Application of zipper-fracturing of horizontal cluster wells in the Changning shale gas pilot zone, Sichuan Basin

Qian, Bin; Zhang, Juncheng; Zhu, Juhui; Fang, Zeben; Kou, Shuangfeng; Chen, Rui

doi:10.1016/j.ngib.2015.07.008

Cited by 17 publications

(8 citation statements)

References 3 publications

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“…A shale reservoir has low porosity and poor permeability . It is necessary to perform reservoir stimulation to develop a shale reservoir, and hydraulic fracturing is a mature technology. , However, the injected fluid can easily cause clay expansion, resulting in reservoir damage. , In addition, huge water consumption during hydraulic fracturing is undoubtedly a serious challenge for water shortage areas . Therefore, anhydrous fracturing technology, such as supercritical CO 2 fracturing technology, has become a potential method for shale gas exploitation …”

Section: Introductionmentioning

confidence: 99%

“…3 It is necessary to perform reservoir stimulation to develop a shale reservoir, and hydraulic fracturing is a mature technology. 4,5 However, the injected fluid can easily cause clay expansion, resulting in reservoir damage. 6,7 In addition, huge water consumption during hydraulic fracturing is undoubtedly a serious challenge for water shortage areas.…”

Section: Introductionmentioning

confidence: 99%

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Molecular Simulation of Diffusion and Competitive Sorption of CH₄ and CO₂ in Shale Nanopores

et al. 2022

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Based on the competitive adsorption of CH 4 and CO 2 , molecular dynamics (MD) and Grand Canonical Monte Carlo (GCMC) are used to study the mechanism of increasing shale gas recovery by carbon dioxide injection. The influence of different factors on the diffusion capacity of CH 4 in unrestricted space and restricted space is analyzed, and the diffusion capacities of CH 4 and CO 2 in shale nanopores are compared. Under different conditions, the difference in the sorption amount and sorption heat of CH 4 and CO 2 is studied, and the displacement simulation of CH 4 and CO 2 is conducted. The obtained results show that the diffusion capacity of CH 4 in restricted space is much smaller than that in unrestricted space, and the difference between them is related to temperature, pressure, and pore size. When pressure exceeds 10 MPa, the difference gradually decreases. The diffusion capacity of CO 2 is weaker than that of CH 4 under the same conditions, which contributes to the retention of CO 2 . There is a competitive sorption relationship between CH 4 and CO 2 . The sorption amount and sorption heat of CH 4 and CO 2 are affected by the combination of pressure, temperature, density ratio, pore size, and mineral type. The adsorption capacity of CO 2 is much higher than that of CH 4 . When sorption conditions are more favorable, the adsorption difference between CH 4 and CO 2 will become larger. In shale nanopores, CO 2 can replace CH 4 that is adsorbed on the pore surface to improve shale gas recovery.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Molecular Simulation of Diffusion and Competitive Sorption of CH₄ and CO₂ in Shale Nanopores

et al. 2022

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“…Because of its extensive distribution and massive reserve in the world, shale gas has a great potential in energy supply . In recent years, the development of advanced horizontal well techniques and hydraulic fracturing technology has enabled some countries to economically exploit shale gas. , The United States is the first country to commercially develop shale gas, and its annual shale gas production is about 1.0 Tcf from over 40,000 shale gas wells in five primary basins, which helps America improve its energy security and depresses the natural gas prices. In the recent few years, Canada and China have also made breakthroughs in the development of shale gas, − and many other nations are also pursuing the opportunity to develop shale gas.…”

Section: Introductionmentioning

confidence: 99%

Study of CO₂ Enhancing Shale Gas Recovery Based on Competitive Adsorption Theory

Sun

et al. 2020

ACS Omega

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As an indispensable part of unconventional natural gas resources, the shale reservoir is huge and widely distributed. It is of great significance to study how to enhance the shale gas recovery for improving the energy structure. In order to solve the problem of low gas production rate and long recovery period in the process of shale gas production, in this paper, the influences of pressure, temperature, moisture, and gas type on isothermal adsorption and desorption of shale gas are analyzed based on shale adsorption and desorption experiments, and the adsorption and desorption abilities of CO 2 and CH 4 in shale are compared to verify the feasibility of CO 2 enhancing shale gas recovery. Depletion production experiments and CO 2 injection experiments with different injection pressures (6 and 7 MPa), different injection rates (5, 10 and 20 mL/min), and different injection amounts are carried out. The mechanism of CO 2 enhancing shale gas recovery is proposed, and the parameters of CO 2 injection are optimized. The results show that the adsorption capacity of CH 4 increases with the increase in pressure and the decrease in temperature and moisture in a certain range. Under the same experimental conditions, the sorting of adsorption capacity is CO 2 > CH 4 > N 2 , while desorption capacity is CH 4 > CO 2 > N 2 . The desorption curves of the three gases lag behind the adsorption curves, in which the lag phenomenon of CO 2 is most obvious. The ultimate recovery of depletion production ranges from 66 to 73%. CO 2 injection can effectively increase the gas production rate of CH 4 , and it can also keep the cumulative gas production of CH 4 growing steadily and rapidly. Within a certain range, CH 4 recovery increases with the increase in CO 2 injection pressure, the injection rate, and injection amount, but its increase range is related to the porosity and permeability of shale.

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“…8 Hitherto, the application of advanced hydraulic fracturing significantly enhances the gas production efficiency of an individual well and also the stimulated formation volume. 9 To implement multi-stage hydraulic fracturing in shale gas reservoirs, usually 10 000−75 000 m 3 water with proppants per well are injected into the formation under high pressures. 10 However, in some cases, only less than 30% of the injected water is recovered during production (could be higher depending upon the shale plays).…”

Section: Introductionmentioning

confidence: 99%

“…However, in comparison to conventional reservoirs, such as sandstone, the shale reservoirs have a relatively low permeability (from nanodarcy to millidarcy), which prevents the economic development without stimulations, such as multi-stage hydraulic fracturing, , that can create new fractures and activate natural fractures . Hitherto, the application of advanced hydraulic fracturing significantly enhances the gas production efficiency of an individual well and also the stimulated formation volume …”

Section: Introductionmentioning

confidence: 99%

Interpreting Water Uptake by Shale with Ion Exchange, Surface Complexation, and Disjoining Pressure

Zeng

Chen

et al. 2019

Energy Fuels

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Multi-stage hydraulic fracturing is a commonly used method to maximize production from shale gas reservoirs. However, the recovery of flowback water after hydraulic fracturing is relatively low, which gives rise to technical and environmental concerns. Although it is widely accepted that the water uptake is due to physicochemical fluid–shale interactions caused by the capillary forces, much of the studies up to now are just descriptive in nature and little attention has been paid to quantitatively characterize the fluid–shale interactions and, thus, surface forces from a geochemical perspective. In this study, we performed geochemical modeling to explain the results of spontaneous imbibition experiments by published work. We calculated the surface potential of organic matter, quartz, and calcite in the presence of 0.1–20 wt % NaCl. Moreover, we predicted the local pH using PHREEQC with consideration of ion exchange and mineral dissolution. We also computed the disjoining pressure under constant charge conditions. Results show that a low salinity drives the surface potential of organic matter and inorganic minerals to strongly negative at in situ pH. The disjoining pressure isotherm shows that air–brine–organic matter and air–brine–calcite systems give positive disjoining pressure regardless of salinity, implying a water-wet system. Moreover, a low salinity shifts the disjoining pressure to be more positive for organic matter, suggesting a wettability alteration process. However, the change of disjoining pressure on the calcite surface is negligible as a function of salinity. Our results confirm that capillary forces at least partially contribute to the water uptake, and the presence of organic matter likely further facilitates the water uptake as a result of wettability alteration. This explains in part why a low salinity causes shale expansion and microfracture generation in organic-rich reservoirs.

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Application of zipper-fracturing of horizontal cluster wells in the Changning shale gas pilot zone, Sichuan Basin

Cited by 17 publications

References 3 publications

Molecular Simulation of Diffusion and Competitive Sorption of CH₄ and CO₂ in Shale Nanopores

Molecular Simulation of Diffusion and Competitive Sorption of CH₄ and CO₂ in Shale Nanopores

Study of CO₂ Enhancing Shale Gas Recovery Based on Competitive Adsorption Theory

Interpreting Water Uptake by Shale with Ion Exchange, Surface Complexation, and Disjoining Pressure

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Application of zipper-fracturing of horizontal cluster wells in the Changning shale gas pilot zone, Sichuan Basin

Cited by 17 publications

References 3 publications

Molecular Simulation of Diffusion and Competitive Sorption of CH4 and CO2 in Shale Nanopores

Molecular Simulation of Diffusion and Competitive Sorption of CH4 and CO2 in Shale Nanopores

Study of CO2 Enhancing Shale Gas Recovery Based on Competitive Adsorption Theory

Interpreting Water Uptake by Shale with Ion Exchange, Surface Complexation, and Disjoining Pressure

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Product

Resources

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Molecular Simulation of Diffusion and Competitive Sorption of CH₄ and CO₂ in Shale Nanopores

Molecular Simulation of Diffusion and Competitive Sorption of CH₄ and CO₂ in Shale Nanopores

Study of CO₂ Enhancing Shale Gas Recovery Based on Competitive Adsorption Theory