates and pressures obtained from producing wells. Adaptation of analytical RTA methods for this purpose has been slow for coalbed methane (CBM) reservoirs because of the complexities of multi-phase Flow, non-static absolute permeability, desorption, among others. Some progress has been made historically for high permeability CBM reservoirs, where depletion (boundary-dominated Flow) occurs quickly, however low permeability CBM reservoirs are currently being evaluated internationally (e.g. China), which brings forward additional challenges. For example, in some instances, low permeability, undersaturated CBM wells exhibit long periods of transient Flow, during which the transition from single-phase Flow of water to two-phase Flow of gas and water occurs. This behavior has not been dealt with rigorously in the development of analytical RTA methods. It is the purpose of the current work to extend RTA to apply to low-permeability, undersaturated CBM wells exhibiting this behavior. The horizontal CBM well studied in this work exhibits two periods of apparent transient Linear Flow separated by a transition, as determined from diagnostic analysis of water production data using a log–log plot of rate-normalized pressure (RNP) versus time. It is hypothesized that the well actually exhibits transient Linear Flow throughout the entire studied production period (supported by reservoir simulation) and that productivity changes leading to the apparent transition in Flow regime are caused by the combined effects of relative permeability changes after desorption pressure is reached, and (possibly) fines migration and stress-dependent permeability. In order to extend the early single-phase Linear Flow analysis of this well (occurring above desorption pressure) to the multi-phase period (below desorption pressure), the RNP half-slope trend (Linear Flow) established during the single-phase Flow period is extrapolated through the rest of the production period. An RNP ratio (RNPR) is then created by calculating the ratio of the extrapolated (corrected) RNP and the RNP of the uncorrected field data. The RNPR can then serve to correct the production data affected by multi-phase Flow (and possibly fines migration and stress dependent permeability) and hence extend the amount of data that can be used for production analysis. Further, the RNPR squared, combined with water saturation calculations, may be used to derive water relative permeability curves from the transient data. These concepts are tested using both numerical simulation and field data. The resulting field-derived water relative permeability curve can be used as a solid starting point for simulation history-matching, although it covers a limited range of water saturations. This work should be of interest to professional engineers and geoscientists involved in CBM reservoir characterization efforts. Future work will determine if these concepts are applicable to other low-permeability reservoirs exhibiting the transition from single- to multi-phase Flow during the transient Linear Flow period, such as tight oil and gas condensate reservoirs.

  • a new method for production data analysis of tight and shale gas reservoirs during transient Linear Flow period
    Journal of Natural Gas Science and Engineering, 2013
    Co-Authors: Farhad Qanbari, Christopher R Clarkson
    Abstract:

    Abstract Pseudo-pressure has historically been used in analytical solutions of the diffusivity equation for analysis of real gas Flow in conventional gas reservoirs. The accuracy of analytical solutions during the transient Flow period is contingent on the validity of the assumption of constant hydraulic diffusivity which is implicit in the background formulations. However, the assumption of pseudo-pressure-independent hydraulic diffusivity during transient Flow is not valid for the cases of high pressure drawdown at the wellbore. For tight and shale gas reservoirs, this dependency is more pronounced due to the complexities associated with non-Darcy Flow, adsorption/desorption phenomena, stress-sensitivity of permeability and porosity, and condensation in porous media. The current study focuses on rate transient analysis of tight and shale gas reservoirs during transient Linear Flow period for a single fractured well producing under constant well bottom-hole pressure. The results of the analytical solution of real gas Flow in porous media are corrected for the effects of high pressure drawdown, non-static permeability, and condensate formation. The method proposed in this study includes three key elements: introducing a measure of nonLinearity (departure of dimensionless hydraulic diffusivity from Linearity); differential and integral formulation of the correction factor (used to correct the slope of the square-root-of-time plot); implementing the iterative integral method for solution of Flow equation; and evaluating the correction factor for constant-pressure production during transient Linear Flow period. The results show that the correction factor becomes more important for higher values of drawdown, permeability modulus, and condensate saturation.

Morteza Nobakht - One of the best experts on this subject based on the ideXlab platform.

  • analysis of production data in shale gas reservoirs rigorous corrections for fluid and Flow properties
    Journal of Natural Gas Science and Engineering, 2012
    Co-Authors: Morteza Nobakht, Christopher R Clarkson
    Abstract:

    Abstract Analysis of long-term Linear Flow periods associated with shale gas production has received much attention in recent literature as a means of obtaining information about stimulation efficiency. However, the most popular methods for analysis (ex. square-root-of-time plot) can lead to incorrect characterization. Nobakht and Clarkson (2011a) demonstrated that the square-root-of-time plot may not be a straight line for constant gas rate production Linear Flow and the non-Linear shape may lead to incorrect Flow regime identification. The square-root-of-time plot is however a straight line for constant Flowing pressure ( Nobakht and Clarkson, 2011b ). Ibrahim and Wattenbarger, 2005 , Ibrahim and Wattenbarger, 2006 and Nobakht and Clarkson (2011b) showed that using the slope of square-root-of-time plot, for constant Flowing pressure constraint, leads to an overestimation of fracture half-length. Additional important considerations for shale gas analysis are non-Darcy Flow and non-static reservoir properties. Clarkson et al. (2011) demonstrated that ignoring gas-slippage effects, thought to be important in ultra-low permeability reservoirs, can cause errors in reservoir characterization. They incorporated slippage into pseudo-variables for production data analysis, as has been done with non-static permeability ( Thompson et al., 2010 ). Finally, Nobakht et al. (2011) extended the methodology proposed by Nobakht and Clarkson (2011b) to properly analyze Linear Flow in the presence of slippage and desorption. The purpose of the current work is to evaluate the current methods for analyzing Linear Flow in shale gas reservoirs, and establish which method is the most accurate for reservoir characterization. First, recent studies addressing Linear Flow under constant Flowing pressure and constant gas rate production are briefly reviewed. Then, a comparison among the above-mentioned methods for calculating fracture half-length or contacted matrix surface area is made. It is shown that Nobakht et al. (2011) method yields the fracture half-lengths that best match the expected values for constant Flowing pressure. Finally, we present a method for analyzing Linear Flow for real production data, where neither Flowing pressure nor gas rate is constant. The method is validated using three numerically-simulated cases. It is found that this method works well for the three cases provided.

  • a new analytical method for analyzing Linear Flow in tight shale gas reservoirs constant Flowing pressure boundary condition
    Spe Reservoir Evaluation & Engineering, 2012
    Co-Authors: Morteza Nobakht, Christopher R Clarkson
    Abstract:

    Many tight/shale gas wells exhibit Linear Flow, which can last for several years. Linear Flow can be analyzed using a square-root-oftime plot, a plot of rate-normalized pressure vs. the square root of time. Linear Flow appears as a straight line on this plot, and the slope of this line can be used to calculate the product of fracture half-length and the square root of permeability. In this paper, Linear Flow from a fractured well in a tight/shale gas reservoir under a constant-Flowing-pressure constraint is studied. It is shown that the slope of the square-root-of-time plot results in an overestimation of fracture half-length, if permeability is known. The degree of this overestimation is influenced by initial pressure, Flowing pressure, and formation compressibility. An analytical method is presented to correct the slope of the squareroot-of-time plot to improve the overestimation of fracture halflength. The method is validated using a number of numerically simulated cases. As expected, the square-root-of-time plots for these simulated cases appear as a straight line during Linear Flow for constant Flowing pressure. It is found that the newly developed analytical method results in a more reliable estimate of fracture half-length, if permeability is known. Our approach, which is fully analytical, results in an improvement in Linear-Flow analysis over previously presented methods. Finally, the application of this method to multifractured horizontal wells is discussed and the method is applied to three field examples.

Ahmad Shakeel - One of the best experts on this subject based on the ideXlab platform.

  • Non-Linear Flow modes of identified particles in Pb-Pb collisions at $ \sqrt{s_{\mathrm{NN}}} $ = 5.02 TeV
    'Springer Science and Business Media LLC', 2020
    Co-Authors: Acharya Shreyasi, Adolfsson Jonatan, Adamova Dagmar, Adler Alexander, Aggarwal, Madan Mohan, Aglieri Rinella Gianluca, Agnello Michelangelo, Agrawal Neelima, Ahammed Zubayer, Ahmad Shakeel
    Abstract:

    International audienceThe p$_{T}$-differential non-Linear Flow modes, v$_{4,22}$, v$_{5,32}$, v$_{6,33}$ and v$_{6,222}$ for π$^{±}$, K$^{±}$, $ {\mathrm{K}}_{\mathrm{S}}^0 $ , p + $ \overline{\mathrm{p}} $, Λ + $ \overline{\Lambda} $ and ϕ-meson have been measured for the first time at $ \sqrt{s_{\mathrm{NN}}} $ = 5.02 TeV in Pb-Pb collisions with the ALICE detector at the Large Hadron Collider. The results were obtained with a multi-particle technique, correlating the identified hadrons with reference charged particles from a different pseudorapidity region. These non-Linear observables probe the contribution from the second and third order initial spatial anisotropy coefficients to higher Flow harmonics. All the characteristic features observed in previous p$_{T}$-differential anisotropic Flow measurements for various particle species are also present in the non-Linear Flow modes, i.e. increase of magnitude with increasing centrality percentile, mass ordering at low p$_{T}$ and particle type grouping in the intermediate p$_{T}$ range. Hydrodynamical calculations (iEBE-VISHNU) that use different initial conditions and values of shear and bulk viscosity to entropy density ratios are confronted with the data at low transverse momenta. These calculations exhibit a better agreement with the anisotropic Flow coefficients than the non-Linear Flow modes. These observations indicate that non-Linear Flow modes can provide additional discriminatory power in the study of initial conditions as well as new stringent constraints to hydrodynamical calculations.[graphic not available: see fulltext

  • Higher harmonic non-Linear Flow modes of charged hadrons in Pb-Pb collisions at $\sqrt{s_{\rm{NN}}}$ = 5.02 TeV
    'Springer Science and Business Media LLC', 2020
    Co-Authors: Acharya Shreyasi, Adolfsson Jonatan, Adamova Dagmar, Adler Alexander, Aggarwal, Madan Mohan, Aglieri Rinella Gianluca, Agnello Michelangelo, Agrawal Neelima, Ahammed Zubayer, Ahmad Shakeel
    Abstract:

    International audienceAnisotropic Flow coefficients, v$_{n}$, non-Linear Flow mode coefficients, χ$_{n,mk}$, and correlations among different symmetry planes, ρ$_{n,mk}$ are measured in Pb-Pb collisions at $ \sqrt{s_{\mathrm{NN}}} $ = 5.02 TeV. Results obtained with multi-particle correlations are reported for the transverse momentum interval 0.2 < p$_{T}$< 5.0 GeV/c within the pseudorapidity interval 0.4 < |η| < 0.8 as a function of collision centrality. The v$_{n}$ coefficients and χ$_{n,mk}$ and ρ$_{n,mk}$ are presented up to the ninth and seventh harmonic order, respectively. Calculations suggest that the correlations measured in different symmetry planes and the non-Linear Flow mode coefficients are dependent on the shear and bulk viscosity to entropy ratios of the medium created in heavy-ion collisions. The comparison between these measurements and those at lower energies and calculations from hydrodynamic models places strong constraints on the initial conditions and transport properties of the system.[graphic not available: see fulltext

  • Linear and non-Linear Flow modes of charged hadrons in Pb-Pb collisions at $\sqrt{s_{\rm{NN}}}$ = 5.02 TeV
    'Springer Science and Business Media LLC', 2020
    Co-Authors: Acharya Shreyasi, Adolfsson Jonatan, Adamova Dagmar, Adler Alexander, Aggarwal, Madan Mohan, Aglieri Rinella Gianluca, Agnello Michelangelo, Agrawal Neelima, Ahammed Zubayer, Ahmad Shakeel
    Abstract:

    International audienceAnisotropic Flow coefficients, v$_{n}$, non-Linear Flow mode coefficients, χ$_{n,mk}$, and correlations among different symmetry planes, ρ$_{n,mk}$ are measured in Pb-Pb collisions at $ \sqrt{s_{\mathrm{NN}}} $ = 5.02 TeV. Results obtained with multi-particle correlations are reported for the transverse momentum interval 0.2 < p$_{T}$< 5.0 GeV/c within the pseudorapidity interval 0.4 < |η| < 0.8 as a function of collision centrality. The v$_{n}$ coefficients and χ$_{n,mk}$ and ρ$_{n,mk}$ are presented up to the ninth and seventh harmonic order, respectively. Calculations suggest that the correlations measured in different symmetry planes and the non-Linear Flow mode coefficients are dependent on the shear and bulk viscosity to entropy ratios of the medium created in heavy-ion collisions. The comparison between these measurements and those at lower energies and calculations from hydrodynamic models places strong constraints on the initial conditions and transport properties of the system.[graphic not available: see fulltext

Acharya S. - One of the best experts on this subject based on the ideXlab platform.

  • Higher harmonic non-Linear Flow modes of charged hadrons in Pb-Pb collisions at root s(NN)=5.02 TeV
    'Springer Science and Business Media LLC', 2021
    Co-Authors: Acharya S., Adamova D., Adler A., Adolfsson J., Aggarwal M. M., Agnello M., Agrawal N., Ahammed Z., Rinella G. A., Ahmad S.
    Abstract:

    CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFINANCIADORA DE ESTUDOS E PROJETOS - FINEPFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPAnisotropic Flow coefficients, nu(n), non-Linear Flow mode coefficients, chi(n,mk), and correlations among different symmetry planes, rho(n,mk) are measured in Pb-Pb collisions at root s(NN) = 5.02TeV. Results obtained with multi-particle correlations are5133CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFINANCIADORA DE ESTUDOS E PROJETOS - FINEPFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPCONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFINANCIADORA DE ESTUDOS E PROJETOS - FINEPFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPSem informaçãoSem informaçãoSem informaçãoThe ALICE Collaboration would like to thank all its engineers and technicians for their invaluable contributions to the construction of the experiment and the CERN accelerator teams for the outstanding performance of the LHC complex. The ALICE Collaborat

  • Non-Linear Flow modes of identified particles in Pb-Pb collisions at √sNN = 5.02 TeV
    'Springer Science and Business Media LLC', 2020
    Co-Authors: Acharya S., Antičić Tome, Erhardt Filip, Gotovac Sven, Jerčić Marko, Lončar Petra, Mudnić Eugen, Planinić Mirko, Poljak Nikola, Simatović Goran
    Abstract:

    The pT-differential non-Linear Flow modes, v4,22, v5,32, v6,33 and v6,222 for π ±, K±, K0 S, p + p, Λ + Λ and φ-meson have been measured for the first time at √sNN = 5.02 TeV in Pb-Pb collisions with the ALICE detector at the Large Hadron Collider. The results were obtained with a multi-particle technique, correlating the identified hadrons with reference charged particles from a different pseudorapidity region. These non-Linear observables probe the contribution from the second and third order initial spatial anisotropy coefficients to higher Flow harmonics. All the characteristic features observed in previous pT-differential anisotropic Flow measurements for various particle species are also present in the non-Linear Flow modes, i.e. increase of magnitude with increasing centrality percentile, mass ordering at low pT and particle type grouping in the intermediate pT range. Hydrodynamical calculations (iEBE-VISHNU) that use different initial conditions and values of shear and bulk viscosity to entropy density ratios are confronted with the data at low transverse momenta. These calculations exhibit a better agreement with the anisotropic Flow coefficients than the non-Linear Flow modes. These observations indicate that non-Linear Flow modes can provide additional discriminatory power in the study of initial conditions as well as new stringent constraints to hydrodynamical calculations

  • Non-Linear Flow modes of identified particles in Pb-Pb collisions at √sNN = 5.02 TeV
    'Springer Science and Business Media LLC', 2020
    Co-Authors: Acharya S., Adolfsson Jonatan, Christiansen Peter, Matonoha Oliver, Nassirpour Adrian, Ohlson Alice, Oskarsson Anders, Richert Tuva, Vazquez Rueda Omar, Silvermyr David
    Abstract:

    The pT-differential non-Linear Flow modes, v4,22, v5,32, v6,33 and v6,222 for π±, K±, KS0 , p + p ¯ , Λ + Λ ¯ and ϕ-meson have been measured for the first time at sNN = 5.02 TeV in Pb-Pb collisions with the ALICE detector at the Large Hadron Collider. The results were obtained with a multi-particle technique, correlating the identified hadrons with reference charged particles from a different pseudorapidity region. These non-Linear observables probe the contribution from the second and third order initial spatial anisotropy coefficients to higher Flow harmonics. All the characteristic features observed in previous pT-differential anisotropic Flow measurements for various particle species are also present in the non-Linear Flow modes, i.e. increase of magnitude with increasing centrality percentile, mass ordering at low pT and particle type grouping in the intermediate pT range. Hydrodynamical calculations (iEBE-VISHNU) that use different initial conditions and values of shear and bulk viscosity to entropy density ratios are confronted with the data at low transverse momenta. These calculations exhibit a better agreement with the anisotropic Flow coefficients than the non-Linear Flow modes. These observations indicate that non-Linear Flow modes can provide additional discriminatory power in the study of initial conditions as well as new stringent constraints to hydrodynamical calculations. [Figure not available: see fulltext.]. © 2020, The Author(s)

  • Higher harmonic non-Linear Flow modes of charged hadrons in Pb-Pb collisions at √sNN = 5.02 TeV
    'Springer Science and Business Media LLC', 2020
    Co-Authors: Acharya S., Adolfsson Jonatan, Christiansen Peter, Matonoha Oliver, Nassirpour Adrian, Ohlson Alice, Oskarsson Anders, Richert Tuva, Vazquez Rueda Omar, Silvermyr David
    Abstract:

    Anisotropic Flow coefficients, vn, non-Linear Flow mode coefficients, χn,mk, and correlations among different symmetry planes, ρn,mk are measured in Pb-Pb collisions at sNN = 5.02 TeV. Results obtained with multi-particle correlations are reported for the transverse momentum interval 0.2 < pT< 5.0 GeV/c within the pseudorapidity interval 0.4 < |η| < 0.8 as a function of collision centrality. The vn coefficients and χn,mk and ρn,mk are presented up to the ninth and seventh harmonic order, respectively. Calculations suggest that the correlations measured in different symmetry planes and the non-Linear Flow mode coefficients are dependent on the shear and bulk viscosity to entropy ratios of the medium created in heavy-ion collisions. The comparison between these measurements and those at lower energies and calculations from hydrodynamic models places strong constraints on the initial conditions and transport properties of the system

  • Higher harmonic non-Linear Flow modes of charged hadrons in Pb-Pb collisions at √sNN = 5.02 TeV
    'Springer Science and Business Media LLC', 2020
    Co-Authors: Acharya S., Adamova D., Adler A., Adolfsson J., Aggarwal M. M., Aglieri Rinella G., Agnello M., Agrawal N., Ahammed Z., Ahmad S.
    Abstract:

    Anisotropic Flow coefficients, vn, non-Linear Flow mode coefficients, \u3c7n,mk, and correlations among different symmetry planes, \u3c1n,mk are measured in Pb-Pb collisions at sNN = 5.02 TeV. Results obtained with multi-particle correlations are reported for the transverse momentum interval 0.2 < pT< 5.0 GeV/c within the pseudorapidity interval 0.4 < |\u3b7| < 0.8 as a function of collision centrality. The vn coefficients and \u3c7n,mk and \u3c1n,mk are presented up to the ninth and seventh harmonic order, respectively. Calculations suggest that the correlations measured in different symmetry planes and the non-Linear Flow mode coefficients are dependent on the shear and bulk viscosity to entropy ratios of the medium created in heavy-ion collisions. The comparison between these measurements and those at lower energies and calculations from hydrodynamic models places strong constraints on the initial conditions and transport properties of the system. [Figure not available: see fulltext.]