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Kamy Sepehrnoori - One of the best experts on this subject based on the ideXlab platform.
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Production forecasting of Gas Condensate well considering fluid phase behavior in the reservoir and wellbore
Journal of Natural Gas Science and Engineering, 2015Co-Authors: Jun Tai Shi, Liang Huang, Kamy SepehrnooriAbstract:Abstract Retrograde condensation occurs when the reservoir pressure falls below the dew point pressure in Gas Condensate reservoirs. Complex fluid phase behavior in the reservoir and the wellbore makes it challenging to predict the productivity of Gas Condensate wells. To date, the Gas rate in the deliverability equation of Gas well is assumed the Gas rate at surface condition converted from that at the reservoir condition by using the volume factor. However, because of the complex fluid phase behavior in Gas Condensate wells, the Gas rate at the reservoir condition cannot be directly changed to that at surface condition by using volume factor. Hence, the development of a new analytical model to accurately calculate the productivity of Gas Condensate wells is still required and necessary. In this work, we propose a new deliverability equation of Gas Condensate wells with a consideration of fluid phase behavior in both the reservoir and the wellbore. Also, several pseudo-pressure functions for different Condensate distribution and flow models are examined systematically; these include the model before condensation, the model after condensation, but without Condensate flow, the model after condensation and with Condensate flow, and the model after re-vaporization. Two synthetic numerical simulation cases and two field case studies are performed to validate these deliverability equations for Gas Condensate wells. Results show that the phase behavior of Gas Condensate fluid in the wellbore plays a significant role in the deliverability evaluation and in the forecasting of Gas Condensate wells. If neglecting its effect on the deliverability, Gas and Condensate production rates could not be accurately predicted. The data from the proposed model have good agreement with the simulation and field production data of wells in Yakela Gas Condensate Reservoir and Yaha Gas Condensate Reservoir in China. If the conventional deliverability equation neglecting the effect of phase behavior in the wellbore was used, the predicted Gas production will be higher than the actual value; even 50% higher than the actual value at high flow rates. Through these case studies, it can be concluded that the effect of Condensate-Gas phase behavior in the wellbore cannot be ignored in the deliverability equation for Gas Condensate wells. This work can provide a more accurate method of forecasting the Gas and Condensate production for Condensate Gas reservoirs and also guide optimization of single well production rate and Gas recovery rate for Gas Condensate reservoirs.
Wang Hai - One of the best experts on this subject based on the ideXlab platform.
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comparison and development of predictive models for dew point pressure of Gas Condensate reservoir fluids
Natural Gas Geoscience, 2013Co-Authors: Wang HaiAbstract:The exploitation of Gas Condensate reservoir needs accurate phase behavior data,especially the dew point pressures of Gas Condensate reservoir fluid.By considering the characteristics of Gas Condensate reservoirs and analyzing the merits and demerits of the existing correlations in literatures for dew point pressures,a new empirical model for predicting the dew point pressures of Gas Condensate reservoirs was developed,which involving the parameters of the reservoir temperature,Gas composition,and C7 plus component properties.Fourteen groups of Gas Condensate samples from different areas in China were selected to examine the applicability of this new correlation by comparing with several other correlations and thermodynamic models.The results show that the total average absolute deviation of this new developed model is only 1.24%,much better than those calculated by other methods in literatures.The new model also has a wide application range,with methane composition of 65.59%-93.09% and Gas-oil ratio for Gas Condensate reservoir of 1 002-63 377m3/m3.
Zhu Yin-xia - One of the best experts on this subject based on the ideXlab platform.
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DELIVERABILITY TESTING METHOD OF Gas Condensate WELLS WITH HIGH Condensate CONTENT AND ITS APPLICATION
Natural Gas Geoscience, 2007Co-Authors: Zhu Yin-xiaAbstract:Aiming at the problems in the process of the stabilized well test of Gas Condensate wells with high Condensate content,the flexibility of stabilized test in this kind of wells is analyzed based on the withdrawal characteristics of Gas Condensate reservoirs.A well test method adapted to Gas Condensate wells with high Condensate content is put forward,which takes the well production characteristics into consideration.The field conduct of the method shows that the modified isochronal testing method can eliminate the effects of retrograde condensation on test results and obtain precise testing results,providing the foundation for reasonable production proration.
Jun Tai Shi - One of the best experts on this subject based on the ideXlab platform.
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Production forecasting of Gas Condensate well considering fluid phase behavior in the reservoir and wellbore
Journal of Natural Gas Science and Engineering, 2015Co-Authors: Jun Tai Shi, Liang Huang, Kamy SepehrnooriAbstract:Abstract Retrograde condensation occurs when the reservoir pressure falls below the dew point pressure in Gas Condensate reservoirs. Complex fluid phase behavior in the reservoir and the wellbore makes it challenging to predict the productivity of Gas Condensate wells. To date, the Gas rate in the deliverability equation of Gas well is assumed the Gas rate at surface condition converted from that at the reservoir condition by using the volume factor. However, because of the complex fluid phase behavior in Gas Condensate wells, the Gas rate at the reservoir condition cannot be directly changed to that at surface condition by using volume factor. Hence, the development of a new analytical model to accurately calculate the productivity of Gas Condensate wells is still required and necessary. In this work, we propose a new deliverability equation of Gas Condensate wells with a consideration of fluid phase behavior in both the reservoir and the wellbore. Also, several pseudo-pressure functions for different Condensate distribution and flow models are examined systematically; these include the model before condensation, the model after condensation, but without Condensate flow, the model after condensation and with Condensate flow, and the model after re-vaporization. Two synthetic numerical simulation cases and two field case studies are performed to validate these deliverability equations for Gas Condensate wells. Results show that the phase behavior of Gas Condensate fluid in the wellbore plays a significant role in the deliverability evaluation and in the forecasting of Gas Condensate wells. If neglecting its effect on the deliverability, Gas and Condensate production rates could not be accurately predicted. The data from the proposed model have good agreement with the simulation and field production data of wells in Yakela Gas Condensate Reservoir and Yaha Gas Condensate Reservoir in China. If the conventional deliverability equation neglecting the effect of phase behavior in the wellbore was used, the predicted Gas production will be higher than the actual value; even 50% higher than the actual value at high flow rates. Through these case studies, it can be concluded that the effect of Condensate-Gas phase behavior in the wellbore cannot be ignored in the deliverability equation for Gas Condensate wells. This work can provide a more accurate method of forecasting the Gas and Condensate production for Condensate Gas reservoirs and also guide optimization of single well production rate and Gas recovery rate for Gas Condensate reservoirs.
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Energy Control in the Depletion of Gas Condensate Reservoirs with Different Permeabilities
Advanced Materials Research, 2012Co-Authors: Xin Zhou Yang, Jun Tai ShiAbstract:Energy control (i. e. pressure control) has an obvious effect on development effect in the depletion of Gas Condensate reservoir. Phase change behavior and characteristics of the relative pemeability in Gas Condensate reservoirs were displayed in this paper, then pressure and Condensate distribution were showed through reservoir simulation. Finally, the influence of the pressure drop on Condensate distribution and Condensate oil production in Gas Condensate reservoirs with different permeabilities was studied. Results show that: First, in high / moderate permeability Gas Condensate reservoirs, the pressure and the Condensate blocking will extend to further reservoir, while the pressure and Condensate just appear in the vicinity of wellbore in low permeability Gas Condensate reservoirs. Second, the influence of pressure drop on Condensate distribution in high permeability Gas Condensate reservoirs is obvious, the Condensate blocking extends with the increasing of the pressure drop, and Condensate extent can be controlled by optimizing a rational pressure drop, while the influence is inconspicuous in low permeability Gas Condensate reservoirs. Third, the influence of pressure drop on Condensate oil production in high / moderate permeability Gas Condensate reservoirs is conspicuous, a rational pressure drop exists, while the influence is indistinct in low permeability or tight Gas Condensate reservoirs, before the retrograde condensation, a low pressure drop should be adopted in a long term until the bottom hole flowing pressure drops below the dew point pressure, when the Condensate blocking forms, well stimulation is advised before developing by pressure control.
Sayed Ali Mousavi Dehghani - One of the best experts on this subject based on the ideXlab platform.
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Gas/Condensate production decline analysis using type curves
International Journal of Oil Gas and Coal Technology, 2017Co-Authors: Mohammad Taghizadeh Sarvestani, Fariborz Rashidi, Sayed Ali Mousavi DehghaniAbstract:Abnormal thermodynamic behaviour and multi-phase flow of Gas/Condensate reservoirs restrict the application of available production models to analyse production data in order to estimate reservoir properties. This study aims at development of a new analytical model to estimate initial Gas-in-place, average reservoir pressure, drainage area size, permeability, and well skin from multi-phase Gas/Condensate production data via type curves. For this purpose, the governing flow equation of multi-phase Gas/Condensate reservoir is derived and by employing novel two-phase pseudo-functions, a general boundary dominated flow solution is developed for variable bottom-hole pressure/rate conditions. The effects of positive coupling and negative inertia in the near-wellbore region are also included in the formulation. Subsequently, the obtained production model is presented in type curve analysis format by using new dimensionless parameters. The proposed model is validated using different synthetic compositional models by changing different reservoir and fluid properties including reservoir fluid types, relative permeability data, and production history mode. In addition, the method is evaluated using actual field data. Results show that the proposed method estimates the reservoir properties quite well for all cases. [Received: December 1, 2014; Accepted: October 6, 2015]
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Gas/Condensate variable rate reservoir limits testing
Journal of Natural Gas Science and Engineering, 2015Co-Authors: Mohammad Taghizadeh Sarvestani, Fariborz Rashidi, Sayed Ali Mousavi DehghaniAbstract:Abstract Production analysis models incorporating appropriate transport mechanisms in porous media are helpful elements in the estimation of reservoir parameters (e.g. hydrocarbon in place, average reservoir pressure, skin, and permeability) using usual and inexpensive production data. Due to different thermodynamic and flow behavior of Gas/Condensate reservoir, the multi-phase production data of such reservoir cannot be accurately analyzed using single-phase dry Gas models. This study presents a novel analytical model to estimate initial Gas-in-place, average reservoir pressure, drainage area size and shape from boundary dominated multi-phase production data in Gas/Condensate reservoirs. For this purpose, the governing flow equation of multi-phase Gas/Condensate reservoirs was derived and linearized using new two-phase pseudo-functions and the boundary dominated flow solution was developed for variable bottom-hole pressure/rate conditions in any bounded Gas/Condensate reservoirs. The new equation was coupled with a material balance equation and formed a new Gas/Condensate production analysis model. An important feature of the proposed method is that it forms a linear plot so that by using its slope and intercept, the desired estimates of reservoir properties could be determined. The proposed model is validated by different fine-grid compositional simulation models by changing different reservoir and fluid properties including different reservoir fluid types, relative permeability data, reservoir geometry, and production history mode. Results of this study are compared with the results of numerical simulation models and error analyses are performed. Results show that the proposed method estimates the reservoir properties quite well for all models and all errors are within engineering practices.
