CO2 injection to enhanced gas recovery in depleted gas reservoir

To gain a better understanding of the enhanced shale gas recovery by CO2 gas injection (CO2-ESGR) technique, the dynamic displacement mechanism of CO2–CH4, the CO2 enhanced shale gas recovery (RCH4), and CO2 storage capacity (VCO2) were studied based on transport properties of CO2 and CH4. Experiments of CO2 injection into shale gas reservoir preadsorbed by CH4 were performed in a fixed bed. Breakthrough curves were obtained under different test conditions and simulated by one-dimension advection-dispersion (AD) model. It was found that dispersion coefficient (K1) rather than molecular diffusivity of CO2 dominated its transport in shale. K1 together with advection velocity (υ) of CO2 during CH4 displacement controls RCH4 and VCO2. When transporting in shale gas reservoir, CO2 had larger dynamic adsorption amount and υ, but smaller K1 than CH4. The competitive transport and adsorption behavior of CO2 and CH4 made it possible for CO2 to store in shale reservoir and to drive the in-place CH4 out of shale reservoir. The transfer zone of CO2–CH4 displacement (CCD) was very wide. High RCH4 and VCO2 were reached at low injection CO2 gas pressure and for small shale particles. Higher injection flow rates of CO2 and temperatures ranging from 298 K to 338 K had a little effect on RCH4 and VCO2. For field conditions, high CO2 injection pressure has to be used because the pore pressure of shale reservoir and adsorption amount of CH4 increase with the increase in depth of shale gas reservoir, but RCH4 is still not high.

Download Full-text

Time-lapse seismic monitoring of CO2 injection into a depleted gas reservoir—Naylor Field, Australia

The Leading Edge ◽

10.1190/1.3304819 ◽

2010 ◽

Vol 29 (2) ◽

pp. 164-169 ◽

Cited By ~ 27

Author(s):

Milovan Urosevic ◽

Roman Pevzner ◽

Anton Kepic ◽

Putri Wisman ◽

Valeria Shulakova ◽

...

Keyword(s):

Time Lapse ◽

Seismic Monitoring ◽

Co2 Injection ◽

Gas Reservoir ◽

Depleted Gas Reservoir

Download Full-text

ESTIMATION OF TECHNOLOGICAL EFFICIENCY OF WORK AND SHUTDOWN OF PRODUCTION WELLS WITH NITROGEN INJECTION INTO THE DEPLETED GAS RESERVOIR

Prospecting and Development of Oil and Gas Fields ◽

10.31471/1993-9973-2018-3(68)-7-11 ◽

2018 ◽

pp. 7-11

Author(s):

R. M. Kondrat ◽

L. I. Khaidarova

Keyword(s):

Group Program ◽

Gas Reservoir ◽

Gas Recovery ◽

Nitrogen Injection ◽

Technological Efficiency ◽

Modeling Group ◽

Production Wells ◽

Residual Gas ◽

Composite Modeling ◽

Depleted Gas Reservoir

The main directions of increasing hydrocarbon output from depleted gas deposits and possible options of injecting nitrogen into the reservoir are described. For the conditions of a depleted hypothetical gas reservoir, a mathematical modeling of the process of displacement of the residual gas by nitrogen using the composite modeling module GEM, which is part of the CMG (Computer Modeling Group) program, was performed. Based on the results of the research, the effect on the gas recovery factor for the residual gas and other technical indicators was established on the development of the work and production wells shut-down zone when nitrogen was injected into the deposit with different time periods.

Download Full-text

THE EFFECT OF THE CYCLICAL NITROGEN INJECTION ON THE FINAL COEFFICIENT OF GAS RECOVERY AT DIFFERENT RATES IN THE DEPLETED GAS RESERVOIR

Prospecting and Development of Oil and Gas Fields ◽

10.31471/1993-9973-2018-4(69)-15-22 ◽

2018 ◽

pp. 15-22

Author(s):

R. M. Kondrat ◽

L. I. Khaidarova

Keyword(s):

Gas Production ◽

Reservoir Pressure ◽

Hydrocarbon Gases ◽

Gas Reservoir ◽

Recovery Coefficient ◽

Research Results ◽

Gas Recovery ◽

Nitrogen Injection ◽

Residual Gas ◽

Depleted Gas Reservoir

The application of non-hydrocarbon gases with the aim of displacing residual gas from depleted fields is substantiated. Mathematical modeling is carried out of the process of residual gas displacing with nitrogen in the GEM compositional simulating module under the conditions of a hypothetical gas reservoir of circular shape. The said module is a part of the licensed CMG computer program. The effect of the cyclical nature of the aquifer injection nitrogen into depleted gas reservoir at different rates till the final gas recovery coefficient for residual gas is developed. The study concerns different durations of nitrogen injection cycles into the reservoir (6, 12, 18, 24, 30, and 36 months) and various correlations of the rates of nitrogen injection and gas production in reservoir conditions of 1:1; 1.5:1; 2:1. During the nitrogen injection into the reservoir, the output wells stopped; whereas after surcease of the nitrogen injection, they were again exploited until the reservoir pressure reached to 0.1 Pprimary. Then the process of cyclic nitrogen injection into the layer continued, until nitrogen break through into the producing wells and its content in the produced products reached 5% vol. The research results were processed in the form of graphical dependencies of reservoir pressure, gas flow rate and gas recovery coefficient for residual gas at the end of the cycle of nitrogen injection into the reservoir as a function of the number of such cycles. The research results indicate a significant effect on the gas recovery coefficient for the residual gas of the duration of the cycle of nitrogen injection into the reservoir and the ratio of rates of nitrogen injection and gas production, with an increase in which the coefficient of gas output gradually decreases. According to the research results, the optimal parameters of the process of nitrogen injection into the reservoir should be chosen on the basis of technological results, as well as technical and economic calculations.

Download Full-text