The Experts below are selected from a list of 96 Experts worldwide ranked by ideXlab platform
Maccalman Laura - One of the best experts on this subject based on the ideXlab platform.
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Effects of genetic testing on insurance : pedigree analysis and ascertainment adjustment
'Heriot-Watt University', 2009Co-Authors: Maccalman LauraAbstract:Gas condensate flow, which is very different from the conventional two-phase (oil and gas) flow, shows more complicated behaviour around the Wellbore owing to condensate buildup and the different velocity effects on relative permeability (kr) of these low IFT fluid systems. This is especially true for complex Wellbore completions, such as hydraulically fractured or perforated wells. This research programme has two separate parts. The first part is about gas condensate flow around hydraulically fractured wells (HFWs). In this part of the study, different inhouse simulators have been developed by the author. These simulators account for the changes in fluid properties with pressure, phase change, coupling (increase in kr as IFT decreases or velocity increases) and inertia (decrease in kr when velocity increases) when it is required to do so. The simulators have been used to investigate the effect of different important geometrical and flow parameters on the performance of a HFW. The new developed formulae for accurate estimation of effective fracture conductivity, fracture skin factors (mechanical and flow) and effective Wellbore Radius are the main practical outcomes of this part of the study. The author has also provided a new convenient method for the optimization of fracture dimensions for a given fracture volume, in gas condensate reservoirs. The second part of this research is about the study of gas condensate flow around perforated wells. Here the previously developed simulators by the Gas Condensate Research group have been used to develop a new method for estimation of mechanical perforation skin. The introduction of a method for calculation of effective Wellbore Radius of a perforated well by which the flow skin is negligible is another important result of this part. The new formulae introduced in this work can be used as a useful tool for estimation of well productivity/injectivity. They are also very useful in reservoir simulation, because having the effective Wellbore Radius for a complex Wellbore geometry- such as a perforated well or hydraulically fractured well - provides an opportunity to define a simple open-hole system instead of the real Wellbore. This eliminates the need for a costly and cumbersome fine grid exercise, which otherwise would be required to capture accurately the variation of flow parameters around these types of Wellbores.Wellcome Trus
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Effects of genetic testing on insurance : pedigree analysis and ascertainment adjustment
2009Co-Authors: Macdonald Angus, Maccalman LauraAbstract:Gas condensate flow, which is very different from the conventional two-phase (oil and gas) flow, shows more complicated behaviour around the Wellbore owing to condensate buildup and the different velocity effects on relative permeability (kr) of these low IFT fluid systems. This is especially true for complex Wellbore completions, such as hydraulically fractured or perforated wells. This research programme has two separate parts. The first part is about gas condensate flow around hydraulically fractured wells (HFWs). In this part of the study, different inhouse simulators have been developed by the author. These simulators account for the changes in fluid properties with pressure, phase change, coupling (increase in kr as IFT decreases or velocity increases) and inertia (decrease in kr when velocity increases) when it is required to do so. The simulators have been used to investigate the effect of different important geometrical and flow parameters on the performance of a HFW. The new developed formulae for accurate estimation of effective fracture conductivity, fracture skin factors (mechanical and flow) and effective Wellbore Radius are the main practical outcomes of this part of the study. The author has also provided a new convenient method for the optimization of fracture dimensions for a given fracture volume, in gas condensate reservoirs. The second part of this research is about the study of gas condensate flow around perforated wells. Here the previously developed simulators by the Gas Condensate Research group have been used to develop a new method for estimation of mechanical perforation skin. The introduction of a method for calculation of effective Wellbore Radius of a perforated well by which the flow skin is negligible is another important result of this part. The new formulae introduced in this work can be used as a useful tool for estimation of well productivity/injectivity. They are also very useful in reservoir simulation, because having the effective Wellbore Radius for a complex Wellbore geometry- such as a perforated well or hydraulically fractured well - provides an opportunity to define a simple open-hole system instead of the real Wellbore. This eliminates the need for a costly and cumbersome fine grid exercise, which otherwise would be required to capture accurately the variation of flow parameters around these types of Wellbores.EThOS - Electronic Theses Online ServiceWellcome TrustGBUnited Kingdo
Ilmo Kukkonen - One of the best experts on this subject based on the ideXlab platform.
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Prospects for Assessing Enhanced Geothermal System (EGS) Basement Rock Flow Stimulation by Wellbore Temperature Data
Energies, 2017Co-Authors: Peter Leary, Peter Malin, Tero Saarno, Ilmo KukkonenAbstract:We use Matlab 3D finite element fluid flow/transport modelling to simulate localized Wellbore temperature events of order 0.05–0.1 °C logged in Fennoscandia basement rock at ~1.5 km depths. The temperature events are approximated as steady-state heat transport due to fluid draining from the crust into the Wellbore via naturally occurring fracture-connectivity structures. Flow simulation is based on the empirics of spatially-correlated fracture-connectivity fluid flow widely attested by well-log, well-core, and well-production data. Matching model Wellbore-centric radial temperature profiles to a 2D analytic expression for steady-state radial heat transport with Peclet number Pe ≡ r0φv0/D (r0 = Wellbore Radius, v0 = Darcy velocity at r0, φ = ambient porosity, D = rock-water thermal diffusivity), gives Pe ~ 10–15 for fracture-connectivity flow intersecting the well, and Pe ~ 0 for ambient crust. Darcy flow for model Pe ~ 10 at Radius ~10 m from the Wellbore gives permeability estimate κ ~ 0.02 Darcy for flow driven by differential fluid pressure between least principal crustal stress pore pressure and hydrostatic Wellbore pressure. Model temperature event flow permeability κm ~ 0.02 Darcy is related to well-core ambient permeability κ ~ 1 µDarcy by empirical poroperm relation κm ~ κ exp(αmφ) for φ ~ 0.01 and αm ~ 1000. Our modelling of OTN1 Wellbore temperature events helps assess the prospect of reactivating fossilized fracture-connectivity flow for EGS permeability stimulation of basement rock.
Mahdiyar Hojjat - One of the best experts on this subject based on the ideXlab platform.
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Gas condensate flow around hydraulically fractured/perforated wells
'Heriot-Watt University', 2009Co-Authors: Mahdiyar HojjatAbstract:Gas condensate flow, which is very different from the conventional two-phase (oil and gas) flow, shows more complicated behaviour around the Wellbore owing to condensate buildup and the different velocity effects on relative permeability (kr) of these low IFT fluid systems. This is especially true for complex Wellbore completions, such as hydraulically fractured or perforated wells. This research programme has two separate parts. The first part is about gas condensate flow around hydraulically fractured wells (HFWs). In this part of the study, different inhouse simulators have been developed by the author. These simulators account for the changes in fluid properties with pressure, phase change, coupling (increase in kr as IFT decreases or velocity increases) and inertia (decrease in kr when velocity increases) when it is required to do so. The simulators have been used to investigate the effect of different important geometrical and flow parameters on the performance of a HFW. The new developed formulae for accurate estimation of effective fracture conductivity, fracture skin factors (mechanical and flow) and effective Wellbore Radius are the main practical outcomes of this part of the study. The author has also provided a new convenient method for the optimization of fracture dimensions for a given fracture volume, in gas condensate reservoirs. The second part of this research is about the study of gas condensate flow around perforated wells. Here the previously developed simulators by the Gas Condensate Research group have been used to develop a new method for estimation of mechanical perforation skin. The introduction of a method for calculation of effective Wellbore Radius of a perforated well by which the flow skin is negligible is another important result of this part. The new formulae introduced in this work can be used as a useful tool for estimation of well productivity/injectivity. They are also very useful in reservoir simulation, because having the effective Wellbore Radius for a complex Wellbore geometry- such as a perforated well or hydraulically fractured well - provides an opportunity to define a simple open-hole system instead of the real Wellbore. This eliminates the need for a costly and cumbersome fine grid exercise, which otherwise would be required to capture accurately the variation of flow parameters around these types of Wellbores
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Gas condensate flow around hydraulically fractured/perforated wells
2009Co-Authors: Jamiolahmady Mahmoud, Mahdiyar HojjatAbstract:Gas condensate flow, which is very different from the conventional two-phase (oil and gas) flow, shows more complicated behaviour around the Wellbore owing to condensate buildup and the different velocity effects on relative permeability (kr) of these low IFT fluid systems. This is especially true for complex Wellbore completions, such as hydraulically fractured or perforated wells. This research programme has two separate parts. The first part is about gas condensate flow around hydraulically fractured wells (HFWs). In this part of the study, different inhouse simulators have been developed by the author. These simulators account for the changes in fluid properties with pressure, phase change, coupling (increase in kr as IFT decreases or velocity increases) and inertia (decrease in kr when velocity increases) when it is required to do so. The simulators have been used to investigate the effect of different important geometrical and flow parameters on the performance of a HFW. The new developed formulae for accurate estimation of effective fracture conductivity, fracture skin factors (mechanical and flow) and effective Wellbore Radius are the main practical outcomes of this part of the study. The author has also provided a new convenient method for the optimization of fracture dimensions for a given fracture volume, in gas condensate reservoirs. The second part of this research is about the study of gas condensate flow around perforated wells. Here the previously developed simulators by the Gas Condensate Research group have been used to develop a new method for estimation of mechanical perforation skin. The introduction of a method for calculation of effective Wellbore Radius of a perforated well by which the flow skin is negligible is another important result of this part. The new formulae introduced in this work can be used as a useful tool for estimation of well productivity/injectivity. They are also very useful in reservoir simulation, because having the effective Wellbore Radius for a complex Wellbore geometry- such as a perforated well or hydraulically fractured well - provides an opportunity to define a simple open-hole system instead of the real Wellbore. This eliminates the need for a costly and cumbersome fine grid exercise, which otherwise would be required to capture accurately the variation of flow parameters around these types of Wellbores.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
J Leveinen - One of the best experts on this subject based on the ideXlab platform.
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composite model with fractional flow dimensions for well test analysis in fractured rocks
Journal of Hydrology, 2000Co-Authors: J LeveinenAbstract:Abstract The represented analytical model is addressed to fracture-zone aquifers in which well test responses can be commonly matched with models involving fractional flow dimensions. The model assumes a composite structure representing the fractures opening into the pumping well and the fracture system comprising the actual aquifer. The aim is to assess the hydraulic properties for the near-well zone and the aquifer in terms of concrete parameters even if flow dimensions have fractional values. Dimensionless drawdown in pumping and observation wells was solved by applying Laplace transforms. The early-time approximation for the pumping well can be used to assess the transmissivity ( T 1 ) if the flow dimension in the inner zone ( n 1 ) is greater than about 1.7. The long-time solutions indicate that the inner zone induces a pseudo-skin effect that can be estimated by comparing the pumping well and observation well data. If K 1 is known, the extent of the inner zone ( r ′) can be estimated from the pseudo-skin factor. The responses tend to form log–log straight lines with slopes of 1− n 2 . By plotting drawdown vs. t (1− n 2 ) on the double-logarithmic scale, the product of the hydraulic conductivity and the through-flow area at the Wellbore Radius ( KA 2 ) and the hydraulic diffusivity ( D 2 ) of the aquifer can be estimated from the slope and the intercept. The hydraulic conductivity of the aquifer ( K 2 ) is estimated by considering the through-flow area as a projection of an n 2 -dimensional sphere with a Radius of r wb through three-dimensional space by an amount r ′ (3− n 2 ) . The analyzed field example comprises a pumping test of a fracture zone aquifer in south–central Finland. For the pumping well, simultaneous matching of drawdown and derivative type-curves with observed responses can be used to verify the results of the early-time analysis and the proposed straight-line procedure. In addition, type-curve matching yields estimates of the hydraulic diffusivity ratio and a value of the dimensionless Wellbore storage. The analyzed observation wells are considered to be sufficiently far from the inner zone. Consequently, type-curves are produced based on the dimensionless drawdown solution that is identical to generalized radial flow model. Type-curve matching of the observation well responses produces estimates for KA 2 , K 2 and D 2 . The obtained values are similar to previous studies that included models relying on integer flow dimensions. However, models relying on the fractional flow dimensions are capable to simulate the observed responses more accurately.
Liao Hongmei - One of the best experts on this subject based on the ideXlab platform.
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Effective Wellbore Radius and Typical Curve Characteristics of Well Test Analysis:Non-Newtonian Power-law Fluids
2010Co-Authors: Liao HongmeiAbstract:Among numerous tertiary recovery technologies, Alkaline -Surfactant -Polymer (ASP) flooding is one of the most important Enhanced Oil Recovery (EOR) methods. In this method, the ASP solution system exhibits the characteristics of non-Newtonian power-law fluid. A well test model with consideration of storage and skin effects is established in this paper based on non-Newtonian power-law fluid in infinite, constant pressure and no-flow circular boundary homogeneous reservoirs. The effective Wellbore Radius was obtained by introducing the dimensionless definitions of the effective Wellbore Radius and integrating parameters. Theoretical curves were obtained and further analyzed. In addition, the expressions of the early-time storage stage and the late-time radial flow phase were simplified, with two analytic solutions being derived by Laplace transformation. The results show that the early -time response stage is influenced by the combined parameter of storage and skin and the radial flow stage is affected by the power-law index for the homogeneous well test curve. The proposed model can provide a theoretical foundation for well test data analysis of ASP flooding.