scholarly journals Study on Competitive Adsorption and Displacing Properties of CO2 Enhanced Shale Gas Recovery: Advances and Challenges

Geofluids ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Shuyang Liu ◽  
Baojiang Sun ◽  
Jianchun Xu ◽  
Hangyu Li ◽  
Xiaopu Wang
Keyword(s):  
Shale Gas ◽  
Adsorption Mechanism ◽  
Competitive Adsorption ◽  
Gas Adsorption ◽  
Organic Matter Content ◽  
Gas Production ◽  
Gas Recovery ◽  
Model Studies ◽  
Displacement Experiments ◽  
Adsorption Of Co2

CO2 enhanced shale gas recovery (CO2-ESGR) draws worldwide attentions in recent years with having significant environmental benefit of CO2 geological storage and economic benefit of shale gas production. This paper is aimed at reviewing the state of experiment and model studies on gas adsorption, competitive adsorption of CO2/CH4, and displacement of CO2-CH4 in shale in the process of CO2-ESGR and pointing out the related challenges and opportunities. Gas adsorption mechanism in shale, influencing factors (organic matter content, kerogen type, thermal maturity, inorganic compositions, moisture, and micro/nano-scale pore), and adsorption models are described in this work. The competitive adsorption mechanisms are qualitatively ascertained by analysis of unique molecular and supercritical properties of CO2 and the interaction of CO2 with shale matrix. Shale matrix shows a stronger affinity with CO2, and thus, adsorption capacity of CO2 is larger than that of CH4 even with the coexistence of CO2-CH4 mixture. Displacement experiments of CO2-CH4 in shale proved that shale gas recovery is enhanced by the competitive adsorption of CO2 to CH4. Although the competitive adsorption mechanism is preliminary revealed, some challenges still exist. Competitive adsorption behavior is not fully understood in the coexistence of CO2 and CH4 components, and more experiment and model studies on adsorption of CO2-CH4 mixtures need to be conducted under field conditions. Coupling of competitive adsorption with displacing flow is key factor for CO2-ESGR but not comprehensively studied. More displacement experiments of CO2-CH4 in shale are required for revealing the mechanism of flow and transport of gas in CO2-ESGR.

Study on the Forming Conditions of Shale Gas in Coal Measure of Wuli Area, Qinghai Province, China

2013 ◽  
Vol 295-298 ◽  
pp. 2770-2773 ◽  
Author(s):  
Dai Yong Cao ◽  
Jing Li ◽  
Ying Chun Wei ◽  
Xiao Yu Zhang ◽  
Chong Jing Wang
Keyword(s):  
Shale Gas ◽  
Thermal Evolution ◽  
Organic Matter Content ◽  
Gas Production ◽  
Matter Content ◽  
Source Rocks ◽  
Coal Measure ◽  
Gas Generation ◽  
Qinghai Province ◽  
Coal Measures

Besides coal seam, the source rocks including dark mudstone, carbon mudstone and so on account for a large proportion in the coal measures. Based on the complex geothermal evolution history, the majority of coal measure organic matters with the peak of gas generation have a good potential of gas. Therefore, shale gas in coal measure is an important part of the shale gas resources. There are good conditions including the thickness of coal measures, high proportion of shale rocks, rich in organic matter content, high degree of thermal evolution, high content of brittle mineral and good conditions of the porosity and permeability for the generation of shale gas in Wuli area, the south of Qinghai province. Also the direct evidence of the gas production has been obtained from the borehole. The evaluation of shale gas in coal measure resources could broaden the understanding of the shale gas resources and promote the comprehensive development of the coal resources.

scholarly journals Molecular Investigation on the Displacement Characteristics of CH4 by CO2, N2 and Their Mixture in a Composite Shale Model

Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 2
Author(s):  
Liang Gong ◽  
Yuan Zhang ◽  
Na Li ◽  
Ze-Kai Gu ◽  
Bin Ding ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Shale Gas ◽  
Injection Pressure ◽  
Gas Production ◽  
Formation Temperature ◽  
Displacement Efficiency ◽  
Gas Recovery ◽  
Displacement Capacity ◽  
Molecular Investigation ◽  
Shale Reservoirs

The rapid growth in energy consumption and environmental pollution have greatly stimulated the exploration and utilization of shale gas. The injection of gases such as CO2, N2, and their mixture is currently regarded as one of the most effective ways to enhance gas recovery from shale reservoirs. In this study, molecular simulations were conducted on a kaolinite–kerogen IID composite shale matrix to explore the displacement characteristics of CH4 using different injection gases, including CO2, N2, and their mixture. The results show that when the injection pressure was lower than 10 MPa, increasing the injection pressure improved the displacement capacity of CH4 by CO2. Correspondingly, an increase of formation temperature also increased the displacement efficiency of CH4, but an increase of pore size slightly increased this displacement efficiency. Moreover, it was found that when the proportion of CO2 and N2 was 1:1, the displacement efficiency of CH4 was the highest, which proved that the simultaneous injection of CO2 and N2 had a synergistic effect on shale gas production. The results of this paper will provide guidance and reference for the displacement exploitation of shale gas by injection gases.

Analysis of Effective Porosity and Effective Permeability in Shale-Gas Reservoirs With Consideration of Gas Adsorption and Stress Effects

SPE Journal ◽  
2017 ◽  
Vol 22 (06) ◽  
pp. 1739-1759 ◽  
Author(s):  
Y.. Pang ◽  
M. Y. Soliman ◽  
H.. Deng ◽  
Hossein Emadi
Keyword(s):  
Pore Pressure ◽  
Shale Gas ◽  
Gas Adsorption ◽  
Effective Porosity ◽  
Gas Production ◽  
Gas Reservoirs ◽  
Adsorption Effect ◽  
Shale Gas Reservoirs ◽  
Porosity And Permeability ◽  
Stress Dependent

Summary Nanoscale porosity and permeability play important roles in the characterization of shale-gas reservoirs and predicting shale-gas-production behavior. The gas adsorption and stress effects are two crucial parameters that should be considered in shale rocks. Although stress-dependent porosity and permeability models have been introduced and applied to calculate effective porosity and permeability, the adsorption effect specified as pore volume (PV) occupied by adsorbate is not properly accounted. Generally, gas adsorption results in significant reduction of nanoscale porosity and permeability in shale-gas reservoirs because the PV is occupied by layers of adsorbed-gas molecules. In this paper, correlations of effective porosity and permeability with the consideration of combining effects of gas adsorption and stress are developed for shale. For the adsorption effect, methane-adsorption capacity of shale rocks is measured on five shale-core samples in the laboratory by use of the gravimetric method. Methane-adsorption capacity is evaluated through performing regression analysis on Gibbs adsorption data from experimental measurements by use of the modified Dubinin-Astakhov (D-A) equation (Sakurovs et al. 2007) under the supercritical condition, from which the density of adsorbate is found. In addition, the Gibbs adsorption data are converted to absolute adsorption data to determine the volume of adsorbate. Furthermore, the stress-dependent porosity and permeability are calculated by use of McKee correlations (McKee et al. 1988) with the experimentally measured constant pore compressibility by use of the nonadsorptive-gas-expansion method. The developed correlations illustrating the changes in porosity and permeability with pore pressure in shale are similar to those produced by the Shi and Durucan model (2005), which represents the decline of porosity and permeability with the increase of pore pressure in the coalbed. The tendency of porosity and permeability change is the inverse of the common stress-dependent regulation that porosity and permeability increase with the increase of pore pressure. Here, the gas-adsorption effect has a larger influence on PV than stress effect does, which is because more gas is attempting to adsorb on the surface of the matrix as pore pressure increases. Furthermore, the developed correlations are added into a numerical-simulation model at field scale, which successfully matches production data from a horizontal well with multistage hydraulic fractures in the Barnett Shale reservoir. The simulation results note that without considering the effect of PV occupied by adsorbed gas, characterization of reservoir properties and prediction of gas production by history matching cannot be performed reliably. The purpose of this study is to introduce a model to calculate the volume of the adsorbed phase through the adsorption isotherm and propose correlations of effective porosity and permeability in shale rocks, including the consideration of the effects of both gas adsorption and stress. In addition, practical application of the developed correlations to reservoir-simulation work might achieve an appropriate evaluation of effective porosity and permeability and provide an accurate estimation of gas production in shale-gas reservoirs.

Characterization of CO2/CH4 Competitive Adsorption in Various Clay Minerals in Relation to Shale Gas Recovery from Molecular Simulation

2019 ◽  
Vol 33 (9) ◽  
pp. 8202-8214 ◽  
Author(s):  
Xiaofei Hu ◽  
Hucheng Deng ◽  
Chang Lu ◽  
Yuanyuan Tian ◽  
Zhehui Jin
Keyword(s):  
Clay Minerals ◽  
Molecular Simulation ◽  
Shale Gas ◽  
Competitive Adsorption ◽  
Gas Recovery

Impact of gas adsorption on apparent permeability of shale fracture and shale gas recovery rate

2018 ◽  
Vol 48 (8) ◽  
pp. 891-900
Author(s):  
HongYan QU ◽  
Yan PENG ◽  
JiShan LIU ◽  
ZhangXing CHEN ◽  
KeLiu WU ◽  
...  
Keyword(s):  
Shale Gas ◽  
Recovery Rate ◽  
Gas Adsorption ◽  
Apparent Permeability ◽  
Gas Recovery ◽  
Shale Fracture

scholarly journals Thermodynamics and Kinetics of CO2/CH4 Adsorption on Shale from China: Measurements and Modeling

Energies ◽  
2019 ◽  
Vol 12 (6) ◽  
pp. 978 ◽  
Author(s):  
Yuan Chi ◽  
Changzhong Zhao ◽  
Junchen Lv ◽  
Jiafei Zhao ◽  
Yi Zhang
Keyword(s):  
Partial Pressure ◽  
Shale Gas ◽  
Competitive Adsorption ◽  
Co2 Adsorption ◽  
Displacement Effect ◽  
Gas Recovery ◽  
Thermodynamics And Kinetics ◽  
Adsorption Behaviors ◽  
Ch4 Adsorption ◽  
Kinetics Of

CO2-enhanced shale gas recovery (CO2-ESGR) sequestrates anthropogenic CO2 and improves the profitability of shale gas exploitation. This work investigated the adsorption behaviors of CO2 and CH4 on shale from China at 20, 40, 60 and 80 °C. The pressure ranges for CO2 and CH4 were 1–5 and 1–15 MPa, respectively. The excess adsorbed amount of CH4 increased with increasing pressure from the beginning to the end, while the maximum excess CO2 adsorption was observed at approximately 4 MPa. The absolute average deviations (AADs) of CO2 and CH4, determined by the Langmuir + k model, were 2.12–3.10% and 0.88–1.11%, respectively. Relatively good adsorptivity for CO2 was exhibited when the pressure was less than 5 MPa, which was beneficial to the implementation of CO2-ESGR. With continuous increases in pressure, the adsorption capacity of CO2 was weaker than that of CH4, suggesting that the injected CO2 would reduce the partial pressure of CH4 for CO2-ESGR and the displacement effect would no longer be significant. In addition, the adsorption rate of CO2 was much faster than that of CH4. CO2 was more active in the competitive adsorption and it was advantageous to the efficiency of CO2-ESGR.

Probabilistic Estimation of Shale Gas Reserves Implementing Fast Marching Method and Monte Carlo Simulation

2016 ◽  
Author(s):  
Jaejun Kim ◽  
Joe M. Kang ◽  
Yongjun Park ◽  
Seojin Lim ◽  
Changhyup Park ◽  
...  
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Shale Gas ◽  
Computing Time ◽  
Gas Production ◽  
Full Scale ◽  
Fast Marching Method ◽  
Fast Marching ◽  
Gas Recovery ◽  
Marching Method

This paper evaluates the estimated ultimate recovery for 10-year operation at a shale gas reservoir, implementing FMM (Fast Marching Method) as a surrogate model of full-scale numerical simulation and Monte Carlo simulation as a tool for accessing the uncertainty of FMM-based proxy parameters. Sensitivity analysis shows the significant properties affecting the gas recovery that are enhanced permeability, matrix permeability, and porosity in sequence. Using the statistical distributions of these parameters, this study determines P10, P50, and P90 of the 10-year cumulative gas production and compares them with the values from full-physics simulations. The computing time based on the proxy model is much smaller than that of the full-scale simulations while the prediction accuracy is acceptable. FMM can forecast the production profiles reliably without time-consuming simulation and the integration of Monte-Carlo simulation is able to evaluate the uncertainty of gas recovery, quantitatively.

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