Water distribution characteristic and effect on methane adsorption capacity in shale clay

Li, Jing; Li, Xiangfang; Wang, Xiangzeng; Li, Yingying; Wu, Keliu; Shi, Juntai; Liu, Yang; Feng, Dong; Zhang, Tao; Yu, Peimin

doi:10.1016/j.coal.2016.03.012

Cited by 285 publications

(241 citation statements)

References 64 publications

Supporting

Mentioning

223

Contrasting

Unclassified

Order By: Relevance

“…The results showed that the conclusion regarding gas adsorption was similar to that of previous research. However, in terms of the difference between experimental and simulation results, the authors proposed that the phase equilibrium between gas and water under different conditions should be considered [38,39]. Botan et al used microporous carbon materials to replace the organic structure of shale and coal and simulated the separation process and the permeability of natural gas.…”

Section: Introductionmentioning

confidence: 99%

Study on the Adsorption, Diffusion and Permeation Selectivity of Shale Gas in Organics

Wang

Liu

et al. 2017

Energies

View full text Add to dashboard Cite

Abstract:As kerogen is the main organic component in shale, the adsorption capacity, diffusion and permeability of the gas in kerogen plays an important role in shale gas production. Based on the molecular model of type II kerogen, an organic nanoporous structure was established. The Grand Canonical Monte Carlo (GCMC) and Molecular Dynamics (MD) methods were used to study the adsorption and diffusion capacity of mixed gas systems with different mole ratios of CO 2 and CH 4 in the foregoing nanoporous structure, and gas adsorption, isosteric heats of adsorption and self-diffusion coefficient were obtained. The selective permeation of gas components in the organic pores was further studied. The results show that CO 2 and CH 4 present physical adsorption in the organic nanopores. The adsorption capacity of CO 2 is larger than that of CH 4 in organic pores, but the self-diffusion coefficient of CH 4 in mixed gas is larger than that of CO 2 . Moreover, the self-diffusion coefficient in the horizontal direction is larger than that in the vertical direction. The mixed gas pressure and mole ratio have limited effects on the isosteric heat and the self-diffusion of CH 4 and CO 2 adsorption. Regarding the analysis of mixed gas selective permeation, it is concluded that the adsorption selectivity of CO 2 is larger than that of CH 4 in the organic nanopores. The larger the CO 2 /CH 4 mole ratio, the greater the adsorption and permeation selectivity of mixed gas in shale. The permeation process is mainly controlled by adsorption rather than diffusion. These results are expected to reveal the adsorption and diffusion mechanism of gas in shale organics, which has a great significance for further research.

show abstract

Section: Introductionmentioning

confidence: 99%

Study on the Adsorption, Diffusion and Permeation Selectivity of Shale Gas in Organics

Wang

Liu

et al. 2017

Energies

View full text Add to dashboard Cite

show abstract

“…The surface area acquired by the BET was determined based on the number of molecules deposited as a monolayer [30]. In this analysis, the effect of ice-water expansion and the evaporation of bound water can be neglected according to previous study [14]. In addition to that, a FE-SEM (model, Supra 55VP, Zeiss, Seri Iskandar Perak, Malaysia) was used to evaluate the pore samples for an untreated sample and a sample which had been treated in water for two days.…”

Section: Pore System Characteristicsmentioning

confidence: 99%

“…We employed low pressure N 2 adsorption (ASAP, model ASAP 2020, Micrometrics, Seri Iskandar, Perak, Malaysia) to evaluate the pore size distribution (PSD) and specific surface area (SSA) alteration of raw moisture equilibrated and treated immersed samples in crushed samples whose grain size <0.2 mm. The samples were pretreated by conducting outgassing at 25 • C room temperature for 10 minutes, only to remove any adsorbed gases while maintaining the moisture and water in the pores [14]. Then, the samples were immersed in liquid nitrogen to perform the low pressure N 2 adsorption at −196 • C temperature.…”

Section: Pore System Characteristicsmentioning

confidence: 99%

“…Consequently, it is highly advisable to consider the initial water content when evaluating a shale gas system [13]. The Standard Test Method for Equilibrium Moisture of Coal at 96 to 97 Percent Relative Humidity and 30C-ASTM D 1412-93-is the recommended and most commonly used procedure to simulate the water presence under unconventional reservoirs conditions [13][14][15]26]. The procedure includes placing a pre-weighted shale sample in a desiccator with a moisturizing agent that provides 97% to 98% Relative Humidity (K2SO4), and the weight difference over the time was observed.…”

Section: Shale Samples Preparationsmentioning

confidence: 99%

“…To simulate a more realistic condition of a shale gas reservoir in terms of initial water content, we adapted The Standard Test Method for Equilibrium Moisture of Coal at 96 to 97 Percent Relative Humidity and 30C (ASTM D 1412-93), which has commonly been used in previous studies [13][14][15]. After placing the shale samples in a desiccator with a humidifier agent until equilibrium was achieved, the moist sample was then measured and moisture uptake was calculated in weight percentage.…”

Section: Water Uptakementioning

confidence: 99%

See 2 more Smart Citations

Influence of Water Immersion on Pore System and Methane Desorption of Shales: A Case Study of Batu Gajah and Kroh Shale Formations in Malaysia

et al. 2018

View full text Add to dashboard Cite

Abstract:The influence of water on the pore system and gas desorption in shale remains an open question that is not yet fully understood. In this study, we present the effect of water on the shale pore system and recovered desorbed gas through a series of measurements on shale samples. We utilized the Brunauer-Emmett-Teller (BET) low pressure N 2 adsorption and Field Emission Scanning Electron Microscopy (FE-SEM) to observe and analyze the effects of water immersion and moisture on the pore system of shale samples from Batu Gajah (BG) and Kroh shale formations in Malaysia. The impact of water on desorption was then measured using the United States former Bureau of Mines (USBM) modified method. The results showed that the micropore and mesopore volumes of the Batu Gajah (BG) and Kroh (KH) shale samples were reduced by 64.84% and 44.12%, respectively, after the samples were immersed in water. The BET-specific surface area declined by 88.34% and 59.63% for the BG and KH sample, respectively. Desorption results showed that the methane desorbed volume was (KH: 1.22 cc/g, BG: 0.94 cc/g) for the water immersed sample, and (KH: 0.72 cc/g, BG: 0.60) for the equilibrated sample. The difference can be attributed to the proportion of the organic (total organic carbon) and inorganic (clay) content found in the two shale samples. The total organic carbon (TOC) existing in the KH sample was 12.1 wt %, which was greater than the organic carbon content of the BG sample (2.1 wt %). The clay content was found to be more dominant in the BG shale when compared to the KH shale.

show abstract

Water Saturation Relations and Their Diffusion‐Limited Equilibration in Gas Shale: Implications for Gas Flow in Unconventional Reservoirs

Tokunaga

Shen

Wan

et al. 2017

Water Resources Research

View full text Add to dashboard Cite

Large volumes of water are used for hydraulic fracturing of low permeability shale reservoirs to stimulate gas production, with most of the water remaining unrecovered and distributed in a poorly understood manner within stimulated regions. Because water partitioning into shale pores controls gas release, we measured the water saturation dependence on relative humidity (rh) and capillary pressure (Pc) for imbibition (adsorption) as well as drainage (desorption) on samples of Woodford Shale. Experiments and modeling of water vapor adsorption into shale laminae at rh = 0.31 demonstrated that long times are needed to characterize equilibrium in larger (5 mm thick) pieces of shales, and yielded effective diffusion coefficients from 9 × 10−9 to 3 × 10−8 m2 s−1, similar in magnitude to the literature values for typical low porosity and low permeability rocks. Most of the experiments, conducted at 50°C on crushed shale grains in order to facilitate rapid equilibration, showed significant saturation hysteresis, and that very large Pc (∼1 MPa) are required to drain the shales. These results quantify the severity of the water blocking problem, and suggest that gas production from unconventional reservoirs is largely associated with stimulated regions that have had little or no exposure to injected water. Gravity drainage of water from fractures residing above horizontal wells reconciles gas production in the presence of largely unrecovered injected water, and is discussed in the broader context of unsaturated flow in fractures.

show abstract

Water distribution characteristic and effect on methane adsorption capacity in shale clay

Cited by 285 publications

References 64 publications

Study on the Adsorption, Diffusion and Permeation Selectivity of Shale Gas in Organics

Study on the Adsorption, Diffusion and Permeation Selectivity of Shale Gas in Organics

Influence of Water Immersion on Pore System and Methane Desorption of Shales: A Case Study of Batu Gajah and Kroh Shale Formations in Malaysia

Water Saturation Relations and Their Diffusion‐Limited Equilibration in Gas Shale: Implications for Gas Flow in Unconventional Reservoirs

Contact Info

Product

Resources

About