The Experts below are selected from a list of 21651 Experts worldwide ranked by ideXlab platform
Moe Key - One of the best experts on this subject based on the ideXlab platform.
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Prediction of Water Breakthrough Time in Low Permeability Gas Reservoirs with Bottom Water in Consideration of Threshold Pressure
Petroleum Drilling Techniques, 2012Co-Authors: Moe KeyAbstract:Because of the threshold pressure,the performance of water coning in low permeability Gas Reservoir with bottom water is quite different from that of conventional Gas Reservoir with bottom water.Therefore,there is a big gap between the actual performance and the calculated water breakthrough time based on conventional prediction formula.This paper established a water conning model for Gas Reservoir with bottom water:the Gas layer was opened partly in Gas wells,Gas flows in radial flow form inside the perforation section,and combined with radial flow and semispherical flow below the perforation section.According to this model,it is assumed that the Reservoir has horizontal,homogeneous,isotropic layers with equal thickness,water displaces Gas in a way of piston-type,the viscosity and density of water and Gas are constant,the pressure gradient at the interface of water and Gas is the same,and the gravity and the capillary pressure can be neglected.Based on the assumption,the prediction formula of the water breakthrough time has been derived by considering threshold pressure gradient in low permeability Gas Reservoir with bottom water.Comparing the result calculated by this formula with that of Sobocinski-Cornelius formula,the formula calculation results more close to the real value,and we conclude that the water breakthrough time is reduced with the increase of threshold pressure gradient.
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Experimental study on factors of KlinKenberg permeability in low permeable Gas Reservoir
2012Co-Authors: Moe KeyAbstract:CNPC found a Low-Permeability Gas Reservoir with CO2 in Jilin oil fields.Because the rock properties and fluid properties are unique,it is not accurate to analysis the effects of Gas slippage effect on KlinKenberg permeability and penetration capacity.In view of this specificity,they are determined and analyzed by single-phase Gas flow laboratory experiments.Experimental studies show that the KlinKenberg effect is found in the Gas flow process in core and the influence factors are important including the core type,confining pressure,Gas type and temperature.The KlinKenberg permeability of porosity core is higher than that of micro-fracture core.With the increasing of confining pressure,the slop of permeability-mean pressure curve is not changed,but the KlinKenberg permeability and its amplitude are decreased.Because of the different molecular weights,the KlinKenberg permeability of carbon dioxide (big molecular weight) is higher than that of natural Gas and nitrogen Gas (small molecular weight).The influence of temperature on Gas flow at low temperature is greater than that at high temperature,that is,the KlinKenberg permeability of 20℃ is higher than that of 50,80 and 140℃.
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the establishment of deliverability equation considering variable threshold pressure drop in low permeability Gas Reservoir
Petroleum Drilling Techniques, 2010Co-Authors: Moe KeyAbstract:It has been verified and accepted that there is a threshold pressure gradient(TPG) in low permeable Gas Reservoirs.At present,the deliverability equations for low permeable Gas Reservoirs were developed by assuming that TPG is constant and not related with productivity.Applications show that current equation has remarkable errors.Based on non-Darcy steady flow equation,it shows that the additional pressure drop is not a constant and is related with production rate.The error of the current deliverability equation was analyzed using modified isochronal well testing as an example.The new deliverability equation was obtained through integration.The corresponding modifications for modified isochronal well testing were provided.The new deliverability equation is useful.
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the establishment of deliverability equation with consideration of variable threshold pressure drop in low permeability Gas Reservoir
Well Testing, 2010Co-Authors: Moe KeyAbstract:The percolation mechanism in low permeability Gas Reservoir is different from that in common Gas Reservoirs.All the deliverability equations regard the additional pressure drop as constant,but this is not true in the former cases.Based on the low-speed and non-Darcy steady flow equation for low permeability Gas Reservoir,this paper derives an expression of threshold pressure drop,concludes that the additional pressure drop is not a constant,and has something to do with the production rate during testing;gets a new deliverability equation which takes variable threshold pressure drop into account,and provides the relevant processing method of the modified isochronal test data.Field application showed that the new deliverability equation is practically useful.
Catalin Teodoriu - One of the best experts on this subject based on the ideXlab platform.
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Modeling fully transient two-phase flow in the near-wellbore region during liquid loading in Gas wells
Journal of Natural Gas Science and Engineering, 2010Co-Authors: He Zhang, Gioia Falcone, Catalin TeodoriuAbstract:Abstract In oil and Gas field operations, the dynamic interactions between Reservoir and wellbore cannot be ignored, especially during transient flow in the near-wellbore region. A particular instance of transient flow in the near-wellbore region is the intermittent response of a Reservoir that is typical of liquid loading in Gas wells. Despite the high level of attention that the industry has devoted to the alleviation of liquid loading, the fundamental understanding of the associated phenomena is still surprisingly weak. This applies not only to the flows in the wells, but also to the ways in which these flows interact with those in the Reservoir. This paper presents the results of a numerical modeling effort using bespoke code written at Texas A&M University, to identify the pressure profile in the near-wellbore region during fully transient flow conditions for a synthetic, low permeability Gas Reservoir. The results show a “U-shaped” pressure profile along the Reservoir radius in the near-wellbore region. The existence of such pressure profile might explain the re-injection of the heavier liquid phase into the Reservoir during liquid unloading in Gas wells. A comparison of the results with those obtained using a commercial Reservoir simulator show the limitations of the latter, which is unable to mimic re-injection of the liquid into the near-wellbore region.
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Relative Permeability Hysteresis Effects in the Near-Wellbore Region During Liquid Loading in Gas Wells
SPE Latin American and Caribbean Petroleum Engineering Conference, 2010Co-Authors: He Zhang, Gioia Falcone, Catalin TeodoriuAbstract:In oil and Gas field operations, the dynamic interactions between Reservoir and wellbore cannot be ignored, especially during transient flow in the near-wellbore region. A particular instance of transient flow in the near-wellbore region is the intermittent response of a Reservoir that is typical of liquid loading in Gas wells. Our previous numerical simulation study (Zhang et. al. 2009 and 2010) successfully captured the liquid backflow rates resulting from bottomhole pressure (BHP) oscillations typical of liquid loading, and emphasized their detrimental effect on Gas production. This paper presents a numerical modeling effort to investigate the relative permeability hysteresis effects in the near-wellbore region during transient flow conditions for a synthetic, low permeability Gas Reservoir. Firstly, the previously validated "U-shaped?? pressure profile along the Reservoir radius was generated with an increased BHP from a starting steady-state flowing configuration. This pressure profile can lead to reinjection of the liquid phase into the Reservoir. The BHP was then let to decrease, with a corresponding temporary recovery in Gas productivity. With subsequent BHP oscillations, the flow direction was allowed to switch back and forth, which could represent a typical liquid loading scenario. The Killough method was used to calculate the relative permeability hysteresis during the various imbibitions and drainage processes. The results reveal that the hysteresis effect is negligible at a high-frequency alternation of imbibition and drainage in the near-wellbore region, and may therefore not be significant in liquid loading problems.
Hazim N. Dmour - One of the best experts on this subject based on the ideXlab platform.
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Practical Well Test Analysis of a Hydraulically Fractured Low Permeability Gas Reservoir: A Case History
Journal of King Saud University - Engineering Sciences, 2008Co-Authors: Hazim N. DmourAbstract:Abstract The primary objective of hydraulic fracturing is to create a propped fracture with sufficient conductivity and length to amplify or at least optimize well performance of low permeability tight Gas Reservoir. The oil industry has suggested that hydraulically fractured tight Gas wells performance is hindered significantly by non-Darcy flow effect. This work will present an investigation of non-Darcy flow effect to hydraulically fractured Gas wells performance and provide the development, validation, and application of actual well test analysis for wells with a finite conductivity vertical fracture. Also, this work presents the results obtained in the study of actual post frac modified isochronal test data of Gas wells intersected by a finite conductivity vertical fracture in a tight low permeability Gas Reservoir. In addition, the estimation of Reservoir properties and fracture properties were carried out to construct a simple analytical model, which used for rate prediction. The effect of non-Darcy flow in fractures is clearly seen in the tests data and will lead to limiting production especially on higher chokes (after one inch). Therefore, non-Darcy effects should be considered in design of hydraulic fracture treatments, otherwise the design might be far from optimal
Zheng Li-kun - One of the best experts on this subject based on the ideXlab platform.
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Establishment of Trinomial Productivity Equation for Non-Darcy Effect Low Permeability Gas Reservoirs
Natural Gas Geoscience, 2013Co-Authors: Zheng Li-kunAbstract:The Gas percolation is not adherence to Darcy′s law due to existence of starting pressure gradient in the low permeability Gas Reservoir.Based on low permeability Gas Reservoir with non-Darcy low-velocity seepage differential equation,I establish the low permeability Gas Reservoir Trinomial equation with consideration of starting pressure gradient effect,and present the solving method.The proposed method is feasible and reliable calculation results after the crude data are calculated in a Gas Reservoir.
He Zhang - One of the best experts on this subject based on the ideXlab platform.
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Modeling fully transient two-phase flow in the near-wellbore region during liquid loading in Gas wells
Journal of Natural Gas Science and Engineering, 2010Co-Authors: He Zhang, Gioia Falcone, Catalin TeodoriuAbstract:Abstract In oil and Gas field operations, the dynamic interactions between Reservoir and wellbore cannot be ignored, especially during transient flow in the near-wellbore region. A particular instance of transient flow in the near-wellbore region is the intermittent response of a Reservoir that is typical of liquid loading in Gas wells. Despite the high level of attention that the industry has devoted to the alleviation of liquid loading, the fundamental understanding of the associated phenomena is still surprisingly weak. This applies not only to the flows in the wells, but also to the ways in which these flows interact with those in the Reservoir. This paper presents the results of a numerical modeling effort using bespoke code written at Texas A&M University, to identify the pressure profile in the near-wellbore region during fully transient flow conditions for a synthetic, low permeability Gas Reservoir. The results show a “U-shaped” pressure profile along the Reservoir radius in the near-wellbore region. The existence of such pressure profile might explain the re-injection of the heavier liquid phase into the Reservoir during liquid unloading in Gas wells. A comparison of the results with those obtained using a commercial Reservoir simulator show the limitations of the latter, which is unable to mimic re-injection of the liquid into the near-wellbore region.
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Relative Permeability Hysteresis Effects in the Near-Wellbore Region During Liquid Loading in Gas Wells
SPE Latin American and Caribbean Petroleum Engineering Conference, 2010Co-Authors: He Zhang, Gioia Falcone, Catalin TeodoriuAbstract:In oil and Gas field operations, the dynamic interactions between Reservoir and wellbore cannot be ignored, especially during transient flow in the near-wellbore region. A particular instance of transient flow in the near-wellbore region is the intermittent response of a Reservoir that is typical of liquid loading in Gas wells. Our previous numerical simulation study (Zhang et. al. 2009 and 2010) successfully captured the liquid backflow rates resulting from bottomhole pressure (BHP) oscillations typical of liquid loading, and emphasized their detrimental effect on Gas production. This paper presents a numerical modeling effort to investigate the relative permeability hysteresis effects in the near-wellbore region during transient flow conditions for a synthetic, low permeability Gas Reservoir. Firstly, the previously validated "U-shaped?? pressure profile along the Reservoir radius was generated with an increased BHP from a starting steady-state flowing configuration. This pressure profile can lead to reinjection of the liquid phase into the Reservoir. The BHP was then let to decrease, with a corresponding temporary recovery in Gas productivity. With subsequent BHP oscillations, the flow direction was allowed to switch back and forth, which could represent a typical liquid loading scenario. The Killough method was used to calculate the relative permeability hysteresis during the various imbibitions and drainage processes. The results reveal that the hysteresis effect is negligible at a high-frequency alternation of imbibition and drainage in the near-wellbore region, and may therefore not be significant in liquid loading problems.
