The Experts below are selected from a list of 20514 Experts worldwide ranked by ideXlab platform
Cheng Zhai - One of the best experts on this subject based on the ideXlab platform.
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pulsating Hydraulic Fracturing technology in low permeability coal seams
International journal of mining science and technology, 2015Co-Authors: Wenchao Wang, Xianzhong Li, Cheng ZhaiAbstract:Abstract Based on the difficult situation of gas drainage in a single coal bed of high gas content and low permeability, we investigate the technology of pulsating Hydraulic pressure relief, the process of crank plunger movement and the mechanism of pulsating pressure formation using theoretical research, mathematical modeling and field testing. We analyze the effect of pulsating pressure on the formation and growth of fractures in coal by using the pulsating Hydraulic theory in Hydraulics. The research results show that the amplitude of fluctuating pressure tends to increase in the case where the exit is blocked, caused by pulsating pressure reflection and frictional resistance superposition, and it contributes to the growth of fractures in coal. The crack initiation pressure of pulsating Hydraulic Fracturing is 8 MPa, which is half than that of normal Hydraulic Fracturing; the pulsating Hydraulic Fracturing influence radius reaches 8 m. The total amount of gas extraction is increased by 3.6 times, and reaches 50 L/min at the highest point. The extraction flow increases greatly, and is 4 times larger than that of drilling without Fracturing and 1.2 times larger than that of normal Hydraulic Fracturing. The technology provides a technical measure for gas drainage of high gas content and low permeability in the single coal bed.
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Pulsating Hydraulic Fracturing technology in low permeability coal seams
Elsevier, 2015Co-Authors: Wenchao Wang, Baiquan Lin, Cheng ZhaiAbstract:Based on the difficult situation of gas drainage in a single coal bed of high gas content and low permeability, we investigate the technology of pulsating Hydraulic pressure relief, the process of crank plunger movement and the mechanism of pulsating pressure formation using theoretical research, mathematical modeling and field testing. We analyze the effect of pulsating pressure on the formation and growth of fractures in coal by using the pulsating Hydraulic theory in Hydraulics. The research results show that the amplitude of fluctuating pressure tends to increase in the case where the exit is blocked, caused by pulsating pressure reflection and frictional resistance superposition, and it contributes to the growth of fractures in coal. The crack initiation pressure of pulsating Hydraulic Fracturing is 8 MPa, which is half than that of normal Hydraulic Fracturing; the pulsating Hydraulic Fracturing influence radius reaches 8 m. The total amount of gas extraction is increased by 3.6 times, and reaches 50 L/min at the highest point. The extraction flow increases greatly, and is 4 times larger than that of drilling without Fracturing and 1.2 times larger than that of normal Hydraulic Fracturing. The technology provides a technical measure for gas drainage of high gas content and low permeability in the single coal bed. Keywords: Gas drainage, Pulsating Hydraulic Fracturing, Fatigue damage, Permeability improvemen
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variable frequency of pulse Hydraulic Fracturing for improving permeability in coal seam
International journal of mining science and technology, 2013Co-Authors: Baiquan Lin, Cheng Zhai, Shen Peng, Chen Sun, Yanying ChengAbstract:Abstract Variable frequency, a new pattern of pulse Hydraulic Fracturing, is presented for improving permeability in coal seam. A variable frequency pulse Hydraulic Fracturing testing system was built, the mould with triaxial loading was developed. Based on the monitor methods of pressure sensor and acoustic emission, the trials of two patterns of pulse Hydraulic Fracturing of single frequency and variable frequency were carried out, and at last Fracturing mechanism was analyzed. The results show that the effect of variable frequency on fracture extension is better than that of single frequency based on the analysis of macroscopic figures and AE. And the shortage of single frequency is somewhat remedied when the frequency is variable. Under variable frequency, the pressure process can be divided into three stages: low frequency band, pressure stability band and high frequency band, and rupture pressure of the sample is smaller than that of the condition of single frequency. Based on the Miner fatigue theory, the effect of different loading sequences on sample rupture is discussed and the results show that it is better to select the sequence of low frequency at first and then high frequency. Our achievements can give a basis for the improvement and optimization of the pulse Hydraulic Fracturing technology.
Anna L Harrison - One of the best experts on this subject based on the ideXlab platform.
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Shale Kerogen: Hydraulic Fracturing Fluid Interactions and Contaminant Release
2018Co-Authors: Megan K. Dustin, Anna L Harrison, Dana L Thomas, John R Bargar, Gordon E Brown, Adam D. Jew, Claresta Joe-wong, Kate MaherAbstract:The recent increase in unconventional oil and gas exploration and production has prompted a large amount of research on Hydraulic Fracturing, but the majority of chemical reactions between shale minerals and organic matter with Fracturing fluids are not well understood. Organic matter, primarily in the form of kerogen, dominates the transport pathways for oil and gas; thus any alteration of kerogen (both physical and chemical properties) upon exposure to Fracturing fluid may impact hydrocarbon extraction. In addition, kerogen is enriched in metals, making it a potential source of heavy metal contaminants to produced waters. In this study, we reacted two different kerogen isolates of contrasting type and maturity (derived from Green River and Marcellus shales) with a synthetic Hydraulic Fracturing fluid for 2 weeks in order to determine the effect of Fracturing fluids on both shale organic matter and closely associated minerals. ATR-FTIR results show that the functional group compositions of the kerogen isolates were in fact altered, although by apparently different mechanisms. In particular, hydrophobic functional groups decreased in the Marcellus kerogen, which suggests the wettability of shale organic matter may be susceptible to alteration during Hydraulic Fracturing operations. About 1% of organic carbon in the more immature and Type I Green River kerogen isolate was solubilized when it was exposed to Fracturing fluid, and the released organic compounds significantly impacted Fe oxidation. On the basis of the alteration observed in both kerogen isolates, it should not be assumed that kerogenic pores are chemically inert over the time frame of Hydraulic Fracturing operations. Shifts in functional group composition and loss of hydrophobicity have the potential to degrade transport and storage parameters such as wettability, which could alter hydrocarbon and Fracturing fluid transport through shale. Additionally, reaction of Green River and Marcellus kerogen isolates with low pH solutions (full Fracturing fluid, which contains hydrochloric acid, or pH 2 water) mobilized potential trace metal(loid) contaminants, primarily S, Fe, Co, Ni, Zn, and Pb. The source of trace metal(loid)s varied between the two kerogen isolates, with metals in the Marcellus shale largely sourced from pyrite impurities, whereas metals in the Green River shale were sourced from a combination of accessory minerals and kerogen
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element release and reaction induced porosity alteration during shale Hydraulic Fracturing fluid interactions
Applied Geochemistry, 2017Co-Authors: Anna L Harrison, Megan K Dustin, Dana L Thomas, Claresta Joewong, John R Bargar, Natalie Johnson, Gordon E Brown, Katharine MaherAbstract:The use of Hydraulic Fracturing techniques to extract oil and gas from low permeability shale reservoirs has increased significantly in recent years. During Hydraulic Fracturing, large volumes of water, often acidic and oxic, are injected into shale formations. This drives fluid-rock interaction that can release metal contaminants (e.g., U, Pb) and alter the permeability of the rock, impacting the transport and recovery of water, hydrocarbons, and contaminants. To identify the key geochemical processes that occur upon exposure of shales to Hydraulic Fracturing fluid, we investigated the chemical interaction of Hydraulic Fracturing fluids with a variety of shales of different mineralogical texture and composition. Batch reactor experiments revealed that the dissolution of both pyrite and carbonate minerals occurred rapidly, releasing metal contaminants and generating porosity. Oxidation of pyrite and aqueous Fe drove precipitation of Fe(III)-(oxy)hydroxides that attenuated the release of these contaminants via co-precipitation and/or adsorption. The precipitation of these (oxy)hydroxides appeared to limit the extent of pyrite reaction. Enhanced removal of metals and contaminants in reactors with higher fluid pH was inferred to reflect increased Fe-(oxy)hydroxide precipitation associated with more rapid aqueous Fe(II) oxidation. The precipitation of both Al- and Fe-bearing phases revealed the potential for the occlusion of pores and fracture apertures, whereas the selective dissolution of calcite generated porosity. These pore-scale alterations of shale texture and the cycling of contaminants indicate that chemical interactions between shales and Hydraulic Fracturing fluids may exert an important control on the efficiency of Hydraulic Fracturing operations and the quality of water recovered at the surface.
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element release and reaction induced porosity alteration during shale Hydraulic Fracturing fluid interactions
Applied Geochemistry, 2017Co-Authors: Anna L Harrison, Megan K Dustin, Dana L Thomas, Claresta Joewong, John R Bargar, Natalie Johnson, Gordon E Brown, Katharine MaherAbstract:The use of Hydraulic Fracturing techniques to extract oil and gas from low permeability shale reservoirs has increased significantly in recent years. During Hydraulic Fracturing, large volumes of water, often acidic and oxic, are injected into shale formations. This drives fluid-rock interaction that can release metal contaminants (e.g., U, Pb) and alter the permeability of the rock, impacting the transport and recovery of water, hydrocarbons, and contaminants. To identify the key geochemical processes that occur upon exposure of shales to Hydraulic Fracturing fluid, we investigated the chemical interaction of Hydraulic Fracturing fluids with a variety of shales of different mineralogical texture and composition. Batch reactor experiments revealed that the dissolution of both pyrite and carbonate minerals occurred rapidly, releasing metal contaminants and generating porosity. Oxidation of pyrite and aqueous Fe drove precipitation of Fe(III)-(oxy)hydroxides that attenuated the release of these contaminants via co-precipitation and/or adsorption. The precipitation of these (oxy)hydroxides appeared to limit the extent of pyrite reaction. Enhanced removal of metals and contaminants in reactors with higher fluid pH was inferred to reflect increased Fe-(oxy)hydroxide precipitation associated with more rapid aqueous Fe(II) oxidation. The precipitation of both Al- and Fe-bearing phases revealed the potential for the occlusion of pores and fracture apertures, whereas the selective dissolution of calcite generated porosity. These pore-scale alterations of shale texture and the cycling of contaminants indicate that chemical interactions between shales and Hydraulic Fracturing fluids may exert an important control on the efficiency of Hydraulic Fracturing operations and the quality of water recovered at the surface.
Jingchen Zhang - One of the best experts on this subject based on the ideXlab platform.
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numerical simulation of Hydraulic Fracturing coalbed methane reservoir
Fuel, 2014Co-Authors: Jingchen ZhangAbstract:Abstract Some coal seam is well known for its three low characteristics: low permeability, low reservoir pressure and low gas saturation. Thus stimulation measures must be taken during coalbed methane development stage to enhance its recovery. Hydraulic Fracturing transformation technology is an effective method for increasing coalbed methane production. This paper presents a two-phase, 3D flow and Hydraulic Fracturing model of dual-porosity media based on the theories of oil–gas geology and mechanics of flow through porous media. Correspondingly, a finite difference numerical model has been developed and applied successfully to a coalbed methane reservoir. Well test data from one western China basin is utilized for simulation. Results show that Hydraulic Fracturing promotes desorption and diffusion of coalbed methane which in turn substantially increases production of coalbed methane.
Gordon E Brown - One of the best experts on this subject based on the ideXlab platform.
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Shale Kerogen: Hydraulic Fracturing Fluid Interactions and Contaminant Release
2018Co-Authors: Megan K. Dustin, Anna L Harrison, Dana L Thomas, John R Bargar, Gordon E Brown, Adam D. Jew, Claresta Joe-wong, Kate MaherAbstract:The recent increase in unconventional oil and gas exploration and production has prompted a large amount of research on Hydraulic Fracturing, but the majority of chemical reactions between shale minerals and organic matter with Fracturing fluids are not well understood. Organic matter, primarily in the form of kerogen, dominates the transport pathways for oil and gas; thus any alteration of kerogen (both physical and chemical properties) upon exposure to Fracturing fluid may impact hydrocarbon extraction. In addition, kerogen is enriched in metals, making it a potential source of heavy metal contaminants to produced waters. In this study, we reacted two different kerogen isolates of contrasting type and maturity (derived from Green River and Marcellus shales) with a synthetic Hydraulic Fracturing fluid for 2 weeks in order to determine the effect of Fracturing fluids on both shale organic matter and closely associated minerals. ATR-FTIR results show that the functional group compositions of the kerogen isolates were in fact altered, although by apparently different mechanisms. In particular, hydrophobic functional groups decreased in the Marcellus kerogen, which suggests the wettability of shale organic matter may be susceptible to alteration during Hydraulic Fracturing operations. About 1% of organic carbon in the more immature and Type I Green River kerogen isolate was solubilized when it was exposed to Fracturing fluid, and the released organic compounds significantly impacted Fe oxidation. On the basis of the alteration observed in both kerogen isolates, it should not be assumed that kerogenic pores are chemically inert over the time frame of Hydraulic Fracturing operations. Shifts in functional group composition and loss of hydrophobicity have the potential to degrade transport and storage parameters such as wettability, which could alter hydrocarbon and Fracturing fluid transport through shale. Additionally, reaction of Green River and Marcellus kerogen isolates with low pH solutions (full Fracturing fluid, which contains hydrochloric acid, or pH 2 water) mobilized potential trace metal(loid) contaminants, primarily S, Fe, Co, Ni, Zn, and Pb. The source of trace metal(loid)s varied between the two kerogen isolates, with metals in the Marcellus shale largely sourced from pyrite impurities, whereas metals in the Green River shale were sourced from a combination of accessory minerals and kerogen
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element release and reaction induced porosity alteration during shale Hydraulic Fracturing fluid interactions
Applied Geochemistry, 2017Co-Authors: Anna L Harrison, Megan K Dustin, Dana L Thomas, Claresta Joewong, John R Bargar, Natalie Johnson, Gordon E Brown, Katharine MaherAbstract:The use of Hydraulic Fracturing techniques to extract oil and gas from low permeability shale reservoirs has increased significantly in recent years. During Hydraulic Fracturing, large volumes of water, often acidic and oxic, are injected into shale formations. This drives fluid-rock interaction that can release metal contaminants (e.g., U, Pb) and alter the permeability of the rock, impacting the transport and recovery of water, hydrocarbons, and contaminants. To identify the key geochemical processes that occur upon exposure of shales to Hydraulic Fracturing fluid, we investigated the chemical interaction of Hydraulic Fracturing fluids with a variety of shales of different mineralogical texture and composition. Batch reactor experiments revealed that the dissolution of both pyrite and carbonate minerals occurred rapidly, releasing metal contaminants and generating porosity. Oxidation of pyrite and aqueous Fe drove precipitation of Fe(III)-(oxy)hydroxides that attenuated the release of these contaminants via co-precipitation and/or adsorption. The precipitation of these (oxy)hydroxides appeared to limit the extent of pyrite reaction. Enhanced removal of metals and contaminants in reactors with higher fluid pH was inferred to reflect increased Fe-(oxy)hydroxide precipitation associated with more rapid aqueous Fe(II) oxidation. The precipitation of both Al- and Fe-bearing phases revealed the potential for the occlusion of pores and fracture apertures, whereas the selective dissolution of calcite generated porosity. These pore-scale alterations of shale texture and the cycling of contaminants indicate that chemical interactions between shales and Hydraulic Fracturing fluids may exert an important control on the efficiency of Hydraulic Fracturing operations and the quality of water recovered at the surface.
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element release and reaction induced porosity alteration during shale Hydraulic Fracturing fluid interactions
Applied Geochemistry, 2017Co-Authors: Anna L Harrison, Megan K Dustin, Dana L Thomas, Claresta Joewong, John R Bargar, Natalie Johnson, Gordon E Brown, Katharine MaherAbstract:The use of Hydraulic Fracturing techniques to extract oil and gas from low permeability shale reservoirs has increased significantly in recent years. During Hydraulic Fracturing, large volumes of water, often acidic and oxic, are injected into shale formations. This drives fluid-rock interaction that can release metal contaminants (e.g., U, Pb) and alter the permeability of the rock, impacting the transport and recovery of water, hydrocarbons, and contaminants. To identify the key geochemical processes that occur upon exposure of shales to Hydraulic Fracturing fluid, we investigated the chemical interaction of Hydraulic Fracturing fluids with a variety of shales of different mineralogical texture and composition. Batch reactor experiments revealed that the dissolution of both pyrite and carbonate minerals occurred rapidly, releasing metal contaminants and generating porosity. Oxidation of pyrite and aqueous Fe drove precipitation of Fe(III)-(oxy)hydroxides that attenuated the release of these contaminants via co-precipitation and/or adsorption. The precipitation of these (oxy)hydroxides appeared to limit the extent of pyrite reaction. Enhanced removal of metals and contaminants in reactors with higher fluid pH was inferred to reflect increased Fe-(oxy)hydroxide precipitation associated with more rapid aqueous Fe(II) oxidation. The precipitation of both Al- and Fe-bearing phases revealed the potential for the occlusion of pores and fracture apertures, whereas the selective dissolution of calcite generated porosity. These pore-scale alterations of shale texture and the cycling of contaminants indicate that chemical interactions between shales and Hydraulic Fracturing fluids may exert an important control on the efficiency of Hydraulic Fracturing operations and the quality of water recovered at the surface.
Katharine Maher - One of the best experts on this subject based on the ideXlab platform.
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element release and reaction induced porosity alteration during shale Hydraulic Fracturing fluid interactions
Applied Geochemistry, 2017Co-Authors: Anna L Harrison, Megan K Dustin, Dana L Thomas, Claresta Joewong, John R Bargar, Natalie Johnson, Gordon E Brown, Katharine MaherAbstract:The use of Hydraulic Fracturing techniques to extract oil and gas from low permeability shale reservoirs has increased significantly in recent years. During Hydraulic Fracturing, large volumes of water, often acidic and oxic, are injected into shale formations. This drives fluid-rock interaction that can release metal contaminants (e.g., U, Pb) and alter the permeability of the rock, impacting the transport and recovery of water, hydrocarbons, and contaminants. To identify the key geochemical processes that occur upon exposure of shales to Hydraulic Fracturing fluid, we investigated the chemical interaction of Hydraulic Fracturing fluids with a variety of shales of different mineralogical texture and composition. Batch reactor experiments revealed that the dissolution of both pyrite and carbonate minerals occurred rapidly, releasing metal contaminants and generating porosity. Oxidation of pyrite and aqueous Fe drove precipitation of Fe(III)-(oxy)hydroxides that attenuated the release of these contaminants via co-precipitation and/or adsorption. The precipitation of these (oxy)hydroxides appeared to limit the extent of pyrite reaction. Enhanced removal of metals and contaminants in reactors with higher fluid pH was inferred to reflect increased Fe-(oxy)hydroxide precipitation associated with more rapid aqueous Fe(II) oxidation. The precipitation of both Al- and Fe-bearing phases revealed the potential for the occlusion of pores and fracture apertures, whereas the selective dissolution of calcite generated porosity. These pore-scale alterations of shale texture and the cycling of contaminants indicate that chemical interactions between shales and Hydraulic Fracturing fluids may exert an important control on the efficiency of Hydraulic Fracturing operations and the quality of water recovered at the surface.
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element release and reaction induced porosity alteration during shale Hydraulic Fracturing fluid interactions
Applied Geochemistry, 2017Co-Authors: Anna L Harrison, Megan K Dustin, Dana L Thomas, Claresta Joewong, John R Bargar, Natalie Johnson, Gordon E Brown, Katharine MaherAbstract:The use of Hydraulic Fracturing techniques to extract oil and gas from low permeability shale reservoirs has increased significantly in recent years. During Hydraulic Fracturing, large volumes of water, often acidic and oxic, are injected into shale formations. This drives fluid-rock interaction that can release metal contaminants (e.g., U, Pb) and alter the permeability of the rock, impacting the transport and recovery of water, hydrocarbons, and contaminants. To identify the key geochemical processes that occur upon exposure of shales to Hydraulic Fracturing fluid, we investigated the chemical interaction of Hydraulic Fracturing fluids with a variety of shales of different mineralogical texture and composition. Batch reactor experiments revealed that the dissolution of both pyrite and carbonate minerals occurred rapidly, releasing metal contaminants and generating porosity. Oxidation of pyrite and aqueous Fe drove precipitation of Fe(III)-(oxy)hydroxides that attenuated the release of these contaminants via co-precipitation and/or adsorption. The precipitation of these (oxy)hydroxides appeared to limit the extent of pyrite reaction. Enhanced removal of metals and contaminants in reactors with higher fluid pH was inferred to reflect increased Fe-(oxy)hydroxide precipitation associated with more rapid aqueous Fe(II) oxidation. The precipitation of both Al- and Fe-bearing phases revealed the potential for the occlusion of pores and fracture apertures, whereas the selective dissolution of calcite generated porosity. These pore-scale alterations of shale texture and the cycling of contaminants indicate that chemical interactions between shales and Hydraulic Fracturing fluids may exert an important control on the efficiency of Hydraulic Fracturing operations and the quality of water recovered at the surface.
