scholarly journals Increase liquid oil production by huff-n-puff of produced gas in shale gas condensate reservoirs

2015 ◽  
Vol 11 ◽  
pp. 19-26 ◽  
Author(s):  
James J. Sheng
2020 ◽  
Vol 185 ◽  
pp. 106566
Author(s):  
Sadegh Dahim ◽  
Amin Taghavinejad ◽  
Milad Razghandi ◽  
Hamed Rahimi Rigi ◽  
Kianoosh Moeini ◽  
...  

SPE Journal ◽  
2021 ◽  
pp. 1-13
Author(s):  
Sheng Luo ◽  
Fangxuan Chen ◽  
Dengen Zhou ◽  
Hadi Nasrabadi

Summary In shale gas-condensate reservoirs, when the initial reservoir pressure is greater than the dewpoint pressure, the condensate/gas ratio (CGR) has been observed to decrease continuously as the pressure drops to less than the initial reservoir pressure. This abnormal behavior cannot be explained with conventional pressure/volume/temperature (PVT) models that ignore the presence of nanopores in shale rock. Herein, for the first time, we present a study that provides a physical explanation for the observed CGR trends by including the effect of nanopores on the fluid phase behavior and depletion of shale gas-condensate reservoirs. Our model uses multiscale PVT simulation by means of a pore-size-dependent equation of state (EOS). Two lean gas-condensate cases (shallow and deep reservoirs) are investigated. The simulation results show that hydrocarbons distribute heterogeneously with respect to pore size on the nanoscale. There are more intermediate to heavy hydrocarbons (C3–11+) but fewer light ends (C1–2) distributed in the nanopores than in the bulk region. At the end of depletion, because of confinement effects, large amounts of intermediate hydrocarbons are trapped in the nanopores, causing condensate recovery loss. Multiscale depletion simulations suggest that a decreasing CGR can occur at the beginning of production when the reservoir pressure is higher than the dewpoint pressure. Such behavior is caused by the nanopore depletion in the shale matrix, which is a process of selectively releasing light hydrocarbon components. We also present a novel approach to model the nonequilibrium fluid distribution between the fracture and nanopores using a simple local-equilibrium concept. Our results indicate that the nonequilibrium fluid distribution increases the CGR drop because of the compositional selectivity of the nanopore in favor of intermediate and heavy hydrocarbons.


Author(s):  
Reza Ganjdanesh ◽  
Wei Yu ◽  
Mauricio Xavier Fiallos ◽  
Erich Kerr ◽  
Kamy Sepehrnoori ◽  
...  

2012 ◽  
Vol 616-618 ◽  
pp. 796-803
Author(s):  
Wen Ge Hu ◽  
Xiang Fang Li ◽  
Xin Zhou Yang ◽  
Ke Liu Wu ◽  
Jun Tai Shi

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.


2015 ◽  
Author(s):  
Reza Ganjdanesh ◽  
Mohsen Rezaveisi ◽  
Gary A. Pope ◽  
Kamy Sepehrnoori

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