Theory, technology and prospects of conventional and unconventional natural gas

Zou, Caineng; Yang, Zhi; He, Dengfa; Wei, Yunsheng; Li, Jian; Jia, Ailin; Chen, Jianjun; Zhao, Qun; Li, Yilong; Li, Jun; Shen, Yang

doi:10.1016/s1876-3804(18)30066-1

Cited by 241 publications

(100 citation statements)

References 8 publications

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“…This suggests that pore throat size is the most significant factor in WPT damage. 3. Calculations indicate that water film thickness was in the 21.22-38.18 nm range, and the reduced effective gas flow channel was between 20.20 and 45.15 nm after WPT.…”

Section: Discussionmentioning

confidence: 97%

“…In order to further quantify the relationship between water film and reduced gas flow in rock channels, the average thickness of the water film covering pore walls in the core samples following WPT damage was determined by using an empirical formula below 38 : where h (nm) is the thickness of water film, φ (%) is the rock porosity, S wirr (%) is the core irreducible water saturation after drainage, A (m 2 /g) is the rock-specific surface area, and ρ (g/ cm 3 ) is the rock density. Based on the experimental data obtained in this study, the thickness of the water film and the reduced pore size can be calculated using formulas (2) and (3). Calculation results are listed in Table 4 and show that the calculated thickness of water film was 21.22-38.18 nm, with an average of 27.37 nm.…”

Section: Changing Of Effective Gas Flow Channel During Wptmentioning

confidence: 97%

“…Preliminary development of unconventional gas resources in the United States can be traced back to the 1970s, and development of unconventional gas resources is expected to continue long into the future as industry strives to optimize recovery of worldwide energy resources. The total volume of global unconventional gas resources, which includes tight gas, shale gas, and coalbed methane (CBM), is over 8 times the volume of conventional gas resources, and the recoverable volume of these resources is estimated to be 920 × 10 12 m 3 . The economic potential of efficiently developing these unconventional gas resources is clearly very significant.…”

Section: Introductionmentioning

confidence: 99%

“…The total volume of global unconventional gas resources, which includes tight gas, shale gas, and coalbed methane (CBM), is over 8 times the volume of conventional gas resources, 1,2 and the recoverable volume of these resources is estimated to be 920 × 10 12 m 3 . 3 The economic potential of efficiently developing these unconventional gas resources is clearly very significant.…”

Section: Introductionmentioning

confidence: 99%

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Investigation of the controlling rock petrophysical factors on water phase trapping damage in tight gas reservoirs

Tian

Kang

Jia

et al. 2019

Energy Science & Engineering

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This paper presents an investigation into the effect of rock physical parameters on water phase trapping (WPT) damage in tight gas reservoirs. The investigation involved water imbibition and drainage experiments that were performed to simulate the WPT formation process. Gas permeability was measured before and after WPT, and an empirical formula was used to determine water film thickness in order to examine the influence of WPT on effective gas flow channel. Results showed that the average water saturation of 15 tight core samples increased from 19.41% to 44.76% during water imbibition and declined to 38.72% after drainage. Increments in water saturation caused a degree of damage to gas permeability in the 36.03%‐78.10% range with an average value of 59.31%. Comparative analysis showed that the dominant factors affecting WPT were average pore throat radius followed by rock permeability and porosity. Meanwhile, calculations showed that water film thickness in the 21.22‐38.18 nm range correlated to a reduced effective gas flow channel of 20.20‐45.15 nm caused by WPT, which suggests that tight rocks with smaller pore throats may be particularly sensitive to WPT damage. The relative size of the water film filling the pore throat, trapping gas, and reducing the effective gas flow channel together with the size of the pore throat itself were found to be the most common damage mechanisms of WPT and have proven to be fundamentally beneficial in understanding the controlling factors of these damage mechanisms.

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Section: Discussionmentioning

confidence: 97%

Section: Changing Of Effective Gas Flow Channel During Wptmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Investigation of the controlling rock petrophysical factors on water phase trapping damage in tight gas reservoirs

Tian

Kang

Jia

et al. 2019

Energy Science & Engineering

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“…In recent years, unconventional petroleum exploration, especially shale gas, has drawn the interest of researchers all over the world (Curtis, 2002;Ewing, 2006;Hill et al, 2007;Zou, 2014;Guo, 2014). Shale gas resource assessment has been carried out by many institutions, as the huge amount of shale gas resources not only relates to the formulation of national energy development strategies, but also directly affects the exploration work of oil companies (Zou et al, 2018;Ma et al, 2018;Chen et al, , 2019Yang and Zou, 2019). For basins with little drilling, the volumetric method is a commonly used resource assessment method, in which effective porosity (abbreviated to 'porosity') is the dominant parameter.…”

Section: Introductionmentioning

confidence: 99%

Reservoir Porosity Measurement Uncertainty and its Influence on Shale Gas Resource Assessment

Tian

Zou

Liu

et al. 2020

Acta Geologica Sinica (Eng)

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Reservoir porosity is a critical parameter for the process of unconventional oil and gas resources assessment. It is difficult to determine the porosity of a gas shale reservoir, and any large deviation will directly reduce the credibility of any shale gas resources evaluation. However, there is no quantitative explanation for the accuracy of porosity measurement. In this paper, measurement uncertainty, an internationally recognized index, was used to evaluate the results of porosity measurement of gas shale plugs, and its impact on the credibility of shale gas resources assessment was determined. The following conclusions are drawn: (1) the measurement uncertainty of porosity of a shale plug is 1.76%-3.12% using current measurement methods, the upper end of which is too large to be acceptable. It is suggested that the measurement uncertainty should be factored into the standard helium gas injection porosity determination experiment, and the uncertainty should be less than 2.00% when using a high-precision pressure gauge; (2) in order to reduce the risk for exploration and decision-making, attention should be paid to the large uncertainty (30% at least) of shale gas resource assessment results, sometimes with corrections being made based on the practical considerations;(3) a pressure gauge with an accuracy of 0.25% of the full scal cannot meet the requirements of porosity measurement, and a high-precision plug cutting method or high-precision bulk volume measurement method such as one using 3D scanning, is recommended to effectively reduce porosity uncertainty; (4) the method and process for evaluating the measurement uncertainty of gas shale porosity could also be referred for assessment of experimental quality by other laboratories.

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Longitudinal interference analysis of shale gas multi‐stage fracturing horizontal wells upon high‐precision pressure test

Gao

Liu

Pan

et al. 2020

Energy Science & Engineering

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Shale gas plays a crucial role in the national energy supply. However, fast pressure drop, production decline, and water resources pollution caused by well interference and fracture hits become more severe in multi‐layer mining shale gas fields. Such as, it is urgent to evaluate the interference of multi‐stage fracturing horizontal wells (MFHWs) between the upper and lower gas layers in Chinese Jiaoshiba shale gas field. Therefore, we put forward a comprehensive method to analyze the MFHW interference in this paper. The method contains bottom‐hole pressure response analysis (BHPRA) during neighboring well fracturing, BHPRA of well interference test, and production dynamic analysis. Our study indicates that longitudinal pressure interference exists between the Jiaoshiba upper and lower gas layers upon the apparent interference pressure response in a multi‐well test. However, MFHW interferences occur in the corresponding fracturing stages with shorter distance, and the interference strength is related to both well distance and fracturing scales. The Jiaoshiba upper gas layers can be developed to increase the gas production performance, but it is necessary to maintain a reasonable well spacing to avoid severe interference during the development.

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Theory, technology and prospects of conventional and unconventional natural gas

Cited by 241 publications

References 8 publications

Investigation of the controlling rock petrophysical factors on water phase trapping damage in tight gas reservoirs

Investigation of the controlling rock petrophysical factors on water phase trapping damage in tight gas reservoirs

Reservoir Porosity Measurement Uncertainty and its Influence on Shale Gas Resource Assessment

Longitudinal interference analysis of shale gas multi‐stage fracturing horizontal wells upon high‐precision pressure test

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